Ethnic Differences in the Presentation Patterns of Type 3 Macular Neovascularization

PURPOSE: To evaluate differences in the presentation patterns of Type 3 macular neovascularization (T3 MNV) secondary to age-related macular degeneration in Caucasian and Asian populations. METHODS: This retrospective, multicenter, comparative case series included treatment-naïve T3 MNV patients from Switzerland, Italy, and South Korea. All patients underwent comprehensive multimodal imaging. The topography of T3 MNV foci was mapped relative to the Early Treatment Diabetic Retinopathy Study(ETDRS) grid. Demographic and clinical variables were analyzed with respect to ethnicity, and discriminant score performance was assessed for differentiating Caucasian and Asian populations. RESULTS: A total of 301 eyes (181 European and 120 Korean) from 248 patients were included. Asian patients were significantly younger at presentation(76.1±6.9 vs. 81.1±6.1 years, p<0.001), with T3 MNV lesions located closer to the foveal center (mean distance: 810.7±329.0 vs. 1061.4±300.8 μm, p<0.001). Central ETDRS circle involvement was observed in Asians (17.5% vs 4.4%; p<0.001). Subfoveal choroidal thickness was similar between groups (154.1±72.1 vs. 153.3±71.0 μm, p=0.904). The prevalence of reticular pseudodrusen was higher in Caucasians than in Asians(89.0% vs. 74.2%; p=0.001). Multivariable analysis demonstrated that age(β=0.128, p<0.001), mean foveal distance (β=0.003, p<0.001) and RPD (β=1.150, p=0.003) had the strongest associations with ethnicity. In the discriminant model analysis, age and foveal distance emerged as significant discriminant features (Δ-C-index decreases=0.03 and 0.04, respectively). CONCLUSION: The presentation patterns of T3 MNV in the Caucasian and Asian populations demonstrated both shared and distinct characteristics. These findings suggest that while T3 MNV may involve common pathophysiological mechanisms across ethnicities, certain contributing factors may vary between populations.