Outer nuclear layer recovery as a predictor of visual prognosis in type 1 choroidal neovascularisation of neovascular age-related macular degeneration

Abstract Objectives To investigate the changes in outer nuclear layer (ONL) thickness during anti-vascular endothelial growth factor (VEGF) treatment in type 1 choroidal neovascularisation (CNV) and its impact on vision. Methods Type 1 CNV eyes (n = 94) were retrospectively compared to normal control eyes (n = 35). Along with best-corrected visual acuity (BCVA), the location of CNV, foveal ONL thickness, and subretinal fluid height were measured using optical coherence tomography (OCT) and analysed. The type 1 CNV eyes group was subdivided into two groups based on ONL thickness changes during the initial three aflibercept loading doses. Visual outcome and OCT biomarkers were compared. Results The CNV group had thinner foveal ONL and worse BCVA compared to the control group. ONL thickness recovered partially along with visual improvement following aflibercept injections. Foveal ONL improvement correlated with the final BCVA during the 1-year follow-up. The study group was subsequently divided into two subgroups, based on the difference in foveal ONL thickness at baseline and after three loading doses of aflibercept: the poor response group (ONL change < + 10 µm; group A) and the good response group (ONL change ≥ +10 µm; group B). Group B showed better visual outcomes than group A, which had more subfoveal CNV (76.0%) than group B (45.5%, p = 0.012). Conclusions Type 1 CNV eyes that recovered following anti-VEGF treatment demonstrated good final visual outcome during the 1-year follow-up. Monitoring the foveal ONL thickness during early anti-VEGF treatment could predict visual outcomes in type 1 CNV patients.