Early Choriocapillaris Dysfunction in Fellow Eyes of Patients with Unilateral Neovascular Age-Related Macular Degeneration

Purpose: To investigate early changes in AMD by evaluating and comparing choriocapillaris (CC) flow in fellow eyes of patients with unilateral neovascular age-related macular degeneration (nAMD) and in healthy controls using swept-source optical coherence tomography angiography (SS-OCTA). Methods: Patients with unilateral nAMD and no/early/intermediate AMD (no/e/iAMD) in their fellow eye and normal controls who underwent SS-OCT and OCTA where included. CC perfusion was assessed on MATLAB as percentage of flow deficits (FD%) in the central 4.5 x 4.5 mm macular region, after removing artifacts. Results: 81 eyes/patients (22 eyes with noAMD, 30 with eAMD, 29 with iAMD) with unilateral nAMD and 24 controls were analyzed. Median FD% was 8.97 (IQR 8.58-9.53) in AMD group, 8.92 (IQR 8.64-9.27) in noAMD group, 8.96 (IQR 8.46-9.38) in eAMD group, 9.05 (IQR 8.58-9.8) in iAMD group, and 8.22 (IQR 7.78-8.55) in controls. A statistically significant difference in FD% was observed between controls and AMD group (p < 0.001), as well as between each AMD subgroup and controls (noAMD vs controls p = 0.0037; eAMD vs control p = 0.0012; iAMD vs controls p = 0.0002). Conclusion: This study suggests that CC dysfunction may occur in fellow eyes of patients with unilateral nAMD before visible AMD signs, potentially preceding RPE changes. Further longitudinal studies are needed to confirm these findings and explore the correlation with AMD development/progression.