By James M. Stringham, PhD
Ample empirical evidence exists showing the benefits of macular carotenoids—lutein, zeaxanthin, and meso-zeaxanthin—supplementation for visual performance. In both normally sighted1and some clinical populations, such as age-related macular degeneration2and diabetes/diabetic retinopathy,3significant improvements have been determined in placebo-controlled trials for contrast sensitivity, vision in glare, and speed of visual processing. Unfortunately, little work has been devoted to the potential for macular carotenoids to influence visual performance in glaucoma patients.
It is known that those with glaucoma generally struggle with many of the visual tasks that have been shown to improve with macular carotenoid supplementation, including contrast sensitivity,4glare,5and dark adaptation.6Given glaucoma’s status as the leading cause of irreversible blindness in the United States and the world, any means of visual improvement would certainly be welcome.
In the summer of 2019, as part of a larger trial at the Duke Eye Center in North Carolina, a patient with severe glaucoma began supplementing daily with 22mg of lutein, zeaxanthin, and meso-zeaxanthin. The goal of the study is to determine whether effects of macular carotenoid supplementation on visual performance in glaucoma patients is similar to that of other populations—namely that it has the potential to improve vision in parameters, such as contrast sensitivity, processing speed (i.e. CFF), glare, and dark adaptation. The patient, a 74-year-old African-American male, supplemented for 6 months and had visual performance testing completed at baseline, 3 months, and 6 months (final visit to the lab). Presented here are baseline versus 6-month data:
As can be seen in the table, improvement was found to occur across the board—and appeared to be commensurate with increases found for macular pigment optical density (MPOD). This of course is very encouraging, albeit preliminary. Completion of data collection for the larger, placebo-controlled study is planned for the Spring of 2021.
Study Impact on Glaucoma Patients
Should these findings hold for the overall glaucoma patient population, then macular carotenoid supplementation represents a positive step in the management of the disease. To be sure, we do not think of supplementation with lutein, zeaxanthin, and meso-zeaxanthin as atreatmentfor glaucoma, but rather as a way to improve vision and quality of life in glaucoma patients. To this end, optometry can play a major role. Stay tuned!
Stringham JM, Stringham NT, O'Brien KJ. Macular carotenoid supplementation improves visual performance, sleep quality, and adverse physical symptoms in those with high screen time exposure. Foods. 2017;6(7):47.
Akuffo KO, Beatty S, Peto T, et al. The impact of supplemental antioxidants on visual function in nonadvanced age-related macular degeneration: a head-to-head randomized clinical trial. Invest Ophthalmol Vis Sci. 2017;58(12):5347-5360.
Moschos MM, Dettoraki M, Tsatsos M, et al. Effect of carotenoids dietary supplementation on macular function in diabetic patients. Eye and Vis. 2017;4:23.
Ross JE, Bron AJ, Clarke DD. Contrast sensitivity and visual disability in chronic simple glaucoma. Br J Ophthalmol.1984;68(11):821-827.
Nelson P, Aspinall P, Papasouliotis O, Worton B, O'Brien C. Quality of life in glaucoma and its relationship with visual function. Journal of Glaucoma. 2003;12(2):139-150.
Drum B, Armaly MF, Huppert W. Scotopic sensitivity loss in glaucoma. Arch Ophthalmol. 1986;104(5):712-717.