Impact of Intravitreal Anti-VEGF Therapy on Microperimetry of the Retinal Nonperfusion Areas of Patients with Proliferative Diabetic Retinopathy

Introduction: This study assessed retinal nonperfusion area (NPA) changes after anti-VEGF treatment in proliferative diabetic retinopathy (PDR) eyes using swept-source widefield optical coherence tomography angiography (SS-WF OCTA) and investigated the relationships with the microperimetry (MP-1) functional changes observed in the same areas. Methods: This was a single-center observational case series. Seven PDR eyes naïve to treatment that received three monthly intravitreal injections of aflibercept were included. All eyes were imaged with SS-WF OCTA and MP-1 at baseline (T0) and 1 month after the third injection (T1). The regions of interest (ROIs) with evidence of NPAs at T0 OCTA images were selected. Qualitative and quantitative [perfusion density (PD) and vessel length density (VLD)] OCTA vascular changes in the selected ROIs between T0 and T1 were compared with the corresponding MP-1 functional changes [mean sensitivity (MS)]. Results: Twenty-five ROIs were selected. In 52% of the ROIs, an improvement in MS was observed at T1, which was associated with qualitative and quantitative improvement in 92.3% of NPAs by OCTA. In 32% of the ROIs, MS worsening was observed at T1, which was associated with qualitative and quantitative worsening in 75% of NPAs by OCTA. Positive correlations between MS and both PD and VLD were found. Fisher’s test showed an association between the improvements in MP and VLD. Conclusions: An association between OCTA and MP-1 parameter changes was found. The concomitant functional and morphological improvement in half of the ROIs suggests that anti-VEGF treatment may promote retinal changes that result in a better functional response.