Relationship between refraction and prevalent as well as incident age-related maculopathy: the Rotterdam Study
PURPOSE: To study the relationship between baseline spherical equivalents (SphE) of refraction and prevalent as well as incident age-related maculopathy (pARM and iARM, respectively). METHODS: The study was performed as part of the Rotterdam Study, a population-based, prospective cohort study. The SphE (in diopters), measured with autorefraction and subjective optimization, was recorded in 6209 subjects aged 55 years or more. Aphakic or pseudophakic eyes at baseline were excluded. Stereoscopic transparencies of the macular region were graded according to the International Classification and Grading System. ARM was defined as large soft drusen with pigmentary changes, or indistinct drusen, or atrophic or neovascular age-related macular degeneration (AMD). For the prevalence analyses, ARM was classified into no, p(early)ARM, or pAMD, and in each subject the eye with the most advanced ARM and the corresponding refraction was selected. After a mean 5.2 years of follow-up, 4935 subjects had complete data for these incidence analyses. In each subject, the eye with iARM was selected. RESULTS: The age- and gender-adjusted odds ratio (OR) of pARM (n = 536) for every diopter of progress toward hyperopia was 1.09 (95% confidence interval [CI]1.04-1.13). For p(early)ARM (n = 440) the OR was 1.09 (1.04-1.14) and for pAMD (n = 96) the OR was 1.09 (1.00-1.19). Baseline refraction was significantly associated with increased risk of iARM (n = 497). For each diopter of progress toward hyperopia the OR was 1.05 (95% CI 1.01-1.10). Additional adjustments for smoking, atherosclerosis, and blood pressure did not alter the relationship. CONCLUSIONS: These population-based incidence data confirm results from prevalence and case-control studies that there is an association between hyperopia and ARM.