Non-Exudative Macular Neovascularization: A 2-Year Follow-up Study Assessing the Progression of Retinal Pigment Epithelium and Outer Retinal Atrophy

INTRODUCTION: Advanced age-related macular degeneration (AMD) includes exudative and atrophic phenotypes. Non-exudative macular neovascularization (NE-MNV) has been linked to smaller areas of geographic atrophy (GA), suggesting it may slow the progression of complete retinal pigment epithelium and outer retinal atrophy (cRORA). This study aims to determine whether NE-MNV affects the prevalence and progression of cRORA over two years. METHODS: This observational study included 65 patients with unilateral exudative AMD, assessing 2-year cRORA progression and exudative conversion in the fellow eye. Patients were grouped based on the presence (NE-MNV) or absence (no NE-MNV) of NE-MNV. The prevalence and progression of tomographic cRORA, GA on fundus autofluorescence (FAF), cRORA greatest linear diameter (GLD), GA area, and exudative conversion rates were compared. RESULTS: Sixty-five patients were included in our cohort. The prevalence of NE-MNV was 24.6% (n=16). We identified a 33% bilateral exudative conversion rate (n=4) in the NE-MNV group and a 16.9% conversion rate in the eyes without NE-MNV (n=9) over the 2-year period (p=0.036). Eyes with NE-MNV had proportionally more frequent tomographic signs of atrophy (47.3% vs 31.3% in eyes without NE-MNV; p=0.535) and a smaller cRORA GLD (958.50±348 vs 2629.46±2124.72, p=0.008) compared to eyes without NE-MNV. cRORA was present in 11 eyes (30.6%) without NE-MNV and 2 eyes (12.5%) with NE-MNV (p=0.118). There were no significant differences in FAF GA prevalence (2 eyes out of 16 and 11 eyes out of 36, respectively; p=0.118) or GA area (p=0.186) or GA progression rate (p=0.125) between groups. CONCLUSION: In our study, the presence of NE-MNV was not associated with the prevalence of cRORA and/or FAF GA after a 2-year follow-up. Nonetheless, eyes with NE-MNV presented smaller cRORA GLD, corroborating that NE-MNV may prevent the progression of cRORA. One-third of the eyes with NE-MNV converted to exudative AMD over 2 years. Extended monitoring is required to confirm these results at long term.