Purpose: Age-related macular degeneration (AMD) and renal impairment are both associated with cardiovascular risk factors and with alterations in the complement pathways. There are few data on the association of AMD with chronic kidney disease.
Methods: People who were visually impaired (binocular acuity < 6/18) due to AMD (ascertained from review of medical notes; n = 516) were compared to people with normal vision (6/6 or better; n = 2755). Cases with AMD and controls derive from a population-based cross-sectional study of people aged 75 years and over registered with 49 family practices in Britain. Glomerular filtration rate (eGFR) was estimated with the Modification of Diet in Renal Disease formula and proteinuria assessed by dipsticks.
Results: After adjusting for a wide range of confounding factors, the presence of proteinuria was positively associated with AMD among men (odds ratio (OR) 2.06, 95% confidence interval (CI) 1.05, 4.04) but not in women (OR 0.62 95%CI 0.36,1.08). Among men, eGFR < 45 ml/min/1.73 m(2) was associated with AMD but not after adjusting for proteinuria. This was not observed for women. Both proteinuria and eGFR showed different associations with AMD by sex (p-values for interaction < 0.05).
Conclusions: Proteinuria appears to be a risk factor for AMD among men but not among women, possibly due to measurement errors in detecting proteinuria in women.