Refractive Errors and Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis

Abstract

Purpose: To determine the associations between refractive errors and age-related macular degeneration (AMD) by systematic review and meta-analysis of observational studies.

Methods: We searched PubMed from its inception till March, 2012 for population-based studies with data on refractive error and AMD assessed from retinal photographs at baseline and/or follow-up. Study-specific odds ratios (ORs) for cross-sectional studies or hazard ratios (HRs) for cohort studies were combined using random effect models.

Results: 6 cross-sectional studies and 3 cohort studies contributed to the analyses. Analysis of the six cross-sectional studies showed that hyperopia was associated with higher odds of AMD (pooled OR hyperopia versus emmetropia: 1.16; 95% confidence interval (CI): 1.04-1.29) while myopia was associated with lower odds of AMD (pooled OR myopia versus emmetropia: 0.75; 95% CI: 0.61-0.92). Analysis from the three cohort studies showed non-significant associations, though there was a marginally non-significant association of myopia with AMD (pooled HR 0.84; 95% CI, 0.68, 1.04). Analysis of the 5 cross-sectional and 2 cohort studies showed that each diopter increase in spherical equivalent was associated with increased odds of both prevalent (pooled OR: 1.09; 95% CI: 1.06, 1.12) and incident (pooled HR: 1.06; 95% CI: 1.02, 1.10) AMD. In three cross-sectional studies with data on axial length, each mm increase in axial length was associated with a decreased odd of prevalent AMD (pooled OR: 0.76; 95% CI: 0.69, 0.85).

Conclusions: This systematic review and meta-analysis shows that AMD are more prevalent in hyperopic eyes and less prevalent in myopic eyes. Prospective data suggest that myopic persons may be at a lower risk of AMD but evidence on the association between hyperopia and AMD is limited. Clinically, these data suggest that clinicians should be aware that risk of AMD appears to vary by refractive status.

Keywords: 412 age-related macular degeneration • 676 refraction • 459 clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology