Association of Choroidal Thickness with Intermediate Age-Related Macular Degeneration in a Japanese Population

Purpose: To determine the relationship of choroidal thickness with the early stages of age-related macular degeneration (AMD) and their disease features in a Japanese population. Design: Cross-sectional survey. Participants: A total of 1293 Japanese persons 65 to 86 years of age residing in the Saku area who underwent eye screening as part of the Japan Public Health Center-based Prospective Study. Methods: Comprehensive ophthalmic assessment included fundus photography, measurement of intraocular pressure, and determination of refractive status. OCT with enhanced depth imaging mode was performed and subfoveal choroidal thickness was assessed. Multinomial logistic regression models were used to assess the relationships of choroidal thickness with the early stages of AMD, namely early AMD and intermediate AMD, and their disease features, after adjustment for potential confounders. Main Outcome Measures: Relationship of choroidal thickness with early AMD, intermediate AMD, and their disease features. Results: Of 1293 potential participants, 901 (mean age, 73.2 years) had choroidal thickness data, fundus photographs of sufficient quality, and no concomitant retinal disease (including 5 with late AMD). Mean choroidal thickness was 246.1 μm, 15.1% had early AMD, and 9.0% had intermediate AMD. After adjustment for age, gender, and refractive status, choroidal thickness was associated positively with presence of intermediate AMD (for each 1- standard deviation [SD] μm increase: odds ratio [OR], 1.43; 95% confidence interval [CI], 1.13–1.81), whereas no significant association was found with presence of early AMD. Among intermediate AMD features, choroidal thickness was associated positively with presence of AMD pigmentary abnormalities (associated with at least medium drusen; for each 1-SD μm increase: OR, 2.21; 95% CI, 1.42–3.42), whereas no significant association was found with presence of large drusen alone. In addition, among large drusen subtypes, choroidal thickness was associated positively with presence of pachydrusen (for each 1-SD μm increase: OR, 1.53; 95% CI, 1.10–2.13). Furthermore, exploratory analysis revealed that choroidal thickness was associated positively with presence of non-AMD pigmentary abnormalities (for each 1-SD μm increase: OR, 1.92; 95% CI, 1.31–2.18). Conclusions: Choroidal thickness seems to be associated with the pathology of intermediate AMD and its features in Asians.