Age-Related Macular Degeneration in Chronic Kidney Disease: A Meta-Analysis of Observational Studies

Background: Age-related macular degeneration (AMD) is an important cause of blindness in aged people. Chronic kidney disease (CKD) was reported to be associated with a higher risk of AMD. However, supporting evidence was inconsistent between studies. This work intends to examine whether a positive association exists between CKD and AMD by systematic review and meta-analysis. Methods: A systematic search of electronic databases (Medline, PubMed, Cochrane and EMBASE) and reference lists on June 2017. The key inclusion criteria were controlled trials that investigated the relationship between AMD and CKD. The outcome measures included risk ratios and/or occurrence rates of AMD in CKD vs. non-CKD population. Data were pooled according to the type of AMD by random effect model. Results: Twelve observational studies (3 cohorts, 2 case controls, and 7 cross-sectionals) with a total 335,601 participants were included. Eleven studies reported risk ratios and 9 reported occurrence rates. Pooled prevalence for early, advanced, and any AMD were all higher in the CKD population than in the non-CKD population. The pooled multivariate adjusted OR of CKD vs. non-CKD was 1.49 (95% CI 1.11-2.02) for early, 1.55 (95% CI 1.05-2.27) for exudative, 1.58 (95% CI 1.12-2.23) for advanced, and 1.35 (95% CI 1.05-1.73) for any AMD. However, high statistical heterogeneity and methodological diversity existed. Moreover, results were inconsistent between different study designs. Conclusions: The overall results support a positive association between CKD and AMD, although some limitations exist. Given the risk that AMD is increased in CKD, regular eye screenings for the CKD population is recommended for an early detection and intervention.