The Effect of Dietary Supplementations on Delaying the Progression of Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis

Abstract

Purpose: Age-related macular degeneration (AMD) is a neurodegenerative ophthalmic disease. The purpose of this systematic review (SR) and meta-analysis was to evaluate if dietary supplementation alone or in combinations might delay the progression of any of the stages of AMD. Methods: A SR and meta-analysis identifying cohort studies and randomized controlled trials (RCTs) evaluating the effect of supplements in patients diagnosed with AMD. PubMed, Scopus, Web of Science, CINAHL, and Cochrane were searched through 8th October 2021. Results: Twenty studies, examining 5634 participants ranging from 55 to 80 years, were included in the SR. Eight studies were selected for meta-analysis (414 and 216 subjects in the intervention and control groups). Lutein and zeaxanthin plus n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) supplementation showed significant improvements in best-corrected visual acuity (BCVA) (SMD: -1.99, 95% CI: -3.33, -0.65) compared to the control group. Multifocal electroretinogram results (mfERG) were significantly improved overall (SMD: 4.59, 95% CI: 1.75, 7.43) after lutein plus zeaxanthin supplementation. Conclusions: Combinations of lutein and zeaxanthin with n-3 LC-PUFA might be beneficial in preventing AMD progression and deterioration of visual function. Our results encourage initiating further studies with combinations of n-3 LC-PUFA, lutein, and zeaxanthin especially in early AMD patients.

Keywords: age-related macular degeneration; carotenoids; meta-analysis; omega-3 fatty acids; supplements; xanthophylls.

Figure 1

Prisma study flow diagram 2020.

Figure 2

Quality assessment of all randomized controlled trials [13,22,23,24,26,27,28,29,30,31,32,34,35,36,37,38,39,40,41].

Figure 3

Forest plot of BCVA values in studies where subjects were administered either lutein or lutein plus zeaxanthin; SD, standard deviation; SMD, standardized mean difference; CI confidence interval [22,27,37].

Figure 4

Forest plot of mfERG outcomes in studies where subjects were administered either lutein or lutein plus zeaxanthin; SD, standard deviation; SMD, standardized mean difference; CI, confidence interval [23,24].

Figure 5

Forest plot of BCVA in studies with lutein and zeaxanthin combined with n-3 LC-PUFA; SD, standard deviation; SMD, standardized mean difference; CI, confidence interval n-3 LC-PUFA (DHA and EPA) [26,29,39].