Ethnic comparison of MacTel over 5 years follow up

To compare long-term structural disease progression in type 2 macular telangiectasia (MacTel) between Indian and Caucasian populations using a novel optical coherence tomography-based staging system structured around retinal layer involvement.

This retrospective, observational, dual-center cohort study included 49 eyes from 30 Caucasian and 109 eyes from 55 Indian patients with type 2 MacTel. All patients had a minimum of 5 years follow-up. Disease severity was staged as early, intermediate, or advanced based on predefined OCT features involving the inner retina, outer retina, and presence of neovascularization. Progression was defined as a shift to a higher stage. Kaplan-Meier survival analysis, log-rank test, and Cox proportional hazard models were used to evaluate progression and associated risk factors.

At baseline, both groups had similar stage distributions (p = 0.451). Over the follow-up period, 82% of Caucasian and 81% of Indian eyes showed no disease progression. Median time to progress from early to intermediate stage was 32 months in Caucasians and 36 months in Indians (p = 0.847). Progression to advanced stage occurred after 51 and 69.5 months, respectively (p = 0.497). Survival analysis showed no significant differences in progression based on gender, ethnicity, or diabetes mellitus status.

Structural progression in type 2 MacTel is slow and comparable across Caucasian and Indian cohorts over long-term follow up. Further studies to compare the influence of systemic and environmental conditions across different ethnicities will help understand pathogenesis of MacTel.