Ethnic Differences in Type 3 Macular Neovascularization Noted

While type 3 MNV may involve common pathophysiological mechanisms across ethnicities, certain contributing factors may vary between populations. Photo: Mohammad Rafieetary, OD. Click image to enlarge. Type 3 macular neovascularization (MNV) is a distinct subtype of age-related macular degeneration (AMD) that is characterized by intraretinal neovascularization. Previous research has suggested that ethnic differences may influence the characteristics of MNV. A recent study published in Retina focused on characterizing potential population-specific presentation patterns and exploring the clinical implications in patients with this disease subtype. Its researchers examined the baseline clinical and demographic data of treatment-naïve patients of Caucasian and Asian descent diagnosed with type 3 MNV. Asian patients were approximately five years younger than Caucasian patients. In the Asian cohort, a substantial proportion of type 3 MNV cases occurred in individuals aged <70 years, whereas in Caucasians, all cases were observed in those aged ≥70 years.“This finding suggests that the key factors contributing to type 3 MNV development, including hypoxia, RPE cell migration and VEGF secretion, may emerge at a relatively younger age in Asian populations,” the study authors wrote in their paper. “Although the exact cause remains unclear, differences in the ocular and genetic characteristics may be involved.”This retrospective, multicenter, comparative case series included treatment-naïve type 3 MNV patients from Switzerland, Italy and South Korea. A total of 301 eyes (181 European and 120 Korean) from 248 patients were included. All patients underwent comprehensive multimodal imaging.Asian patients were significantly younger at presentation (76.1 years vs. 81.1 years), with type 3 MNV lesions located closer to the foveal center (mean distance: 810.7µm vs. 1061.4μm). Central ETDRS circle involvement was observed in Asians (17.5% vs. 4.4%). Subfoveal choroidal thickness was similar between groups (154.1µm vs. 153.3μm). The prevalence of reticular pseudodrusen was higher in Caucasians than in Asians (89.0% vs. 74.2%).Multivariable analysis demonstrated that age, mean foveal distance and reticular pseudodrusen had the strongest associations with ethnicity. In the discriminant model analysis, age and foveal distance emerged as significant discriminant features.“We postulate that if choroidal thinning contributes to hypoxia responsible for type 3 MNV, a critical degree of choroidal thinning may be required to trigger the disease, regardless of ethnic background,” the researchers noted. “These findings suggest that choroidal thinning may serve as a key driver in the pathogenesis of type 3 MNV. In particular, not all patients with type 3 MNV exhibit a thin choroid; in such cases, alternative pathogenic mechanisms may play a more prominent role in disease development.”Given that reticular pseudodrusen typically occurs in elderly individuals, its lower prevalence in Asians may be partially attributed to their younger age. However, this finding also suggests that type 3 MNV in Asians could be involved in a pathogenic process less closely associated with reticular pseudodrusen.The team suggested that studying individuals who have relocated between regions, such as Caucasians living in Asia or vice versa, would provide valuable insights to disentangle the interplay between genetic factors and environmental exposures.“These findings suggest that while type 3 MNV may share common pathophysiological mechanisms across ethnicities, the contributing factors may differ in certain respects,” they concluded.Click here for the journal source. Forte P, Fontana V, Park SM, et al. Ethnic differences in the presentation patterns of type 3 macular neovascularization. June 9, 2026. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.