Retinal vein changes in patients with high-risk proliferative diabetic retinopathy treated with conbercept and panretinal photocoagulation co-therapy: a cohort study

Abstract

ObjectiveThis study aimed to observe and compare retinal vein diameter changes and other essential indicators in patients with high-risk proliferative diabetic retinopathy (PDR) treated with intravitreal injection of conbercept (IVC) combined with panretinal photocoagulation (PRP) versus PRP monotherapy.MethodsA retrospective analysis was conducted on data from patients with high-risk PDR who received specific treatment and were followed up for 24 months. Among 82 patients with high-risk PDR, 50 eyes received PRP combined with IVC, whereas 32 eyes received PRP alone. During the 24-month follow-up period, changes in best-corrected visual acuity (BCVA), central foveal thickness (CFT), retinal vein diameter, number of microaneurysms (MA), neovascularization (NV) area, hard exudate (HE) area, size of the foveal avascular zone (FAZ), superficial capillary plexus (SCP) blood flow density, and adverse effects were recorded and compared between the two groups at baseline and at 6, 12, 18, and 24 months after treatment. The relationship between each observation index and vein diameter was also analyzed.ResultsDuring the 24-month follow up, significant improvements in the BCVA, CFT, retinal vein diameter, number of MAs, NV area, HE area, FAZ, and SCP were observed in the IVC+PRP group after treatment. The PRP group only showed significant reductions in NV and HE areas. The IVC+PRP group showed significant superiority over the PRP group in improving the vein diameter, number of MA, and HE area. However, no statistically significant difference in NV area reduction was found between the groups.ConclusionIn the treatment of high-risk PDR, IVC+PRP therapy has a significant advantage over PRP monotherapy. IVC+PRP therapy may reverse diabetes-induced retinal vein changes, restoring morphology and function.

Regression of Neovascularization after Panretinal Photocoagulation Combined with Anti-VEGF Injection for Proliferative Diabetic Retinopathy—A Review

“…The long-term follow-up studies used more than one or two intravitreal injections in cases without NV regression or in cases of NV relapse throughout the study. In all these studies, a necessity for the continuation of intravitreal treatment after the application of initial doses was indicated [ 41 , 42 , 43 , 45 , 46 , 47 , 48 ]. These findings indicate that total regression of NV cannot be obtained with only a small number of anti-VEGF injections.…”

“…One study reported improvements in the condition of the ellipsoid zone and external limiting membrane among the PRP plus IVR and IVR monotherapy groups [ 43 ]. The recent study by Si et al [ 48 ] evaluated changes in angio-OCT vascular parameters after PRP plus and PRP treatments. The foveal avascular zone area and number of microaneurysms decreased more, and the vessel density of the superficial capillary plexus significantly increased in the combination group.…”

“…The studies comparing PRP alone with PRP plus anti-VEGF therapy showed greater reduction of the NV area with combination therapy [27,28,[30][31][32][33][35][36][37]39,40,44,47]. Conversely, in the recent retrospective study by Si et al [48], such an advantage of combination treatment over PRP alone was not proven within the 24-month follow-up. Regarding the strength and durability of combination treatment in terms of the treatment schedule and duration of follow-up, early studies [27][28][29][30] utilized only a few months of follow-up and one or two intravitreal injections.…”