Choroidal thickness changes stratified by outcome in real-world treatment of diabetic macular edema.

Purpose: The aim of this study was to evaluate subfoveal choroidal thickness (SFCT) as a marker of outcome in real-world treatment of diabetic macular edema (DME) and to correlate it with choroidal thicknesses (CT) collected around the fovea.

Methods: Prospective interventional case series included a total of 126 eyes from 126 patients with recently diagnosed DME treated with a 3-monthly loading dose of ranibizumab or aflibercept and PRN thereafter until 24 months (M). CT was manually measured in the central 3500 μm area, subfoveally (SFCT), at 1750 μm right and left from the center in the horizontal plane and at 1750 μm up and down from the center in the vertical plane, by OCT. Anatomic (10% decrease in central retinal thickness) and functional (gain ≥ 5 letters) responses were assessed using univariate and multivariate analyses. The areas under ROC curves were used to assess whether baseline SFCT was a predictor of outcome.

Results: CT significantly decreased in all follow-ups (3 months after the 3 injections' loading dose (3M), 6 months (6M), 12 months (12M), 18 months (18M), 24 months (24M)). SFCT and other CT parameters are correlated. SFCT decrease from baseline was related with treatment (p = 0.003 to p < 0.001) but not with anatomic (3M, p = 0.858; 6M p = 0.762) or functional response (3M, p = 0.746; 6M, p = 0.156). SFCT was not found to be predictive of anatomic (AUC = 0.575, p = 0.172) or functional (AUC = 0.515, p = 0.779) outcome.

Conclusions: SFCT is a reliable marker of choroidal thickness. Baseline SFCT decreased with anti-VEGF treatment but did not predict DME outcome.