Impact of excess light and yellow filters on accumulation of lipofuscin

Purpose. Previous reports suggest excess high energy, short wave light increase lipofuscin fluorophore accumulation in the retinal pigment epithelium layer. Oxidation of lipofuscin has been implicated in the genesis of macular degeneration. By taking advantage of the increased exposure to light by optometry students, we tested whether optometry students accumulate more lipofuscin fluorophores than similarly aged allied health students and whether yellow filters alter lipofuscin accumulation. Method. The sample consisted of 54 non-optometry students (Mean age27, 4.1SD; 63% Female), 62 first-year optometry students (Mean age 27, 4.9SD; 55% female), and 39 second-year students (Mean age 26, 3.8SD, 54% female). First year practice patients were exposed primarily to anterior segment biomicroscopy, while second year practice patients included posterior segment biomicroscopy with condensing lens and binocular indirect ophthalmoscopy sessions. A two distribution mixture model estimated the gray scale of the fluorescent lipofuscin ring around the macula. Results. There was significantly less luminance intensity in optometry students (Mean 70.8 grayscale) relative to non-optometry students (Mean 76.2 grayscale, F = 5.3, p=.024) which was opposite from our prediction. Covariates included ge (b=.9,p=.002) and baseline lipofuscin (b=1.1, p Conclusion. Our results were more consistent with oxidation of lipofuscin fluorophores than accumulation following the excess exposure to light as practice patients. The study revealed intriguing trends in a challenging environment that suggested the topic is worth further investigation in a more rigorous experimental environment. The bottom line however is that we do not trust our results over time due to the systematic effect of multiple camera flashes that were not controlled across patients. We sincerely believe this study needs replicated with an autofluorescence camera that has a reference point to adjust for the physical conditions