Lipofuscin RPE Imaging in Vegetarians and Non-vegetarians: Dietary and Age Effects

Abstract

Purpose : Identify the relationship between vegetarian vs. non-vegetarian diet and lipofuscin build up in the retinal-pigmented epithelium (RPE) of an adult South Asian population (age 40-55 yrs) using fundus autofluorescence (FAF) imaging and compare results to those from a similar previous study comparing lipofuscin concentration in ages 20-25 yrs.

Methods : Sixty two subjects underwent FAF imaging (mean 47 yrs, SD 4) using a Canon CR-2 Plus AF retinal camera with an 18 Mp CMOS sensor fitted with an exciter (535-585 nm wide band) and barrier filter (605-715nm). All monochromatic images were captured without mydriatic agents at a flash setting of 300 w/sec with an angle of 45° and corrected for auto-exposure (Adobe Photoshop V 7.02). Quantitative autofluorescence measurements of a 35.5 mm² rectangle in the paracentral retina (P) were used as a measure of lipofuscin accumulation. Mean, SD and T-tests allowed comparison of autofluorescence in vegetarians vs. non-vegetarians ages 40-55 yrs as well as for comparison of vegetarians and non-vegetarians in this study (age 40-55 yrs) to their corresponding group in our pilot study (age 20-25 yrs).

Results : Sixty-two eyes were analyzed (47% females, all South Asian decent, 1.6% smokers); of those, 48% percent were vegetarian, 52% non-vegetarian (defined as eating meat more than ½ their life). Autofluorescence scores in P were significantly different (p < 0.05) between vegetarians and non-vegetarians in the older population. The average levels of autofluorescence are included in Table 1.

Conclusions : In this cohort group ages 40-55 yrs, vegetarians had statistically significant lower levels of FAF than non-vegetarians (p=6.59x10^-10*) with a 34% increase in levels of mean autofluorescence luminance in P seen in non-vegetarians. Results from our pilot study showed a 23% increase in levels of mean autofluoresnce luminance in P from vegetarians ages 20-15 yrs to non-vegetarians in the same age range. When compared to the pilot study, this follow-up study supports our initial findings and also identifies the increase in autofluorescence seen with increased age. Further studies will include analysis of FAF quantitative scores in healthy and non-healthy RPE as well as gender specific analysis.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

 

Table 1. T-test results from comparison of age (2 tail, 3) and FAF score in P (1 tail, 3) seen in vegetarians vs. non-vegetarians ages 40-55 yrs (*p<0.05).