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 naive 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.