Purpose: To investigate the association between foveal microvascular integrity and anti-vascular endothelial growth factor (VEGF) treatment response for diabetic macular edema (DME).
Methods: This retrospective study enrolled 58 eyes (from 45 patients) with DME. Treatment strategy was three to five monthly anti-VEGF injections followed by a PRN protocol. Treatment with an intravitreal corticosteroid would be considered for persistent DME after five consecutive anti-VEGF injections. Eyes achieving a treatment-free interval ≥ four months within two years were classified into the good clinical course group (group 1). Eyes with frequent recurrent edema (treatment-free interval < four months) or requiring an intravitreal corticosteroid within two years were classified into the suboptimal clinical course group (group 2). Foveal microvascular integrity was evaluated by two continuous variables, that is, vessel density (%) within a width of 300 µm around the foveal avascular zone (FD-300) on optical coherence tomography angiography (OCTA) and perifoveal leakage (area %) on fluorescein angiography (FA).
Results: There were 37 eyes in group 1 and 21 eyes in group 2. FD-300 (odds ratio 0.733, 95% CI 0.620-0.867, P < 0.001) and perifoveal leakage (odds ratio 1.064, 95% CI 1.007-1.124, P = 0.027) were significantly associated with suboptimal clinical course. Area under curve (AUC) was 0.820 for FD-300 and 0.723 for perifoveal leakage in predicting clinical course. FD-300 was negatively correlated with perifoveal leakage (coefficient = -0.325, P = 0.014).
Conclusions: Compromised foveal microvascular integrity, represented by lower FD-300 and more severe perifoveal fluorescein leakage, was associated with suboptimal clinical course in anti-VEGF treatment for DME. A negative correlation between FD-300 and perifoveal leakage existed.