Abstract
Purpose:
Glaucoma patients commonly suffer from disability glare and the cause of this is poorly understood. There is emerging evidence that the macula is affected in early glaucoma. Macular pigment (MP) consisting of lutein (L), zeaxanthin (Z) and meso-zeaxanthin (meso-Z) is highly concentrated at the macula. MP possesses antioxidant properties and has a vital role in visual performance. It has been shown that dietary MP supplementation can improve glare symptoms in healthy individuals or those with age-related macular degeneration. Glaucoma subjects have recently been observed to exhibit significantly lower MPOD compared to age-matched healthy controls. This study comprises an analysis of the baseline visual function data collected as part of the Macular Pigment and Glaucoma Trial (ISRCTN56985060).
Methods:
All glaucoma participants underwent a detailed eye exam including MPOD (heterochromatic flicker photometry using the Macular Densitometer), contrast and glare sensitivity, photostress recovery time, Humphrey standard 10-2 visual fields and vision-related quality of life questionnaires with particular emphasis on glaucoma and glare disability (TyPE SPEC and Glaucoma-Activity Limitation, GAL-9).
Results:
A total of 67 glaucoma subjects were recruited to the trial (38 male, 29 female). The mean age of participants was 64.8 years (range 36-84 years). There was a positive and statistically significant correlation between MPOD and mean deviation (MD) from the visual field analysis (r = 0.29, p = 0.04). Statistically significant relationships were observed between both the TyPE Spec self reported glare symptoms and mean deviation results with measures of glare disability. No statistically significant relationships were observed between MPOD and any other measure of visual function (p > 0.05 for all).
Conclusions:
Although there was no baseline association between MPOD and parameters of psychophysical function including acuity and contrast, it is interesting to note the significant relationship between MP and MD, a measure of severity of visual field loss. Furthermore, the inter-relationships observed between self reported glare symptoms, MD and glare disability suggest that lower MP levels in the presence of global central visual field loss as a potential factor in the development of glare symptoms among glaucoma subjects.
Keywords: 587 macular pigment •
642 perimetry