Jang and associates state unequivocally in the introduction section of their valuable article reporting the effect of yellow-tinted (“blue-blocking”) intraocular lenses (IOLs) on short-wavelength automated perimetry that: “As a result of exposure to ultraviolet-A (UVA, 315–400 nm) and blue light (400–480 nm), the risk of development or progression of age-related macular degeneration (AMD) is known to be increased.”
Colorless UV-transmitting and UV-blocking IOLs have been used for many decades. If the authors’ statement were correct, then there should be compelling epidemiologic evidence that cataract surgery accelerates the development and progression of AMD. In fact, quite the opposite has been found in several large, well-designed recent studies, including those by Dong and associates and Chew and associates. Moreover, 10 of 12 major epidemiologic studies fail to support the phototoxicity-AMD hypothesis, which conjectures that hypothetical cumulative retinal damage attributable to repetitive acute retinal phototoxicity (photic retinopathy) from environmental light exposure is a significant risk factor for AMD. Additionally, irradiating cell cultures and experimental animals with brilliant light exposures cannot simulate AMD, just as scalding water exposures cannot simulate a lifetime of bathing in warm water. In essence, a preponderance of scientific evidence refutes rather than supports the authors’ introductory statement, and it is certainly not “known” that “exposure to ultraviolet-A (UVA, 315–400 nm) and blue light (400–480 nm)” increases “the risk of development or progression of age-related macular degeneration (AMD).”
The authors’ introductory statement in no way diminishes the value of their scientific work. Their study supports the previous findings of Wirtitsch and associates, which they did not reference. Wirtitsch and associates also used short-wavelength automated perimetry to compare the visual performance of pseudophakes with colorless and blue-blocking IOLs in contralateral eyes. Wirtitsch and associates found that yellow-tinted IOLs adversely affect blue/yellow foveal threshold and contrast acuity, confirming Pierre and associates’ luminance contrast results and earlier analytical studies on the negative effects of yellow IOL filters on pseudophakic visual perception.
IOL chromophores cannot prevent AMD because cataract surgery does not cause it. Furthermore, yellow-tinted IOLs provide far less retinal photoprotection than senescent crystalline lenses that do not prevent AMD. Nonetheless, blue-blocking IOLs eliminate roughly half the light in a third of the visible spectrum. Thus, Jang and associates’ valuable findings should not be surprising and they help further dispel the misperception that light loss from yellow-tinted chromophores cannot adversely affect photoreception. Unfortunately, what is “known” can be highly resistant to scientific evidence.