Evidence for the Role of Blue Light in the Development of Uveal Melanoma

Figure 1

(a) The young crystalline lens and cornea together filter UVA and UVB while allowing transmission of most blue light (defined as 400–500 nm) to the retina. Around 80–90% of blue light at 450 nm can pass through the young lens. (b) As the crystalline lens ages it yellows and progressively filters more blue light until, by the sixth or seventh decade, blue light transmission can be as low as 20% of that transmitted by the young lens. (c) Early types of IOLs used to replace the crystalline lens during cataract surgery effectively filter UV but do not block blue light. It is hypothesized that blue light reaching the retina increases the risk of preexisting dysplastic nevi (indicated as CN, choroid nevus) progressing to UM. A typical CN is shown in the small retinal photograph, while a UM is shown in the magnified retinal photograph. (d) Blue-light-filtering IOLs are designed to filter up to 50% of blue light. This models the natural filtering ability of the middle-aged eye, reducing potentially damaging radiation while not impacting on vision. We argue that preexisting CNs (shown in the small retinal photograph) are less likely to progress to UMs in this environment. CN, choroidal nevus; IOL, intraocular lens; UM, uveal melanoma; UV, ultraviolet; UVA, ultraviolet A; UVB, ultraviolet B.

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