The association between macular pigment optical density and visual function outcomes: a systematic review and meta-analysis.

Objectives: To conduct a systematic review and meta-analysis on data related to macular pigment optical density (MPOD) and visual function in adults with healthy eyes.

Methods: MEDLINE®, Cochrane, and Commonwealth of Agriculture Bureau abstracts databases were searched for English-language publications between 1946 and August 2018. Included studies examined correlation of MPOD and visual function in adults with healthy eyes at all timepoints and all designs, except for case-control, case reports, and reviews. Visual function outcomes of interest included photostress recovery, contrast sensitivity, visual acuity, glare sensitivity/disability, and dark adaptation. Random effects model meta-analyses combined study-level correlation (r).

Results: Twenty-two publications were included. In meta-analysis MPOD was found to be significantly correlated with contrast sensitivity at 30' (two studies, summary r: 0.37; 95% CI 0.15, 0.56), and at 1° eccentricity with a spatial frequency of 7, 11, and 21 cpd (three studies, summary r: 0.31; 95% CI 0.06, 0.52), with photostress recovery at a 1° eccentricity with a moderate background, 10 cpd, and 16% contrast (two studies, summary r: -0.17; 95% CI -0.31, -0.02), and at 30' (four studies, summary r: -0.57; 95% CI -0.78, -0.24), and with glare disability at 30' eccentricity with a log scale at 460 nm (three studies, summary r = 0.47; 95% CI 0.32; 0.59). There were insufficient data for meta-analysis for other visual functions.

Conclusions: Our review identifies a link between MPOD and visual function with significant correlations with photostress recovery, glare disability, and contrast sensitivity.