Prevalence of Macular Disorders Assessed by Oct in Adults 45 Years and Older From Parintins - The Brazilian Amazon Region Eye Survey (BARES)

Background To provide population-level estimates of OCT-detected macular pathology in adults living in the Brazilian Amazon region. Methods Population-based, cross-sectional study. Eligible participants were residents aged ≥ 45 years identified through cluster sampling (20 clusters: 14 urban and 6 rural) in Parintins City, Amazonas, Brazil. Ophthalmic examinations included visual acuity testing, biomicroscopy, fundoscopy, and subjective refraction. A subset underwent spectral-domain OCT (SD-OCT; iVue-100, Optovue) using macular mapping protocols. OCT images were graded for predefined abnormalities involving the vitreoretinal interface, inner retina, outer retina/retinal pigment epithelium (RPE)/choroid, and ganglion cell complex (GCC). Generalized estimating equations (GEE) were used to evaluate factors associated with any OCT abnormality. Statistical significance was set at p  < 0.05. Results Of 2,384 eligible individuals, 2,041 (85.7%) were examined and 588 (28.8%) underwent OCT (1,176 eyes), of which 1,069 eyes (90.9%) were gradable. OCT macular abnormalities were detected in at least one eye in 180 participants (30.6%). Overall, outer retinal layer changes were most frequent, followed by GCC thinning and epiretinal membrane. OCT abnormalities were independently associated with older age and lower educational level. Structural abnormalities were identified in 340 (31.8%) eyes; of these, 208 (19.5%) showed changes also detectable on dilated fundus examination, whereas 132 (12.3%) had a clinically normal funduscopic appearance. Clinically notable lesions were detected in 46 (4.3%) eyes, including signs of late AMD in 27 (2.5%) eyes, diabetic maculopathy in 6 (0.6%), lamellar macular hole in 6 (0.6%), full-thickness macular hole in 3 (0.3%), and central serous chorioretinopathy in 4 (0.4%) eyes. Among 774 eyes clinically normal at fundoscopy, OCT revealed subclinical disease in 127 (16.4%). Conclusions In this underserved Amazonian population, approximately one-third of gradable eyes showed OCT-detected macular abnormalities, many of them subclinical on fundoscopy. Diabetic maculopathy, choroidal neovascular membranes, and late AMD showed very low prevalence and limited epidemiologic weight in this setting. Incorporating OCT into population-based surveys enhances detection and refines burden estimates of subclinical retinal disease and vision-threatening conditions in aging populations.