Non-exudative macular neovascularization: a 3-year follow-up study assessing the progression for exudative or atrophic stages.

INTRODUCTION

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 to later stages of age-related macular degeneration (AMD) over 3 years in the fellow eyes of patients with unilateral exudative AMD.

METHODS

Observational study including 61 patients with unilateral exudative AMD assessing 3-year cRORA progression and exudative conversion in the fellow eye. Patients were grouped based on the presence (NE-MNV) or absence of NE-MNV (no NE-MNV). The prevalence and progression of tomographic cRORA, GA on fundus autofluorescence (FAF) and exudative conversion rates were compared.

RESULTS

Sixty-one patients were included in our cohort. The prevalence of NE-MNV was 24.6%. We identified a 36.3% bilateral exudative conversion rate (n = 4) in the NE-MNV group and a 15.2% conversion rate in the eyes without NE-MNV (n = 7) at 3 years (p = 0.036). There were no significant differences in cRORA or FAF GA prevalence between groups (2/15 (13.3%) with NE-MNV vs. 11/35 (31.4%) without NE-MNV, p = 0.410). Eyes with NE-MNV presented a significantly smaller cRORA greatest linear diameter (GLD) than eyes without NE-MNV (1342.3 ± 1260 vs. 2897 ± 1925.3, p = 0.023), and a smaller FAF GA area (4.5 ± 3.7 vs. 11.9 ± 10.6 mm2, p = 0.042). The presence of reticular pseudodrusen and hypertransmission defects were significantly associated with the GA phenotype (p = 0.002 and p < 0.001, respectively) while the identification of concurrent large drusen was significantly associated with the presence of MNV, both exudative and non-exudative (p = 0.023). The increase in OCTA NE-MNV area and the presence of anastomosis and loops pattern were associated with exudative conversion (p = 0.046 and p = 0.032, respectively).

CONCLUSION

The presence of NE-MNV was associated with smaller cRORA GLD and FAF GA area, corroborating that NE-MNV may prevent the progression of cRORA. One third of the eyes with NE-MNV converted to exudative AMD over 3-years. Reticular pseudodrusen, hypertransmission defects and concurrent large drusen were significant OCT biomarkers for late stages AMD. Extended monitoring is required to confirm these results at long term.