Longitudinal neovascular changes on optical coherence tomography angiography in proliferative diabetic retinopathy treated with panretinal photocoagulation alone versus with intravitreal conbercept plus panretinal photocoagulation: a pilot study

Purpose To investigate the longitudinal changes in neovascularization of the retinal elsewhere (NVE) size on optical coherence tomography angiography (OCTA) in proliferative diabetic retinopathy (PDR) treated by panretinal photocoagulation (PRP) alone or by single intravitreal conbercept injection plus PRP. Methods A prospective pilot study. Forty-four PDR eyes with NVE confirmed by fundus fluorescein angiography (FFA) and OCTA were included. They were assigned to receive PRP alone (PRP group) or intravitreal conbercept injection plus PRP (combination group). Ophthalmic examinations, including BCVA and OCTA to measure the NVE size, were performed at baseline before each PRP session, and at 1, 3, and 6 months. Results Twenty-nine eyes were included in the PRP group, and 15 eyes were included in the combination group. There was no significant difference between the two groups with respect to age, BCVA, and NVE area at baseline. In both groups, there was a significant (P < 0.05) NVE size reduction during the majority of study visits, with the reduction observed in the combination group significantly larger than that in the PRP group. No significant BCVA changes were observed in either groups, except that in the PRP group, the BCVA at 3 months was significantly improved (P < 0.05). No deaths or unexpected adverse events (AEs) were reported. Conclusions Intravitreal conbercept plus PRP was more effective than PRP monotherapy in NVE regression. Precise quantification of the NVE area by OCTA makes it a useful tool for monitoring the response of retinal neovascular lesions to the therapy.