JUL 29, 2011
In this experimental study, researchers conducted a colorimetric characterization of light-filtering intraocular lenses and the human crystalline lenses at various ages and found that blue light-filtering IOLs best reproduced the yellowing of the human lens at 40 to 50 years of age.
The crux of this never-ending battle for truth and justice is shown elegantly here. The nonblue-filtering IOLs let in more blue light than even a 4-year-old crystalline lens, whereas blue-filtering IOLs are similar to a 40- to50-year-old lens. This makes it hard to believe that we are causing depression and insomnia.
Included in the experiment were two blue light-filtering IOLs (AcrySof Natural SN60AT and AF-1 UY YA-60BBR), an IOL that filters ultraviolet-violet (UV-v) light and a standard UV light-filtering IOL, as well as the human crystalline lens at various ages.
The authors calculated the colorimetric coordinates of three IOLs of each model with different dioptric powers (16.0, 21.0 and 26.0 D) by measuring their transmission spectra using a microspectroscopy technique. Subsequently, a parameter (ΔE) that was proportional to the perceived color differences was defined. They compared the results they obtained for the IOLs with results of the human crystalline lens at different ages (4, 22, 41, 53 and 72 years) using values taken from the literature.
The authors found that none of the IOLs had the same colorimetric performance as the human crystalline lens. However, the two blue light-filtering IOLs, which had similar colorimetric behavior, best reproduced the yellowing of the human lens at 40 to 50 years of age. The standard UV light-filtering IOL (AcrySof SA60AT) had the greatest difference compared with the human lens, especially at the ages at which lens substitution is most frequent (i.e., greater than 53 years).