Choroidal imaging biomarkers as predictors of conversion to exudative age-related macular degeneration

Purpose Predicting the progression of intermediate AMD (iAMD) to neovascular AMD (nAMD) will help to identify high-risk patients and improve treatment outcomes. The present study assessed whether choroidal OCT biomarkers could predict conversion to nAMD. Methods This retrospective study included patients with clinically stable iAMD who either converted to nAMD (C group) or did not convert (NC group) during one year of follow-up. OCT parameters included subfoveal choroidal thickness (SFCT), central macular thickness (CMT), Haller vascular thickness (HVT), inner choroidal thickness (ICT), and double-layer sign (DLS). Results Of 116 total eyes, there were 37 in the NC group and 79 in the C group. Baseline SFCT was significantly lower in the C group compared to the NC group (169.0 +/- 63.2 mu m vs. 218.0 +/- 97.8 mu m, p = 0.01). Baseline HVT and ICT were lower in the C group (105.2 +/- 40.6 mu m vs. 121.0 +/- 56.6 mu m, p = 0.17 and 61.9 +/- 35.5 mu m vs. 77.5 +/- 41.7 mu m, p = 0.09). HVT was decreased at all time points in the C group vs NC (p > 0.05). The ICT was reduced in the C group at each time point except at conversion time (p > 0.05). Of all eight eyes who presented DLS at baseline, 100% converted to nAMD (p < 0.001). Conclusion Lower SFCT at baseline may signal conversion to nAMD within 12 months.