El papel de los rayos UV en la enfermedad ocular

<div dir="ltr" style="text-align: left;" trbidi="on"> Visualizacion optima 1600x900 pixel Comenta.esta.publicación<br /> <span style="background-color: #fefefd; color: #333333; font-family: Tahoma, Arial, Helvetica, sans-serif; font-size: 13px; font-style: italic; font-weight: bold;">or Paul Karpecki, OD, FAAO</span> <br /> <span style="background-color: #fefefd; color: #333333; font-family: Tahoma, Arial, Helvetica, sans-serif; font-size: 13px; font-style: italic; font-weight: bold;"><br /></span> <br /> <h2 style="background-color: #fefefd; color: #1b4475; font-family: Arial, Helvetica, sans-serif; font-size: 12pt; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> <span style="font-family: Tahoma, Arial, Helvetica, sans-serif;">OBJETIVO DECLARACIÓN:</span></h2> <div style="background-color: #fefefd; color: #333333; font-family: Arial, Helvetica, sans-serif; font-size: 13px; margin-bottom: 12px;"> <span style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Optometristas han sabido por mucho tiempo el impacto de la radiación ultravioleta (UV) la luz que puede resultar en el desarrollo de catarata relacionada con la edad degeneración macular e incluso pterigión o pinguecula.</span> <span style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Este curso se ve en la última comprensión de la exposición UV y algunos de los más comunes, así como las enfermedades raras que optometristas enfrentan cuando se trata a los rayos UV.</span></div> <div style="background-color: #fefefd; color: #333333; font-family: Arial, Helvetica, sans-serif; font-size: 13px; margin-bottom: 12px;"> <span style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><br /></span></div> <div style="background-color: #fefefd; color: #333333; font-family: Arial, Helvetica, sans-serif; font-size: 13px; margin-bottom: 12px;"> </div> <h2 style="color: #1b4475; font-size: 12pt; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> FACULTY/EDITORIAL BOARD:</h2> <div style="margin-bottom: 12px;"> <strong style="font-family: Tahoma, Arial, Helvetica, sans-serif;"></strong>Paul Karpecki, OD, FAAO</div> <h2 style="color: #1b4475; font-size: 12pt; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> CREDIT STATEMENT:</h2> <div style="margin-bottom: 12px;"> This course is COPE approved for 2 hours of CE credit. COPE ID 35694-SD. Check with your local state licensing board to see if this counts toward your CE requirements for relicensure.</div> <h2 style="color: #1b4475; font-size: 12pt; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> JOINT-SPONSORSHIP STATEMENT:</h2> <div style="margin-bottom: 12px;"> This continuing education course is joint-sponsored by the University of Alabama School of Optometry and Essilor.</div> <h2 style="color: #1b4475; font-size: 12pt; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> DISCLOSURE STATEMENT:</h2> <div style="margin-bottom: 12px;"> The author is a consultant for AMO, Alcon, Bausch + Lomb, Focus Labs and OcuSoft and is a stock shareholder of TearLab.</div> <div style="margin-bottom: 12px;"> Dr. Karpecki is also on the Essilor Advisory Board, but has no financial interest in any products.</div> <hr style="color: dimgrey; font-family: Tahoma, Arial, Helvetica, sans-serif; height: 1pt;" /> <div style="margin-bottom: 12px;"> Optometrists have long known the impact of ultraviolet (UV) light radiation that can result in cataract development, age-related macular degeneration and even pterygia or pingueculae.</div> <div style="margin-bottom: 12px;"> But these conditions continue to increase in prevalence even though many contact lenses, IOLs and spectacles have UV protection coatings. This paper looks at the latest understanding of UV exposure and some of the more common as well as rare diseases that optometrists face when it comes to UV damage.</div> <h2 style="color: #1b4475; font-size: 12pt; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> UV EXPOSURE AND OCULAR HEALTH</h2> <div style="margin-bottom: 12px;"> There are three forms of ultraviolet light—UVA, UVB and UVC.</div> <div style="margin-bottom: 12px;"> UVA has a wavelength of 315nm to 380nm and penetrates deeply into the skin. This is often associated with tanning, but also is linked to skin aging.</div> <div style="margin-bottom: 12px;"> UVB has a wavelength that is even smaller, between 280nm to 315nm. UVB does not penetrate into the skin as deeply as UVA because the epidermis mostly absorbs it. Thus, it can be a more damaging form of ultraviolet light that can cause erythema or sunburn, blistering of the skin, and potentially various skin cancers.</div> <div style="margin-bottom: 12px;"> UVC ranges from 100nm to 280nm in wavelength and is the most harmful to the skin, also resulting in skin cancer. Fortunately, most of it is absorbed by the ozone layer and does not reach the Earth's surface.</div> <div style="margin-bottom: 12px;"> <br /></div> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEua81-Jk7uhkwS5FXbgKzBIvvZxpT51O3q8eIQ61dzxHG7eSRmxG2rLJPvDdIZlsakno2IPMQzYDVzxk6xoxCZSnscBzfVIbOYG9ku5NmZ-Lh7fnMPHkjR-HpzrF3MK4V1IcVI1rXdrk/s1600/fig1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhEua81-Jk7uhkwS5FXbgKzBIvvZxpT51O3q8eIQ61dzxHG7eSRmxG2rLJPvDdIZlsakno2IPMQzYDVzxk6xoxCZSnscBzfVIbOYG9ku5NmZ-Lh7fnMPHkjR-HpzrF3MK4V1IcVI1rXdrk/s1600/fig1.jpg" /></a></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;">Figure 1: A patient diagnosed with a conjunctival malignant melanoma.</strong> </div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;">The sunlight that does reach the Earth is comprised of approximately 95% UVA light and 5% UVB/UVC.</strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;">UVB and especially UVC are directly absorbed by DNA molecules, so this is why experts believe that these have the greatest impact on altering skin tissue and are associated with skin cancers.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">1</sup></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;">UVC is also the form that plays a key role in cataract genesis, as well as macular degeneration.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">2</sup> UVC can actually form free radicals that directly affect the DNA. This has the ability to disrupt structures such as collagen, which are prevalent in the cornea and conjunctiva, as well as glycans such as hyaluronic acid.</strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;">On the other hand, some sun exposure is critically important to vitality, as it delivers vitamin D. In fact, many experts believe a vitamin D deficiency exists in the United States, which results in significant morbidity.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">3</sup></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;">Fortunately only 1% of all UV light from the atmosphere reaches the retina.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">4</sup> Most is absorbed at the cornea and the lens, which essentially work as filters to prevent its penetration.</strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;">Furthermore, transmission of UV light through the lens decreases greatly with age.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">5</sup> For example, a 10-year-old has a 75% or greater lens transmission rate. By age 25, the transmission drops to 10%. It is remarkable that this change happens within such a short span of years, and the amount of UV light transmission only decreases as age increases. Specifically, 80% of all the damage patients experience may well happen before age 18.</strong></div> <h2 style="color: #1b4475; font-size: 12pt; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> <strong class="references" style="font-size: 8pt; text-align: left;">OCULAR DISEASES ASSOCIATED WITH UV EXPOSURE</strong></h2> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><b>* Photokeratitis:</b></i> Photokeratitis— more commonly known as "snow blindness"—is essentially an inflammation of the cornea secondary to UV exposure. The condition is much more likely to be found by practitioners who live in ski resort areas (such as in Colorado or Utah), as well as those who live near beaches (such as in California and Florida).</strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;">Photokeratitis is directly attributed to environmental UV radiation exposure and generally occurs eight to 24 hours after being in the sun. It is more typical in individuals who have not used sun protection, such as sunglasses or hats, or were exposed to significant UV radiation for long periods.</strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3q_tWEpehBSgjvRbQ_8qLBta0If0ykVB4AsF5fiDIUDTZu2D6DgqHE26gUvMKrqnWh2NNbB_Chs2iAkyyLMcXrPIt6a7hfoUmHuGXplgjpJrBa5FS1-ZOK-glSneStwtgVnQkNUSXR1I/s1600/fig2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3q_tWEpehBSgjvRbQ_8qLBta0If0ykVB4AsF5fiDIUDTZu2D6DgqHE26gUvMKrqnWh2NNbB_Chs2iAkyyLMcXrPIt6a7hfoUmHuGXplgjpJrBa5FS1-ZOK-glSneStwtgVnQkNUSXR1I/s1600/fig2.jpg" /></a></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Figure 2: Conjunctival intraepithelial neoplasm.</strong> </strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">The primary symptoms are similar to a welder's burn and include significant photophobia and pain. Patients may even have blepharospasm due to the level of photophobia. The cornea often shows signs of ocular surface disease damage, very similar to what you might see with an advanced dry eye disease patient. It is not uncommon to see filamentary keratitis, conjunctival injection and even significant superficial punctate keratopathy.</strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Patients are typically treated with a combination steroid/antibiotic agent, ample lubrication with preservative-free artificial tears, and are instructed to remain indoors with cool compresses.</strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><em style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><strong>* Climatic Droplet Keratopathy:</strong></em> Another very rare corneal disease due directly to UV exposure is a condition called climatic droplet keratopathy. This degeneration affects the stromal layer of the cornea. Due to the significant UV effects, particularly from UVB and UVC, an accumulation of droplet-like deposits occurs in the cornea. Further research shows that these are actually altered proteins, but they have an appearance that mimic that of droplets.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">6</sup></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Similar to photokeratitis, climatic droplet keratopathy tends to be a binocular condition. Unfortunately, this can also be sight threatening, as it can lead to scarring and opaci-fication of the cornea.</strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Treatment is very similar to that of photokeratitis and involves a combination of corticosteroids, cool compresses and artificial tears. The patient should also be monitored for the potential of neovascularization and, in rare cases, eventual conjunctivalization (i.e., invasion of conjunctival epithelial cells onto the corneal surface).</strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><b>* Pinguecula:</b></i> A more common condition due to UV exposure is pinguecula. This raised nodule appears on the conjunctiva, particularly around the limbal area, and is nasal or temporal in location. Pingueculae can become inflamed due to dryness or sun exposure. In fact, research shows that pingueculae are much more likely to be found in individuals who live in areas of greater sun exposure or dry air environments.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">7</sup></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">This combination suggests that this condition may be related to sun, but could also be related to dry eyes with irritation. Pingueculae are much more common in individuals who work or spend significant amounts of time outdoors.</strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Most commonly, patients with this condition have a cosmetic issue and at times may even get inflammation resulting in a pingue-culitis. Furthermore, patients with a pinguecula may have difficulty with contact lens wear, depending on the nodule's location.</strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><b>* Pterygium: </b></i>Another similar condition is that of a pterygium. In this example, the patient has a raised, wedge-shaped area of growth over the temporal aspect of the cornea with a lipid line suggesting an aggressive condition. The pterygium is differentiated tissue that is migrating into the corneal space. However, very similar to a pinguecula, these tend to be found in arid conditions or where significant UV exposure is noted, such as near the equator.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">7</sup></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><br /></sup></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> </div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">The significance of a pterygium is that it continues to migrate into the visual axis of the cornea, resulting in topographical changes or even scarring of the visual axis if it progresses. For this reason, once the initial changes are noted or it appears to be progressing rapidly, a conjunctival resection is required.</strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Unfortunately, most resections have a high recurrence rate, and newer techniques—such as the use of a Gunderson flap, mitomycin C application or even amniotic membrane transfer—often have to be utilized to prevent recurrence and scarring.</strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgC2u4-ZTrD9f8qzGD5B2o60yfHanMqswq_rCOphst1FFM_YguGnqHvkQA_gFNjoyIxiwtANWOQRh-hOPiMMEV0gma82pQUpM9APY_TZ3BMNB_nEoaTuLeUTcJwRFviMGBA8DfdNlqDFsc/s1600/fig3.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgC2u4-ZTrD9f8qzGD5B2o60yfHanMqswq_rCOphst1FFM_YguGnqHvkQA_gFNjoyIxiwtANWOQRh-hOPiMMEV0gma82pQUpM9APY_TZ3BMNB_nEoaTuLeUTcJwRFviMGBA8DfdNlqDFsc/s1600/fig3.jpg" /></a></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Figure 3: Early nuclear sclerotic cataract in a 58-year-old patient who admitted to excessive sun exposure over many years.</strong> </strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgg3k26TkfbvZky8osCQLdhXHfMGQE9NMxa_VmFx8-0r_TsSkrsziWER35J7HieJLAn4JlLleCx1D9cx2BbGqddrs3XEj638cM8vSNuHpq6zZfHosqPdpRGwAhwiVdhgVizS7vRSU-CBJw/s1600/fig4.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgg3k26TkfbvZky8osCQLdhXHfMGQE9NMxa_VmFx8-0r_TsSkrsziWER35J7HieJLAn4JlLleCx1D9cx2BbGqddrs3XEj638cM8vSNuHpq6zZfHosqPdpRGwAhwiVdhgVizS7vRSU-CBJw/s1600/fig4.jpg" /></a></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Figure 4: A 43-year-old patient with a sebaceous cell carcinoma.</strong> </strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"></strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><b>* Cataract:</b></i> One of the most common ocular conditions associated with UV exposure is cataract development. A crystalline lens is made up of proteins. These proteins can be altered or denatured by exposure to UVB or UVC radiation. In fact, all three layers of the lens— nucleus, cortex and capsule—can have alterations in their protein structures.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">8</sup></strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Depending on the location of the change, the type of cataract can range from nuclear sclerotic to cortical and others.</strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Once again, patients who live in high UV exposure areas, such as the equator, are more likely to have advanced cataract development. Although this is not too much of an issue in the United States, cataract is the leading cause of blindness in non-industrialized countries.</strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><b>* AMD. </b></i>Another condition highly associated with UV exposure is age-related macular degeneration (AMD). The worldwide prevalence rate of AMD resulting in impairment and blindness is 8.7%, making it one of the most common causes of blindness in patients over age 60. In the United States, for example, it is the number one cause of vision impairment in patients over age 50. Research suggests that AMD is the result of free radical damage.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">9 </sup>One of the more common reasons for free radical damage is exposure to ultraviolet radiation. Studies have shown that many individuals with macular degeneration have had greater UV exposure over their lifetime.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">10</sup></strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><b>* Solar Maculopathy: </b></i>Solar maculopathy results in a burn to the foveal area due to excessive exposure to UV light. Reports show that even 20 seconds of sun gazing may be enough to burn the macula in certain patients.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">11</sup> Of course, this can be an even shorter period of time if a person gazes at the sun during its zenith or uses binoculars or a telescope to watch a solar eclipse.</strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Damage associated with solar maculopathy is not reversible. It often mimics that of age-related macular degeneration, but of course it occurs in patients of any age who are not educated about the risks of solar gazing or staring at the sun. Unfortunately, most patients diagnosed with solar retinopathy or solar maculopathy tend to be those with mental disorders or patients with drug or alcohol abuse who do not have the understanding of the importance of not gazing directly at the sun.</strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">The term solar retinopathy is sometimes interchangeable with solar maculopathy, but includes peripheral vision loss. It is indeed possible for patients to have peripheral retinopathy due to sun gazing or significant UV exposure. Because there are no pain receptors in the retina, patients may be unaware of any significant exposure until it is too late and the damage is done. In cases of short duration exposure, damage may be temporary and have some reversal; but if patients gaze at the sun for significant periods of time, it is more often a permanent vision loss.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">12</sup></strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Patients with solar maculopathy present with a macula that typically shows retinal pigment epithelium (RPE) changes. There can also often be areas of hypopigmentation of the RPE at the fovea, which may show as hyperfluorescence on fluorescein angiography. Optical coherence tomography (OCT) will manifest an area of tissue loss or a punched-out lesion within an otherwise normal-thickness retina scan. This indicates the loss of the outer segments of the photoreceptors, as well as a loss of the inner portion of the hyperreflecting layer of the RPE.</strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhZD9IDlfnKJRkhEhMyBs7H3vZX3bjvGLe0GGmfOKvVh_2se2fctygjF8BNCTcWSrCjib82jhFVydlQlz2EttX0xL5YgLXjGBvccqoSQJDB4bfaTvjUPnilOykUUEQzcj6aMnU_zkLWm4U/s1600/fig5.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhZD9IDlfnKJRkhEhMyBs7H3vZX3bjvGLe0GGmfOKvVh_2se2fctygjF8BNCTcWSrCjib82jhFVydlQlz2EttX0xL5YgLXjGBvccqoSQJDB4bfaTvjUPnilOykUUEQzcj6aMnU_zkLWm4U/s1600/fig5.jpg" /></a></strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Figure 5: A patient presenting with madarosis and a diagnosis of a basal cell carcinoma.</strong> </strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"></strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Research suggests that the pathophysiology of solar maculopathy involves fragmentation and vesiculation of the photoreceptors of the rod and cone outer segment lamella, as well as pyknosis of the receptor nuclei.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">13</sup> However, because the cones are less likely to be affected, patients still may maintain relatively good vision. Even patients with significant solar maculopathy typically have vision of 20/50 to 20/70.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">13</sup></strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">The classic presentation of solar maculopathy is that of a brick red, well-defined lesion in the central fovea. In the very early stages of maculopathy, a small yellow-white spot, often surrounding a faint gray zone, is initially noted in the fovea. This may fade over one to two weeks, resulting in the classic, well-circumscribed brick red macular appearance.</strong></strong></strong></div> <h2 style="color: #1b4475; font-size: 12pt; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">UV LIGHT AND SKIN CANCER</strong></strong></strong></h2> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">In the last three decades, there have been more skin cancers diagnosed in the United States than all other cancers combined. In fact, 60% of all malignant melanomas are directly correlated to UV radiation, and 90% of squamous cell and basal cell carcinomas can be attributed to sun exposure.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">14</sup> The direct cost to treat non-melanoma cancers is approximately $1.5 billion per year and continues to rise at a 4% per year increase.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">14</sup></strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><b>* Sebaceous Cell Carcinoma: </b></i>The patient in <a href="http://www.revoptom.com/continuing_education/tabviewtest/lessonid/108520/#fig4" style="color: #003366; font-family: Tahoma, Arial, Helvetica, sans-serif; text-decoration: none;"><strong>Figure 4</strong></a> was a 43-year-old white male who had noted a lesion return to the left upper eyelid for the third time in the exact location. Close examination shows that the raised area of tissue mimics a potential chalazion. However, there is significant madarosis (missing eyelashes) and tissue displacement.</strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Given the appearance of the lesion, this certainly could be a chalazion; however, certain skin cancers, such as a sebaceous cell carcinoma, can mimic a chalazion in presentation. Patients with this type of presentation should be asked about sun exposure; this gentleman worked outdoors approximately 12 hours a day. In his case, the lesion was removed, a biopsy was conducted, and the biopsy results were positive for sebaceous cell carcinoma.</strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgRhSHuoEB-zNY1B5_4MS0Scot9DMJ9WuyeIvIZWKZ3l0AKiLj-kA1MaR7AJJf7dl-yoq5UmPrBT9Mzf0W6iQu-DmoNQqLEfgf3hpaMeo4eTeR6DeNKlPY6qAnsinANBIdCpyO9xMthuEg/s1600/fig6.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgRhSHuoEB-zNY1B5_4MS0Scot9DMJ9WuyeIvIZWKZ3l0AKiLj-kA1MaR7AJJf7dl-yoq5UmPrBT9Mzf0W6iQu-DmoNQqLEfgf3hpaMeo4eTeR6DeNKlPY6qAnsinANBIdCpyO9xMthuEg/s1600/fig6.jpg" /></a></strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Figure 6: A diagnosis of photokeratitis in a skiier.</strong> </strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"></strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Sebaceous cell carcinomas are relatively rare forms of skin cancer. However, optometrists can often be the ones to identify them because they usually originate in the meibomian glands. With time, they start to show alterations to skin tissue, typically madarosis.</strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">This type of cancer can be highly malignant, significantly infiltrative and may metastasize. In fact, the mortality rate for sebaceous cell carcinomas reaches 30% in the United States.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">15</sup> Surgical excision is the usual management; unfortunately, they are non-responsive to any further treatment.</strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><b>* Basal Cell Carcinoma:</b></i> A much more common type of cancer is basal cell carcinoma <i style="font-family: Tahoma, Arial, Helvetica, sans-serif;">[<a href="http://www.revoptom.com/continuing_education/tabviewtest/lessonid/108520/#fig5" style="color: #003366; text-decoration: none;"><strong>Figure 5</strong></a>]</i>; here, a different patient presents with madarosis. However, note that the lesion in this area is raised, with an umbilicated center and a glossy or pearly margin appearance. Also take note of the significantly large blood vessel, known as a feeder vessel, which is common in skin cancer presentations.</strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilB_iRlROGpRnM4U5svH7d8E9JfEBOVL1At0w1aZ2yiS52CrJrO4V6ZlBCjKAl457QuGpoJ6q7wd80PV6JVfkwZXMJ03aoj0IaoYLe9WRE8aPHoi8Uf_62wBAOt4eFLvx_MgHzE9-jDGI/s1600/fig7.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEilB_iRlROGpRnM4U5svH7d8E9JfEBOVL1At0w1aZ2yiS52CrJrO4V6ZlBCjKAl457QuGpoJ6q7wd80PV6JVfkwZXMJ03aoj0IaoYLe9WRE8aPHoi8Uf_62wBAOt4eFLvx_MgHzE9-jDGI/s1600/fig7.jpg" /></a></strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Figure 7: A young patient presenting with an advancing pterygium.</strong> </strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><br /></strong></strong></strong></div> <div class="separator" style="clear: both; text-align: center;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"></strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">The most common complaints of patients with basal cell carcinoma are cosmetic changes and loss of lashes, as well as persistent scabbing or crusting, and bleeding. Optometry once again may be well positioned to make the diagnosis of basal cell carcinoma. This type of skin cancer is 10 times more common than any other form of skin cancer and is often found on the eyelid margins or even the caruncle region.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">16</sup> Other common locations are the inner nose area as well as behind the ears.</strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><b>* Malignant Melanoma: </b></i>This is another form of skin cancer often observed by optometrists. Malignant melanomas can appear in the choroid, the iris or even the conjunctiva. Malignant means that the tumor has the potential to metastasize. Melanoma shows that it arises from the pigmented cells of the eye. Because the choroid has the highest blood flow of any structure in the body and is considered part of the uveal tract, which also includes the iris and sclera, these tumors can often be aggressive. In fact, malignant melanomas of the choroid are the most common intraocular malignancy present.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">17</sup></strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><br /></sup></strong></strong></strong></div> <div style="font-size: 13px; font-weight: normal; margin-bottom: 12px;"> </div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Patients with a choroidal nevus are much more likely to develop a malignant melanoma. The difference between a benign choroidal nevus and a malignant melanoma is that nevi are typically smaller in size and flat (or non-elevated). A malignant melanoma, on the other hand, often has significant elevation, associated retinal detachment, and often presents in an overlying finding known as lipofuscin. It is also significantly larger and, depending on the location, may result in a change in refractive error or visual disturbance.</strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Malignant melanomas are life threatening because of their high predisposition to metastasis. They most commonly spread to the lungs, but also to the liver, GI tract and other areas of the skin. The diagnosis of malignant melanoma requires a prompt referral to a primary physician or an oncologist.</strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Malignant melanoma of the ocular surface also stems from the presence of melanin or pigment that is present on the conjunctiva. The presence of unilateral melanosis increases the malignancy potential. However, the incidence of melanonoma is only one in 400.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">18</sup></strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Melanosis can range from congenital findings that may involve pigment flecks, usually near the limbus, or it can be significant, such as that of nevus of Ota. Melanosis typically does not change with time and tends to be relatively small. Large areas of pigment or melanin accumulation raise concern for a potential malignant melanoma.</strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Greater concern is warranted if it is found in the upper tarsal plate of the conjunctiva or the lower fornix.</strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Perhaps the most common area for malignant melanoma is on the skin tissue; many times this is found on other sun-exposed areas near the eye or even the forehead, and is brought up by patients. Follow the ABCDE rule to help determine if a lesion of the skin could be a malignant melanoma (<i style="font-family: Tahoma, Arial, Helvetica, sans-serif;">See sidebar: <a href="http://www.revoptom.com/continuing_education/tabviewtest/lessonid/108520/#abc" style="color: #003366; text-decoration: none;"><strong>Know Your ABCDEs</strong></a></i>).</strong></strong></strong></div> <h2 style="color: #1b4475; font-size: 12pt; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">UV RADIATION AND SPECTACLE LENSES</strong></strong></strong></h2> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Most patients and clinicians think that photochromic lenses, polarized lenses, sunglasses and tinted lenses block 100% of ultraviolet A and B radiation. Although that is typically true with direct transmission, it does not account for exposure due to reflected light. In other words, light that reflects off the back surface of a lens—including sunglasses, polarized and any spectacle lens—can still allow significant ultraviolet light to enter the eyes.</strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Furthermore, anti-reflective coatings, which are often applied to many of these types of lenses, may actually increase ultraviolet light radiation exposure to the eyes and skin around the eye area.</strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Dermatological exposure to UV light is highest between the peak times of 10 a.m. to 2 p.m. But, surprisingly, the most significant ocular exposure to UV light does not occur during this time frame. It actually occurs when the light hits at an angle, thus reflecting off the back surface of the lens and entering into the eye. These times are typically between 8 to 10 a.m. and between 2 to 4 p.m.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">19</sup></strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Furthermore, these are times when patients are not typically wearing sunglasses. Research shows that 40% of the annual exposure occurs during these non-peak times into the eye.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">19</sup> To add insult to injury, 23% of people never wear eye protection and only 6% of Americans know they need sun protection for their eyes.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">20</sup></strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><br /></sup></strong></strong></strong></div> <div style="margin-bottom: 12px;"> </div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">To make matters worse, the human skull and orbital configuration is designed to allow a large temporal field of vision. So, this large field of vision also allows for significant light from side exposure. This is known as peripheral light focusing radiation or the Coroneo effect.21 Light reaches the peripheral cornea or limbus as much as 20 times greater than other locations.</strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Furthermore, the limbus is associated with the uvea and is one of the most sensitive areas of the eye.</strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">These zones of blue, blue-violet and UV light have been shown to be damaging to the ocular surface. So, depending on the geometry of the lens, the frame and environmental conditions, an average of 20% of this light (although the range is 10% to 50%) comes from the back and sides of the lens.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">22</sup></strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Certain environmental conditions can have extreme UV exposure from the sides and back surface of the spectacle lenses. For example, snow reflectance transmits 94% of UVA light and 88% of UVB light.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">23</sup></strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Clear lenses reflect 4% to 6% of UV radiation, while no-glare or an-tireflective lenses actually increase this reflectance to 25% of UV light radiation on average.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">22</sup> Some types of lenses reflect up to 90% of the most damaging short wavelength lights, including UV and blue light transmission.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">22 </sup>So, although UV light protection is found on the front coatings of many lenses, it does not account for back surface reflection.</strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">New technologies, such as Crizal lenses, can now eliminate backside UV radiation reflection and particularly focus on the shorter wavelength light, including UVB and UVC. Specifically, Crizal Sapphire UV and Crizal UV Avancé, which came out earlier this year, provide full-spectrum blocking technology on both the front and back surfaces.</strong></strong></strong></div> <div style="margin-bottom: 12px;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><em style="font-family: Tahoma, Arial, Helvetica, sans-serif;">Dr. Karpecki serves as corneal services and ocular disease research director at Koffl er Vision Group in Lexington, Ky., and heads its ocular surface disease clinic. </em></strong></strong></strong></div> <h2 style="color: #1b4475; font-size: 12pt; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> <strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">REFERENCES</strong></strong></strong></h2> <ol class="references" style="font-size: 8pt;"> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: decimal;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;"><strong class="references" style="font-size: 8pt; text-align: left;">Pfeifer GP, You YH, Besaratinia A. 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El papel de los rayos UV en la enfermedad ocular

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La toronja puede entrar en conflicto con algunos fármacos y causar muerte súbita

<div dir="ltr" style="text-align: left;" trbidi="on"> Visualizacion optima 1600x900 pixel Comenta.esta.publicación<br /> <br /> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjZ16SGUYX3TVCUpNY14mo5jGiwEKHbMwkdJHf2Bk0uc344rVWt7eGLomhq5wfZhNgovbPL36HYC8r9_grI18hCwXMEMydRcn1XQt32tw_TqdIN6exWfaDCeixPrysjlS0vEh5VMldv4Y/s1600/Toronja.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="426" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjZ16SGUYX3TVCUpNY14mo5jGiwEKHbMwkdJHf2Bk0uc344rVWt7eGLomhq5wfZhNgovbPL36HYC8r9_grI18hCwXMEMydRcn1XQt32tw_TqdIN6exWfaDCeixPrysjlS0vEh5VMldv4Y/s640/Toronja.jpg" width="640" /></a></div> <br /> <span style="background-color: white; color: #333333; font-family: arial;">El número de fármacos que resultan altamente peligrosos al ser mezclados con toronja se saltó de 17 a 43 en los últimos cuatro años, advirtió un investigador canadiense. En un artículo publicado en el “Canadian Medical Association Journal”, David Bailey del Lawson Health Research Institute de Londres (Ontario) dijo que el conflicto </span><b style="background-color: white; border: 0px; color: #333333; font-family: arial; margin: 0px; outline: 0px; padding: 0px;">se produce con más de 85 medicamentos como anticancerígenos, para el corazón, analgésicos y otros más para el tratamiento de la esquizofrenia</b><span style="background-color: white; color: #333333; font-family: arial;">. ¿Qué es lo que sucede? La fruta contiene</span><b style="background-color: white; border: 0px; color: #333333; font-family: arial; margin: 0px; outline: 0px; padding: 0px;">furanocoumarinas </b><span style="background-color: white; color: #333333; font-family: arial;">como ingrediente activo. Este, cuando se mezcla con determinados fármacos, </span><b style="background-color: white; border: 0px; color: #333333; font-family: arial; margin: 0px; outline: 0px; padding: 0px;">inhibe la enzima CYP34A</b><span style="background-color: white; color: #333333; font-family: arial;"> y, como consecuencia,</span><b style="background-color: white; border: 0px; color: #333333; font-family: arial; margin: 0px; outline: 0px; padding: 0px;"> los medicamentos entran en el torrente sanguíneo con tal potencia que puede conducir a una sobredosis</b><span style="background-color: white; color: #333333; font-family: arial;">. No se necesita comer mucha toronja para que se produzca esta asociación. De hecho, beber un vaso de jugo de toronja con la medicación puede causar efectos secundarios graves, como una hemorragia gastrointestinal, insuficiencia renal, problemas respiratorios y hasta muerte súbita.</span><br /> <span style="background-color: white; color: #333333; font-family: arial;"><br /></span> <br /> <div style="background-color: white; border: 0px; color: #333333; font-family: arial; line-height: 16px; margin-bottom: 15px; outline: 0px; padding: 0px;"> Estos son los medicamentos que deben evitarse consumir junto con toronja:</div> <div style="background-color: white; border: 0px; color: #333333; font-family: arial; line-height: 16px; margin-bottom: 15px; outline: 0px; padding: 0px;"> </div> <ul style="background-color: white; border: 0px; color: #333333; font-family: arial; list-style: none; margin: 0px; outline: 0px; padding: 0px;"> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">amiodarone (Cordarone)8</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">astemizole (Hismanal)5, 9</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">atorvastatin (Lipitor)</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">budesonide (Entocort)8</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">buspirone (BuSpar)</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">cerivastatin (Baycol)5, 9</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">cilostazol (Pletal)5</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">cisapride (Propulsid, Prepulsid)9</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">colchicine5</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">eletriptan (Relpax)5</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">etoposide (Vepesid)8, 10</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">halofantrine (Halfan)</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">lovastatin (Mevacor)</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">mifepristone (Mifeprex)5</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">pimozide (Orap)5</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">quinidine (Quinaglute,</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">Quinidex)8, 10</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">sildenafil (Viagra)</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">simvastatin (Zocor)8</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">sirolimus (Rapamune)1, 5</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">terfenadine (Seldane)9</li> <li style="border: 0px; margin: 0px; outline: 0px; padding: 0px;">ziprasidone (Geodon)5</li> </ul> <div> <span style="color: #333333; font-family: arial;"><br /></span></div> <div> <span style="color: #333333; font-family: arial;"><br /></span></div> <div> <span style="color: #333333; font-family: arial;"><div> Drug Interactions with Grapefruit and Related Citrus Fruits Excerpted from Food-Medication Interactions 14 th  Edition </div> <div> <br /></div> </span></div> <div> <span style="color: #333333; font-family: arial;"><div style="text-align: justify;"> Many drugs interact with grapefruit (juice, segments, extract and certain related citrus fruits, e.g. Seville  oranges, pummelos, and some exotic orange varieties). Several components in grapefruit called furanocoumarins (two of the most common are bergamottin and 6’7’-dihydroxybergamottin) irreversibly inhibit cytochrome P450 3A4 isoenzymes (3A4) in the intestinal wall, decreasing the pre-systemic metabolism of affected drugs taken up to 72 hours after grapefruit consumption. Intestinal 3A4 activity can remain inhibited during this time, as the body produces more enzymes. Greater amounts of 3A4-metabolized drugs can then enter the systemic circulation. The resulting increase in drug levels can lead to an increase in therapeutic </div> <div style="text-align: justify;"> effect, adverse effects and/or toxicity. Interactions are most pronounced for drugs that normally undergo a large amount of pre-systemic metabolism (low oral bioavailability). Limited evidence indicates that following intake of very large amounts of grapefruit, hepatic 3A4 may also be inhibited.  If a drug’s metabolic pathways are known, it may be possible to predict if an interaction with grapefruit could occur. Grapefruit weakly inhibits intestinal cell wall p-glycoprotein (p-GP), an efflux pump in enterocytes that actively secretes some absorbed drugs back into the gut lumen. Not all 3A4-metabolized drugs are p-GP substrates. Organic anion transporting polypeptide (OATP) is another transporter system affected by grapefruit. Drugs handled by OATP may have  decreased absorption when taken with grapefruit, possibly </div> <div style="text-align: justify;"> leading to loss of efficacy. Emerging information indicates bergamottin inactivates cytochrome p450 2B6 and 3A5 isoenzymes, potentially causing drug interactions with substrates of these isoenzymes.</div> <div style="text-align: justify;"> <br /></div> <div style="text-align: justify;"> Medications that should be avoided with grapefruit </div> <div style="text-align: justify;"> <br /></div> <div style="text-align: justify;"> <div> amiodarone (Cordarone)8</div> <div> astemizole (Hismanal)5, 9</div> <div> atorvastatin (Lipitor)</div> <div> budesonide (Entocort)8</div> <div> buspirone (BuSpar)</div> <div> cerivastatin (Baycol)5, 9</div> <div> cilostazol (Pletal)5</div> <div> <div> cisapride (Propulsid, Prepulsid)9</div> <div> colchicine5</div> <div> eletriptan (Relpax)5</div> <div> etoposide (Vepesid)8, 10</div> <div> halofantrine (Halfan) </div> <div> lovastatin (Mevacor) </div> <div> mifepristone (Mifeprex)5</div> </div> <div> <div> pimozide (Orap)5</div> <div> quinidine (Quinaglute, </div> <div> Quinidex)8, 10</div> <div> sildenafil (Viagra) </div> <div> simvastatin (Zocor)8</div> <div> sirolimus (Rapamune)1, 5 </div> <div> terfenadine (Seldane)9 </div> <div> ziprasidone (Geodon)5 </div> </div> <div> <br /></div> <div> <br /></div> <div> Use with grapefruit with caution </div> <div> <br /></div> <div> <br /></div> <div> <div> albendazole (Albenza) </div> <div> alfentanil (Alfenta)8 </div> <div> alfuzosin (Uroxatral)5 </div> <div> almotriptan (Axert) 5 </div> <div> aprepitant (Emend)5 </div> <div> aripiprazole (Abilify) 5 </div> <div> bupropion (Wellbutrin, Zyban)5 </div> <div> carbamazepine (Tegretol)3 </div> <div> cinacalcet (Sensipar)5 </div> <div> clomipramine (Anafranil) </div> <div> cyclosporine (Neoral)2, 3, 8 </div> <div> darifenacin (Enablex)5 </div> <div> delavirdine (Rescriptor)5 </div> <div> dextromethorphan </div> <div> diazepam (Valium)8 </div> <div> dofetilide (Tikosyn)5 </div> <div> efavirenz (Sustiva)5 </div> <div> erlotinib (Tarceva)5 </div> <div> erythromycin (Eryc, E-mycin,  </div> <div>   Erythromid, Erybid)8 </div> <div> eszopiclone (Lunesta)5 </div> <div> felodipine (Renedil, Plendil) </div> <div> fexofenadine (Allegra)10 </div> <div> fluvoxamine (Luvox) </div> <div> gefitinib (Iressa)5 </div> <div> imatinib mesylate (Gleevec/Glivec)5 </div> <div> indinavir (Crixivan)10 </div> <div> itraconazole (Sporanox)10 </div> <div> losartan (Cozaar) </div> <div> methadone (Dolophine)5 </div> <div> methylprednisolone (Medrol)8 </div> <div> midazolam (Versed)8 </div> <div> montelukast (Singulair)5 </div> <div> nicardipine (Cardene)8 </div> <div> nifedipine (Procardia) </div> <div> nimodipine (Nimotop) </div> <div> nisoldipine (Sular) </div> <div> oxybutynin (Ditropan)5 </div> <div> propafenone (Rythmol)5, 11 </div> <div> quetiapine fumarate (Seroquel)5 </div> <div> quinine </div> <div> ramelteon (Rozerem)5 </div> <div> saquinavir (Invirase)2 </div> <div> sertraline (Zoloft) </div> <div> solifenacin (Vesicare)5 </div> <div> tacrolimus (Prograf)2, 3, 8 </div> <div> tamoxifen (Nolvadex)5 </div> <div> tamsulosin (Flomax)5 </div> <div> tolterodine (Detrol)5 </div> <div> triazolam (Halcion) </div> <div> trazodone (Desyrel)5 </div> </div> <div> <br /></div> <div> Medications with no significant interaction with grapefruit</div> <div> <br /></div> <div> <div> acebutolol (Monitan, Sectral)4 </div> <div> alprazolam (Xanax)4 </div> <div> amlodipine (Norvasc)4 </div> <div> amprenavir (Agenerase)4, 10 </div> <div> caffeine4, 8 </div> <div> carvedilol (Coreg)4 </div> <div> clarithromycin (Biaxin) </div> <div> clozapine (Clozaril)4 </div> <div> digoxin (Lanoxin)8 </div> <div> diltiazem (Cardizem)4, 8 </div> <div> eplerenone (Inspra)4 </div> <div> ethinyl estradiol4, 8 </div> <div> fentanyl (Actiq)4, 8 </div> <div> haloperidol (Haldol)8 </div> <div> lansoprazole (Prevacid)4, 8 </div> <div> levothyroxine (Eltroxin, </div> <div>   Synthroid)4, 8 </div> <div> omeprazole (Losec, </div> <div> Prilosec)4 </div> <div> phenytoin (Dilantin)8 </div> <div> pravastatin (Pravachol) </div> <div> prednisone (Deltasone) </div> <div> scopolamine (Hyoscine)4, 8 </div> <div> 17-β estradiol4, 8 </div> <div> telithromycin (Ketek)4 </div> <div> theophylline (Theo-Dur, </div> <div>   Uniphyl) </div> <div> verapamil (Calan, Isoptin, </div> <div>   Verelan)8 </div> <div> warfarin (Coumadin)8</div> </div> <div> <br /></div> <div> <br /></div> </div> </span></div> <ul style="background-color: white; border: 0px; color: #333333; font-family: arial; font-size: 12px; list-style: none; margin: 0px; outline: 0px; padding: 0px;"> <li></li> </ul> <span style="background-color: white; color: #333333; font-family: arial; font-size: 12px;"></span></div>

La toronja puede entrar en conflicto con algunos fármacos y causar muerte súbita

Visualizacion optima 1600x900 pixel Comenta.esta.publicación El número de fármacos que resultan altamente peligrosos al ser mezclados ...

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HALLOWEEN HAZARDS: THINK TWICE BEFORE TRANSFORMING YOUR EYES

<div dir="ltr" style="text-align: left;" trbidi="on"> Visualizacion optima 1600x900 pixel Comenta.esta.publicación<br /> <br /> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj0EVbL-2Ib5HWL8XLM7RuDF-K3mhl8w9NGQjMlYERijr912oWXexeQIjU8HUpqrv_c8w0KfOxOUtOqpVJ-6O8SUDO-TU_0VJ6QD0vXvfXuflqSYhttTUcaS1s2QupQxulZ6Ysm6kIUprg/s1600/logobig.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="92" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj0EVbL-2Ib5HWL8XLM7RuDF-K3mhl8w9NGQjMlYERijr912oWXexeQIjU8HUpqrv_c8w0KfOxOUtOqpVJ-6O8SUDO-TU_0VJ6QD0vXvfXuflqSYhttTUcaS1s2QupQxulZ6Ysm6kIUprg/s320/logobig.gif" width="320" /></a></div> <br /> <br /> <br /> <div align="center" style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12px; line-height: 1.5em;"> <strong><em>The American Optometric Association warns consumers: over-the-counter decorative contact lenses are illegal and may cause serious eye infections and possibly permanent vision loss</em></strong></div> <div align="center" style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12px; line-height: 1.5em;"> <strong><em><br /></em></strong></div> <div align="center" style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 12px; line-height: 1.5em;"> <strong><em><br /></em></strong></div> <strong style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> <strong>ST. LOUIS, MO, Oct. 9, 2012</strong> - Halloween is a fun holiday, but playing dress up can be serious business.  Consumers spend hours making sure costumes are accessorized just right; however, transforming your eyes by changing their color or appearance with non-corrective, decorative contact lenses to look like a cat, werewolf or vampire can be a dangerous choice.  The American Optometric Association (AOA) is warning consumers about the risks of wearing decorative contact lenses sold illegally, without a prescription from an eye doctor. </div> </strong><div style="text-align: justify;"> <span style="font-family: Verdana, Arial, Helvetica, sans-serif;"><br /></span></div> <span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> According to the AOA's 2012 American Eye-Q® consumer survey, 18 percent of Americans wear these non-corrective, decorative or colored contact lenses. Of those, 28 percent report illegally purchasing the lenses without a prescription and from a source other than an eye doctor, a great concern to doctors of optometry.</div> </span><div style="text-align: justify;"> <span style="font-family: Verdana, Arial, Helvetica, sans-serif;"><br /></span></div> <span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> "There is no such thing as a 'one size fits all' contact lens," said Dr. Randall Fuerst, chair of the AOA's Contact Lens & Cornea Section.  "Consumers who purchase lenses illegally, without a prescription or without consultation from an eye doctor, put themselves at risk for serious bacterial infections, allergic reactions, or even significant damage to the eye's ability to function, with the potential for irreversible sight loss."</div> </span><div style="text-align: justify;"> <span style="font-family: Verdana, Arial, Helvetica, sans-serif;"><br /></span></div> <span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> A proper medical eye and vision examination ensures that the individual is a viable candidate for contact lens wear, that the lenses are properly fitted and that the patient is able to safely care for their lenses.  </div> </span><div style="text-align: justify;"> <span style="font-family: Verdana, Arial, Helvetica, sans-serif;"><br /></span></div> <span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> Since 2005, federal law requires the Food and Drug Administration (FDA) to regulate decorative lenses as medical devices, similar to prescription contact lenses.  However, decorative lenses continue to be illegally marketed and distributed directly to consumers through a variety of sources, including flea markets, the Internet, beauty salons and convenience stores. Consumers also report purchasing them at retail outlets, where they are sold as fashion accessories. </div> </span><div style="text-align: justify;"> <span style="font-family: Verdana, Arial, Helvetica, sans-serif;"><br /></span></div> <span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> "Decorative contact lenses carry the same risks as corrective contact lenses," said Dr. Fuerst.  "Because of this, it's important for consumers to obtain a prescription and familiarize themselves with the information available from an eye doctor to reduce the risk of infection.</div> </span><div style="text-align: justify;"> <span style="font-family: Verdana, Arial, Helvetica, sans-serif;"><br /></span></div> <span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> The AOA offers the following recommendations for all contact lens wearers:</div> </span><ul style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"> <li style="line-height: 1.5em; margin-bottom: 10px; text-align: justify;">Wear contact lenses only if they are fitted and prescribed by an optometrist.</li> <li style="line-height: 1.5em; margin-bottom: 10px; text-align: justify;">Do not purchase contact lenses from gas stations, video stores, or any other vendor not authorized by law to dispense contact lenses.</li> <li style="line-height: 1.5em; margin-bottom: 10px; text-align: justify;">Never swim while wearing contact lenses. There is a risk of eye infection when contact lenses come into contact with bacteria in swimming pool water.</li> <li style="line-height: 1.5em; margin-bottom: 10px; text-align: justify;">Make sure contact lenses are properly cleaned and disinfected as instructed by your eye-care professional.</li> <li style="line-height: 1.5em; margin-bottom: 10px; text-align: justify;">Make sure you wash your hands before handling and cleaning your contact lenses.</li> <li style="line-height: 1.5em; margin-bottom: 10px; text-align: justify;">Never swap or share contact lenses with anyone.</li> <li style="line-height: 1.5em; margin-bottom: 10px; text-align: justify;">Never sleep while wearing contact lenses unless they are extended-wear lenses specifically designed for that purpose.</li> </ul> <div style="text-align: justify;"> <span style="font-family: Verdana, Arial, Helvetica, sans-serif;"><br /></span></div> <div> <div style="text-align: justify;"> <span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;">About the American Eye-Q® survey:</span></div> <span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> The seventh annual American Eye-Q® survey was created and commissioned in conjunction with Penn, Schoen & Berland Associates (PSB). From May 9 - 16, 2012, using an online methodology, PSB conducted 1,009 online interviews among Americans 18 years and older who embodied a nationally representative sample of U.S. general population. (Margin of error at 95 percent confidence level)</div> </span><div style="text-align: justify;"> <span style="font-family: Verdana, Arial, Helvetica, sans-serif;"><br /></span></div> <span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> About the American Optometric Association (AOA):</div> </span><span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> The American Optometric Association represents approximately 36,000 doctors of optometry, optometry students and paraoptometric assistants and technicians. Optometrists serve patients in nearly 6,500 communities across the country, and in 3,500 of those communities are the only eye doctors.  Doctors of optometry provide two-thirds of all primary eye care in the United States.</div> </span><div style="text-align: justify;"> <span style="font-family: Verdana, Arial, Helvetica, sans-serif;"><br /></span></div> <span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> Doctors of optometry (ODs) are the independent primary health care professionals for the eye. Optometrists examine, diagnose, treat, and manage diseases, injuries, and disorders of the visual system, the eye, and associated structures as well as identify related systemic conditions affecting the eye.</div> </span><div style="text-align: justify;"> <span style="font-family: Verdana, Arial, Helvetica, sans-serif;"><br /></span></div> <span style="background-color: white; font-family: Verdana, Arial, Helvetica, sans-serif;"><div style="text-align: justify;"> Prior to optometry school, optometrists typically complete four years of undergraduate study, culminating in a bachelor's degree. Required undergraduate coursework for pre-optometry students is extensive and covers a wide variety of advanced health, science and mathematics. Optometry school consists of four years of post-graduate, doctoral study concentrating on both the eye and systemic health. In addition to their formal training, doctors of optometry must undergo annual continuing education to stay current on the latest standards of care. For more information, visit www.aoa.org.</div> </span></div> </div>

HALLOWEEN HAZARDS: THINK TWICE BEFORE TRANSFORMING YOUR EYES

Visualizacion optima 1600x900 pixel Comenta.esta.publicación The American Optometric Association warns consumers: over-the-counter ...

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1RA SESION EXTRAORDINARIA Y DESCENTRALIZADA

<div dir="ltr" style="text-align: left;" trbidi="on"> Visualizacion optima 1600x900 pixel Comenta.esta.publicación<br /> <br /> <br /> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgamPLDZ2FiFsfI8Ten2yFFPO-Ek_bBuLhTO9Mg7-aJUn6QqO_1EWxFqFJSAQo2irJQ6blt3MN0FWKsAkUmlXt87lNp65l-sbDqqKT6VFz96LdE0-3p_FWYK28MXxCZnPQXGoChowbhciQ/s1600/123.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="640" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgamPLDZ2FiFsfI8Ten2yFFPO-Ek_bBuLhTO9Mg7-aJUn6QqO_1EWxFqFJSAQo2irJQ6blt3MN0FWKsAkUmlXt87lNp65l-sbDqqKT6VFz96LdE0-3p_FWYK28MXxCZnPQXGoChowbhciQ/s640/123.jpg" width="460" /></a></div> <br /></div>

1RA SESION EXTRAORDINARIA Y DESCENTRALIZADA

Visualizacion optima 1600x900 pixel Comenta.esta.publicación

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Lente escleral de hoy

<div dir="ltr" style="text-align: left;" trbidi="on"> <br /> <div class="ceintro" style="background-color: #fefefd; color: #333333; margin-bottom: 12px;"> </div> <div class="ceintro" style="margin: 0cm 0cm 9pt;"> </div> <div class="ceintro" style="font-family: Arial, Helvetica, sans-serif; margin: 0cm 0cm 9pt;"> <span style="font-family: Tahoma;">Lentes esclerales son ya universales - se utiliza no sólo para los pacientes córnea irregular, pero también para el tratamiento de errores de refracción alto y la presbicia.</span><span style="font-family: Arial;"><o:p></o:p></span></div> <div class="ceauthor" style="font-family: Arial, Helvetica, sans-serif; margin: 0cm 0cm 9pt;"> <i><span style="font-family: Tahoma;">Por Gregory W. DeNaeyer, OD</span></i><i><span style="font-family: Arial;"><o:p></o:p></span></i></div> <div class="MsoNormal" style="font-family: Arial, Helvetica, sans-serif;"> <span style="font-family: Tahoma; text-transform: uppercase;">FECHA DE PUBLICACIÓN: JUNIO </span><span style="font-family: 'Arial Unicode MS'; text-transform: uppercase;">​​</span><span style="font-family: Tahoma; text-transform: uppercase;">DE 2012</span><span style="font-family: Arial; text-transform: uppercase;"><o:p></o:p></span></div> <div class="MsoNormal" style="font-family: Arial, Helvetica, sans-serif;"> <span style="font-family: Tahoma; text-transform: uppercase;">FECHA DE VENCIMIENTO: 01 DE JUNIO 2015</span><span style="font-family: Arial; text-transform: uppercase;"><o:p></o:p></span></div> <h2 style="font-family: Arial, Helvetica, sans-serif; margin: 11.25pt 0cm 1.5pt;"> <span style="font-size: small; font-weight: normal;"><span style="color: #1b4475; font-family: Tahoma; text-transform: uppercase;">OBJETIVO DECLARACIÓN:</span><span style="color: #1b4475; font-family: Arial; text-transform: uppercase;"><o:p></o:p></span></span></h2> <div style="font-family: Arial, Helvetica, sans-serif; margin: 0cm 0cm 9pt;"> <span style="font-family: Tahoma;">En este artículo se presentará una actualización de las lentes esclerales actuales y delinear su capacidad para tratar a pacientes con la córnea irregular, los errores de refracción alto y presbicia.</span><span style="font-family: Arial;"><o:p></o:p></span></div> <h2 style="font-family: Arial, Helvetica, sans-serif; margin: 11.25pt 0cm 1.5pt;"> <span style="font-size: small; font-weight: normal;"><span style="color: #1b4475; font-family: Tahoma; text-transform: uppercase;">FACULTAD / EDITORIAL BOARD:</span><span style="color: #1b4475; font-family: Arial; text-transform: uppercase;"><o:p></o:p></span></span></h2> <div style="font-family: Arial, Helvetica, sans-serif; margin: 0cm 0cm 9pt;"> <span style="font-family: Tahoma;">Greg W. DeNaeyer, OD</span><span style="font-family: Arial;"><o:p></o:p></span></div> <h2 style="font-family: Arial, Helvetica, sans-serif; margin: 11.25pt 0cm 1.5pt;"> <span style="font-size: small; font-weight: normal;"><span style="color: #1b4475; font-family: Tahoma; text-transform: uppercase;">CRÉDITO DECLARACIÓN:</span><span style="color: #1b4475; font-family: Arial; text-transform: uppercase;"><o:p></o:p></span></span></h2> <div style="font-family: Arial, Helvetica, sans-serif; margin: 0cm 0cm 9pt;"> <span style="font-family: Tahoma;">Este curso está aprobado por la COPE durante 1 hora de crédito CE.<span class="apple-converted-space"> </span>COPE ID es 34757-CL.<span class="apple-converted-space"> </span>Por favor, compruebe su junta estatal de licencias para ver si esta aprobación cuenta para sus requisitos CE para relicencia.</span><span style="font-family: Arial;"><o:p></o:p></span></div> <h2 style="font-family: Arial, Helvetica, sans-serif; margin: 11.25pt 0cm 1.5pt;"> <span style="font-size: small; font-weight: normal;"><span style="color: #1b4475; font-family: Tahoma; text-transform: uppercase;">JOINT-SPONSORSHIP STATEMENT:</span><span style="color: #1b4475; font-family: Arial; text-transform: uppercase;"><o:p></o:p></span></span></h2> <div style="font-family: Arial, Helvetica, sans-serif; margin: 0cm 0cm 9pt;"> <span style="font-family: Tahoma;">Este curso de formación continua es conjunta patrocinada por el Colegio de Optometría de Pennsylvania.</span><span style="font-family: Arial;"><o:p></o:p></span></div> <h2 style="font-family: Arial, Helvetica, sans-serif; margin: 11.25pt 0cm 1.5pt;"> <span style="font-size: small; font-weight: normal;"><span style="color: #1b4475; font-family: Tahoma; text-transform: uppercase;">DISCLOSURE STATEMENT:</span><span style="color: #1b4475; font-family: Arial; text-transform: uppercase;"><o:p></o:p></span></span></h2> <div style="font-family: Arial, Helvetica, sans-serif; margin: 0cm 0cm 9pt;"> <span style="font-family: Tahoma;">El autor no tiene ninguna relación financiera a revelar.</span><span style="font-family: Arial;"><o:p></o:p></span></div> <div class="MsoNormal" style="font-family: Arial, Helvetica, sans-serif;"> <hr align="left" color="dimgray" noshade="" size="1" width="100%" /> </div> <div style="font-family: Arial, Helvetica, sans-serif; margin: 0cm 0cm 9pt;"> <span style="font-family: Tahoma;">El reciente resurgimiento de las lentes de contacto esclerales ha mejorado significativamente nuestro éxito en el manejo de pacientes con irregularidad corneal y la enfermedad de la superficie ocular (OSD). 1-4Paciente y la demanda profesional de las lentes de contacto esclerales ha llevado a los fabricantes a mejorar los productos existentes y desarrollar nuevos diseños. Los nuevos<o:p></o:p></span></div> <div style="font-family: Arial, Helvetica, sans-serif; margin: 0cm 0cm 9pt;"> <span style="font-family: Tahoma;">materiales y las soluciones también han contribuido a mejorar el éxito de las lentes de contacto esclerales.</span><span style="font-family: Arial;"><o:p></o:p></span></div> <div style="font-family: Arial, Helvetica, sans-serif; margin: 0cm 0cm 9pt;"> <span style="font-family: Tahoma;">En este artículo revisaremos las últimas actualizaciones en los materiales, soluciones, diseños y técnicas de montaje que se seguirán para promover el éxito de las lentes esclerales.</span><span style="font-family: Arial; font-size: 10pt; font-weight: bold;"><o:p></o:p></span></div> <div style="font-family: Arial, Helvetica, sans-serif; font-weight: bold; margin: 0cm 0cm 9pt;"> <span style="font-family: Tahoma;"><br /></span></div> <div style="margin: 0cm 0cm 9pt;"> </div> <h2 style="color: #1b4475; font-family: Arial, Helvetica, sans-serif; font-weight: bold; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> <span style="font-size: small;">CLASSIFICATION</span></h2> <div style="font-family: Arial, Helvetica, sans-serif; font-weight: normal; margin-bottom: 12px;"> The fitting characteristics and functionality of gas-permeable (GP) lenses are directly related to their diameter. Therefore, it's critical that a universal classification system be employed so that practitioners can use designs that have predictive characteristics. The Scleral Lens Education Society (SLS) has recently designed a classification system that defines GP lenses on both size and fitting characteristics (<i style="font-family: Tahoma, Arial, Helvetica, sans-serif;">see "<strong><a href="http://www.revoptom.com/continuing_education/tabviewtest/lessonid/108308/#terminology" style="color: #003366; text-decoration: initial;">Terminology</a></strong>"</i>):<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">5,6</sup></div> <ul style="font-family: Arial, Helvetica, sans-serif; font-weight: normal; list-style-type: square;"> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: square;"><i><b>Corneal lenses</b></i> (8mm to 12.5mm) are supported completely by the cornea. Corneal contact lenses do not hold a tear reservoir.</li> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: square;"><i><b>Corneal-scleral lenses</b></i> (12.5mm to 15mm) extend beyond the limbus, and are supported by both corneal and scleral tissue. Corneal-scleral lenses hold a limited tear reservoir.</li> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: square;"><i><b>Scleral lenses</b></i> (15mm to 25mm) place all lens bearing on the sclera. Scleral lenses are further subdivided as: mini-scleral lenses (15mm to 18mm) which have a somewhat limited tear reservoir capacity, and full scleral lenses (18mm to 25mm) which have an almost unlimited tear reservoir capacity.</li> </ul> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpWKvAB9pwSMVdnmkOQ5T4aWffqORhIiBZlzompD8mhyphenhyphen-PCy-d0pdp-UB1Zehw2bp8NwFpS8FNkmCIFYwbcaB_WLpt_FI28uRkezbUY5B7KMDzh8o4326rthKe-T7-0Z-fbeTYeeRg_E4/s1600/terminology.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="380" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpWKvAB9pwSMVdnmkOQ5T4aWffqORhIiBZlzompD8mhyphenhyphen-PCy-d0pdp-UB1Zehw2bp8NwFpS8FNkmCIFYwbcaB_WLpt_FI28uRkezbUY5B7KMDzh8o4326rthKe-T7-0Z-fbeTYeeRg_E4/s640/terminology.gif" width="640" /></a></div> <div> <span style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><span style="line-height: 17.981481552124023px;"><br /></span></span></div> <div> <span style="font-family: Arial, Helvetica, sans-serif;">This classification system allows manufacturers to design and market scleral lenses for specific types of patients. Practitioners can then utilize these products with predictive results.</span></div> <div> <span style="font-family: Arial, Helvetica, sans-serif;"><br /></span></div> <div> <h2 style="color: #1b4475; font-family: Arial, Helvetica, sans-serif; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> <span style="font-size: small;">MATERIALS</span></h2> </div> <div> <br /></div> <div> <div style="font-family: Arial, Helvetica, sans-serif; margin-bottom: 12px;"> The advent of hyper-Dk materials has significantly reduced hypoxic-related complications associated with scleral lens use. Using materials with Dk values of 100 or more is important with scleral lenses, because they semi-seal to the eye, making tear exchange relatively slow as compared to corneal GP designs. To prevent lens flexure, scleral lenses often are manufactured with thicknesses four times greater than that of corneal GPs. Using hyper-Dk lenses to maximize oxygen helps to compensate for permeability decreases secondary to increased lens thickness.</div> <div style="font-family: Arial, Helvetica, sans-serif; margin-bottom: 12px;"> Occasionally scleral lenses will exhibit poor on-eye wettability (<i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><strong>figure 1</strong></i>). If this occurs soon after the lens is dispensed, then it is most likely due to lab-related over-polishing or residual lab debris. Patients who have OSD may also have difficulty wetting a scleral lens secondary to their tear quality. In either case, the wettability can almost always be restored by plasma treating the lens. Instruct the lab to plasma treat each lens ordered and have lenses treated as needed if wettability decreases during the life of the lens.</div> <div style="font-family: Arial, Helvetica, sans-serif; font-size: 13px; margin-bottom: 12px;"> <br /></div> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9MW3AmyLJv0hVN5FwRxFgtEQx6A8DLdqK4PUwVLkQu332TEQXoJI6aZGa-e8X690SQMGH8TG2tdncHKi6_D-mnMj5G1GTqxg7hOz5V2-1iW1aYbFhcVgqC3vFaGUwsZKNgljbCh7w3-s/s1600/fig1.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9MW3AmyLJv0hVN5FwRxFgtEQx6A8DLdqK4PUwVLkQu332TEQXoJI6aZGa-e8X690SQMGH8TG2tdncHKi6_D-mnMj5G1GTqxg7hOz5V2-1iW1aYbFhcVgqC3vFaGUwsZKNgljbCh7w3-s/s1600/fig1.jpg" /></a></div> <div class="separator" style="clear: both; text-align: center;"> <br /></div> <div class="separator" style="clear: both; text-align: center;"> </div> <div style="font-family: Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: left;"> Occasionally scleral lenses will exhibit poor on-eye wettability (<i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><strong>figure 1</strong></i>). If this occurs soon after the lens is dispensed, then it is most likely due to lab-related over-polishing or residual lab debris. Patients who have OSD may also have difficulty wetting a scleral lens secondary to their tear quality. In either case, the wettability can almost always be restored by plasma treating the lens. Instruct the lab to plasma treat each lens ordered and have lenses treated as needed if wettability decreases during the life of the lens.</div> <h2 style="color: #1b4475; font-family: Arial, Helvetica, sans-serif; margin: 15px 0px 2px; padding: 0px; text-align: left; text-transform: uppercase;"> <span style="font-size: small;">SOLUTIONS</span></h2> <div style="font-family: Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: left;"> As with any other type of contact lens, solutions play an important role in the success of scleral contact lens wear. Scleral lenses can be cared for using approved GP lens cleaning and disinfecting products or off-label use of multipurpose soft lens solutions. Using preserved solutions with scleral lenses puts the patient at a greater risk for toxic reactions because residual solution can become trapped underneath the lens, which increases exposure time to the anterior ocular surface. Prescribing a hydrogen peroxide-based care system eliminates exposure to any potential toxins or antigens.</div> <br /> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvM3y9bylhuK2oaIspnsfqA9neLhfOxuNJEIvweo_UUmaavlwMG4o-vyPNB45UJVGPf0gxsZbN3epQv5ZVjjqNx0yhzNlECtfF9LBQJEb2Mb4jQRwyokd42-bg9KJRBzNyWxNii10wL8w/s1600/fig2.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="283" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvM3y9bylhuK2oaIspnsfqA9neLhfOxuNJEIvweo_UUmaavlwMG4o-vyPNB45UJVGPf0gxsZbN3epQv5ZVjjqNx0yhzNlECtfF9LBQJEb2Mb4jQRwyokd42-bg9KJRBzNyWxNii10wL8w/s400/fig2.jpg" width="400" /></a></div> <div class="separator" style="clear: both; text-align: center;"> <br /></div> <div class="separator" style="clear: both; text-align: center;"> </div> <div style="font-family: Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: left;"> Scleral contact lenses have to be filled with saline before application to prevent trapped air bubbles that compromise both fit and vision. Unfortunately bottled saline solutions contain preservatives that could induce a toxic reaction.</div> <div style="font-family: Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: left;"> Bottled, non-preserved solutions are available but pose two potential risks. First, there is the possibility of contamination if the bottle is used over several days. Secondly, although non-preserved, most of these solutions still contain a buffering agent that can be toxic to the patient.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">7,8</sup></div> <div style="font-family: Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: left;"> Alternatively you can prescribe off-label use of 0.9% sodium chloride solution that comes in 3ml single-use vials (<i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><strong>figure 2</strong></i>). The sodium chloride vials do not contain any buffers and eliminate the risk of contamination because they are single use.</div> <h2 style="color: #1b4475; font-family: Arial, Helvetica, sans-serif; margin: 15px 0px 2px; padding: 0px; text-align: left; text-transform: uppercase;"> <span style="font-size: small;">DESIGNS</span></h2> <div style="font-family: Arial, Helvetica, sans-serif; margin-bottom: 12px; text-align: left;"> There has been a dramatic increase in available scleral lens designs in the last five years (<i style="font-family: Tahoma, Arial, Helvetica, sans-serif;">see "<strong><a href="http://www.revoptom.com/continuing_education/tabviewtest/lessonid/108308/#scleral" style="color: #003366; text-decoration: initial;">Scleral Lens Designs</a></strong>"</i>). All of these designs require a diagnostic set for successful lens fitting. Fitting sets generally have diagnostic lenses that have increasing amounts of sag-ittal depth with standard peripheral curves or haptic section.</div> <br /> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5BqYUc3YaBSsUGXCyJdpDdlCv9X9OIic0QxTUNcWTtmDbWxytg97nC66I7V2oiUTbFp3GddhefRuyhyZ_eyiwkIc0Q67IsRaCliwDZobaxVTevPNqZey-TdT4Djaqdm8_6rAQiYVehP4/s1600/SceleralLensDesigns.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="430" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5BqYUc3YaBSsUGXCyJdpDdlCv9X9OIic0QxTUNcWTtmDbWxytg97nC66I7V2oiUTbFp3GddhefRuyhyZ_eyiwkIc0Q67IsRaCliwDZobaxVTevPNqZey-TdT4Djaqdm8_6rAQiYVehP4/s640/SceleralLensDesigns.gif" width="640" /></a></div> <div style="font-family: Arial, Helvetica, sans-serif; font-size: 13px; margin-bottom: 12px;"> <br /></div> <div style="font-family: Arial, Helvetica, sans-serif; margin-bottom: 12px;"> </div> <div style="margin-bottom: 12px;"> Determining which lens design to use can be a challenging first step to scleral lens fitting. Visiting with the various manufacturers that are represented as exhibitors at contact lens meetings can be a great way to learn which designs will be most beneficial for your practice.</div> <div style="margin-bottom: 12px;"> One of the major differences between available scleral lenses is the amount of customization that can be done on a specific design. Some scleral lenses offer only a limited amount of change that can be made to the standard parameters represented by the diagnostic lens. For the novice scleral lens fitter, this can be somewhat helpful because it can simplify the fitting process. However, some patients may require more creative changes to achieve a successful fit; for these cases, using a lens design that has unlimited customization will be beneficial.</div> <ul style="list-style-type: square;"> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: square;"><i><b>Toric and quadrant-specific design. </b></i>Most standard manufactured scleral lens designs have spherical front and back surface optic zones. Normally, this design setup fits the patient adequately because the lenses are vaulted completely off the cornea surface; therefore, corneal toricity or irregularity is often not a factor.</li> </ul> <div style="margin-bottom: 12px;"> Scleral lenses effectively mask both regular and irregular astigmatism by means of liquid reservoir. Residual astigmatic error from a scleral lens correction is often the result of lens flexure that can be eliminated by increasing the center thickness of the lens or improving the lens fit. Occasionally, residual astigmatism can manifest from the crystalline lens and thus is not inherently corrected for by the scleral lens. If the amount of residual astigmatism is significant, the patient can wear glasses over their scleral lenses to correct the astigmatic error. Alternatively, the scleral lens can be manufactured with front surface toricity. In this case, the lens will need to be ballasted to orient and stabilize the lens position.</div> <div style="margin-bottom: 12px;"> Typically, scleral lens designs come with a standard spherical back surface haptic. It is now known that the scleral is not spherical, but non-rotationally symmetrical.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">2</sup> Scleral asymmetry worsens with increasing distance from the corneal limbus. Minor differences between the spherical lens haptic and the sclera may be offset due to the spongy scleral conjunctiva.</div> <div style="margin-bottom: 12px;"> Some patients have asymmetric scleral anatomy that results in a poor fitting relationship when fit with a scleral lens that has a spherical haptic surface. These poorly fitting lenses often exhibit a with-the-rule appearance. The lens will have 3 o'clock and 9 o'clock compressions, as well as excessive lift at the 6 o'clock and 12 o'clock positions. In these instances, some manufacturers offer toric back surface haptic (peripheral curves), which can dramatically improve the scleral lenses fitting relationship.</div> <div style="margin-bottom: 12px;"> Some practitioners report routinely using back surface haptic designs for their scleral lens fits. Esther-Simone Visser, M.Sc., and colleagues reported significant increases in comfort, visual quality and overall satisfaction when patients were switched from back surface spherical designs to back surface toric designs.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">9</sup> Anecdotally, patients with toric back surface haptics report less accumulation of reservoir debris trapped between the lens and the eye during wear.</div> <div style="margin-bottom: 12px;"> A few labs are able to manufacture scleral lenses with quadrant-specific curves for either the back surface optical zone or the haptic portion when troubleshooting an extremely complex scleral lens fit. For these cases, optical coherence tomography (OCT) of a diagnostic lens is helpful in determining quadrant-specific changes.</div> <ul style="list-style-type: square;"> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: square;"><i><b>Multifocals. </b></i>Scleral lenses primary have been used to improve distance vision for patients who have corneal irregularity. Recently, however, there has been some interest in using multifocal scleral lenses to correct presbyopia. Theoretically, multi-focal scleral lenses could be used for patients who have either regular or irregular corneas. Scleral lenses don't translate on the eye, so the available multifocal scleral lens designs incorporate simultaneous designs with center near optics. Unfortunately, multifocal optics may not work well for the irregular corneal patient if they have significant corneal scar tissue or significant residual higher-order aberrations.</li> </ul> <h2 style="color: #1b4475; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> <span style="font-size: small;">NOTCHING LENSES</span></h2> <div style="margin-bottom: 12px;"> Scleral GP lenses fit onto the sclera. Scleral GP lenses can fit over mild pinqueculas, but their firm nature prevents them from draping scleral obstacles that have significant elevation. In these cases, a notch can be beveled into the scleral lens so that the lens bypasses the obstacle. Scleral notches can improve the fit for patients who have moderate to severe pinqueculas or conjunctival blebs resulting from trabeculectomy.</div> <div style="margin-bottom: 12px;"> A diagnostic lens that is notched can be kept in the office for fitting purposes. Photos of the diagnostic lens can be sent to the lab for evaluation and modification of the notch that will be beveled into the prescribed scleral lens. Notches have to be kept shallow because they will induce bubbles if they are cut too deep. For this reason, it's best to use a corneal-scleral lens or mini-scleral lens because a relatively smaller lens will require a shallower notch.</div> <div style="margin-bottom: 12px;"> When the lens is dispensed, we instruct the patient to insert it like a puzzle piece so that the notched area is aligned with the scleral obstacle. At the follow-up visit, monitor the patient to make sure that the lens is still adequately clearing the obstacle and not creating any tissue disruption, which is especially important in the case of conjunctival blebs.</div> <h2 style="color: #1b4475; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> <span style="font-size: small;">PIGGYBACKING LENSES</span></h2> <div style="margin-bottom: 12px;"> For the irregular cornea patient, scleral lenses are considered the lens of choice when all other design modalities have failed. Most of the time, as long as the diameter is large enough, a scleral lens can completely vault up over almost any cornea. There are rare cases where the practitioner will have a difficult time with complete corneal clearance resulting in some areas of lens touch.</div> <div style="margin-bottom: 12px;"> If the patient is asymptomatic and their cornea is without any disruption, then lens changes aren't always necessary and the patient can be monitored. However, if the patient is symptomatic--especially if the cornea shows epithelial disruption that is associated with the lens touch--then the practitioner needs to address the fitting relationship immediately.</div> <div style="margin-bottom: 12px;"> It is best if the lens vault or design can be changed to improve the fit. If, however, the practitioner is unable to improve the fitting relationship, then a soft lens placed under the scleral lens can be used as a piggyback system. The soft lens effectively cushions the cornea against any scleral lens-related bearing.</div> <div style="margin-bottom: 12px;"> If a standard molded design fits on the cornea reasonably well, then start with a daily disposable silicone hydrogel (SiHy) lens that the patient wears underneath the best-fit scleral contact. A daily disposable eliminates the need for multiple solutions and prevents lens-related solution interactions. A SiHy lens will help to maximize oxygen to prevent hypoxic-related complications.</div> <div style="margin-bottom: 12px;"> If a standard molded soft lens design does not adequately fit, then a custom fit lathe cut design can be used. Diameters larger than 14.5mm may interfere with the lens haptic to sclera relationship and disrupt the scleral lens fit.</div> <br /> <div style="font-family: Arial, Helvetica, sans-serif; margin-bottom: 12px;"> </div> <h2 style="color: #1b4475; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> <span style="font-size: small;">LENS APPLICATION</span></h2> <div style="margin-bottom: 12px;"> Scleral lens application is challenging because of the relatively increased overall lens diameter. Patients who are disabled and/or elderly may especially have trouble effectively applying scleral lenses. Dalsey Adaptives, LLC has developed the See-Green device that can be used to help patients successfully apply their scleral contact lenses.<sup style="font-family: Tahoma, Arial, Helvetica, sans-serif;">10</sup>The See-Green system comes with a stand that holds a lighted plunger (<i style="font-family: Tahoma, Arial, Helvetica, sans-serif;"><strong>figure 3</strong></i>). Using this system, the patient no longer has to hold the lens, but rather lowers their eye onto it, which leaves both hands free for improved lid control. The light at the center of the plunger is used as a target to allow for central positioning</div> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2tbQyA3o_dqPm5XTE6IXKukx-Kj6ThxSdeBYWaUsoIUeYArH8rdGMxKRg6eBTEEcqrJKYYHfeS-qGrA_XUbGVleW9AREvpUtihbwNBDCCo6SSLKcjCV00mlXrgn6EU3Mbo2PY78ft-X0/s1600/fig3+(1).jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj2tbQyA3o_dqPm5XTE6IXKukx-Kj6ThxSdeBYWaUsoIUeYArH8rdGMxKRg6eBTEEcqrJKYYHfeS-qGrA_XUbGVleW9AREvpUtihbwNBDCCo6SSLKcjCV00mlXrgn6EU3Mbo2PY78ft-X0/s1600/fig3+(1).jpg" /></a></div> <div style="font-size: 13px; margin-bottom: 12px;"> <br /></div> <div style="font-size: 13px; margin-bottom: 12px;"> </div> <div style="font-size: 13px; margin-bottom: 12px;"> Scleral lens use has increased exponentially over the last five years. Utilization of scleral lenses has expanded beyond the irregular cornea, as practitioners are now using scleral lenses for patients with high refractive errors and presbyopia. Solution, material and design updates will continue to improve scleral lens fitting success.</div> <h2 style="color: #1b4475; font-size: 12pt; margin: 15px 0px 2px; padding: 0px; text-transform: uppercase;"> REFERENCES</h2> <ol class="references" style="font-size: 8pt;"> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: decimal;">Schornack MM, Patel SV. Scleral lenses in the management of keratoconus. Eye Contact Lens. 2010 Jan;36(1):39-44.</li> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: decimal;">Pecego M, Barnett M, Mannis MJ, Dublin-Johnson B. Jupiter scleral lenses: the UC Davis Eye Center experience. Eye Contact Lens. 2012 May;38(3):179-82.</li> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: decimal;">Schornack MM, Baratz KH, Patel SV, Maguire LJ. Jupiter scleral lenses in the management of chronic graft versus host disease. Eye Contact Lens. 2008 Nov;34(6):302-5.</li> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: decimal;">Jacobs DS, Rosenthal P. Boston scleral lens prosthetic device for treatment of severe dry eye in chronic graft-versus-host disease. Cornea. 2007 Dec;26(10):1195-9.</li> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: decimal;">DeNaeyer G. A New Way To Classify Scleral Contact Lenses. CL Spectrum. 2011 Oct.</li> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: decimal;">van der Worp E. A Guide to Scleral Lens Fitting [monograph online]. Scleral Lens Education Society; 2010. Available at: http://commons.pacificu.edu/mono/4/ (accessed May 2012).</li> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: decimal;">Imavasu M, Hori Y, Cavanagh HD. Effects of multipurpose contact lens care solutions and their ingredients on membrane-associated mucins of human corneal epithelial cells. Eye Contact Lens. 2010 Nov;36(3):361-6.</li> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: decimal;">Gorbet MB, Tanti NC, Jones L, Sheardown H. Corneal epithelial cell biocompatibility to silicone hydrogel and conventional hydrogel contact lens packing solutions. Mol Vis. 2010 Feb 19;16:272-82.</li> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: decimal;">Visser ES, Visser R, van Lier HJ, Otten HM. Modern scleral lenses part II: patient satisfaction. Eye Cont Lens. 2007;33(1):21-5.</li> <li style="font-family: Tahoma, Arial, Helvetica, sans-serif; line-height: 18px; list-style-type: decimal;">The See-Green Lens Inserter. Dalsey Adaptives. Available at: www.dalseyadaptives.com (accessed May 2012).</li> </ol> <br /> </div> <br /> <br /> <br /> <br /> Visualizacion optima 1600x900 pixel Comenta.esta.publicación</div>

Lente escleral de hoy

Lentes esclerales son ya universales - se utiliza no sólo para los pacientes córnea irregular, pero también para el tratamiento de er...

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