Retinal and choroidal morphometric analysis in fellow eye of unilateral wet age related macular degeneration using optical coherence tomography angiography.

BACKGROUND

Age-related macular degeneration (AMD) when associated with macular neovascularization can cause severe visual morbidity. This study aims to evaluate the retinal and choroidal microvascular alterations using optical coherence tomography angiography (OCTA) in eyes with unilateral wet age-related macular degeneration (AMD) termed as "affected eye" (AE) and compare it with their "fellow eyes" (FE).

METHODS

This cross-sectional study included 60 patients (120 eyes) with age over 50 years. Vessel density (VD), perfusion density (PD), and foveal avascular zone (FAZ) in the superficial capillary plexuses (SCP), deep capillary plexus (DCP) and avascular slab were assessed using OCTA. Enhanced depth imaging was used to evaluate subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI).

RESULTS

The mean age was 73.9 ± 9.54 years (51-89 years) with 51.7% male. Quantitative OCTA analysis showed no significant inter-eye differences in VD or PD in SCP or DCP (p > 0.05). However, FAZ was significantly enlarged in AE compared with FE in SCP (0.91 ± 0.40 vs. 0.64 ± 0.20 mm²; p < 0.001) and DCP (p < 0.001). FAZ enlargement in the avascular slab was not statistically significant (p 0.20). Pattern I macular neovascularization (MNV) was significantly associated with the shape (p 0.026), presence of anastomoses (p 0.029), and overall activity scores (p 0.001). Inter-eye differences choroidal parameters were statistically significant for SFCT (p 0.019), haller layer (p 0.014) and CVI (p < 0.001). AE status was significantly associated with age (p 0.04) smoking (p 0.01), and lens status (p 0.05).

CONCLUSION

FAZ enlargement demonstrated greater inter-eye separation and higher discriminatory performance compared than density-based OCTA parameters and may reflect localized microvascular or structural alteration in unilateral neovascular AMD. OCTA-based assessment of FE may aid in detecting early microvascular alterations and guiding timely intervention, which may be potentiated by retinal and choroidal vascular or structural remodeling.