Artikel
About light and lenses: prophylaxis "light" for AMD?
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Veröffentlicht: | 22. September 2004 |
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Gliederung
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Actually there is a debate going on about the correlation between cataract surgery and risk or progression of age related macular degeneration. Based on epidemiological studies showing a correlation between AMD and cataract surgery, the theory was postulated, that the natural yellow color change of an old lens is a protective factor for AMD. Indeed the yellow-tinted lens results in a progressive increase in absorbance within the blue range of the visible spectrum. Filtering the shorter wavelengths of the visible spectrum is particularly significant because it is also this portion of the spectrum that produces photochemical damage to the retinal pigment epithelium (RPE). It is now generally accepted that at least 1 of the intracellular chromophores responsible for the blue light sensitivity of RPE cells is the lipofuscin constituent A2E. Thus, replacement of a senile cataractous crystalline lens with a colorless IOL may leave the RPE vulnerable at an age when its content of blue light sensitive A2E is already high. Based on these findings the use of yellow-tinted IOL was proposed. Whether or not such IOL are capable to reduce the risk or progression of AMD is not clear. For the validation of such therapies it is necessary to get a better understanding of intraocular changes following cataract surgery. In the present paper results about the influence of light and lenses on biological changes finally leading to AMD are presented. These results could be a basis for future evaluations.