Early Vitrectomy vs PRP in Early Proliferative Diabetic Retinopathy

Overview

The goal of this clinical trial is to learn whether early microincision vitrectomy surgery (MIVS) can improve retinal neovascularization outcomes compared to standard pan-retinal photocoagulation (PRP) in patients with early proliferative diabetic retinopathy (PDR). It will also evaluate the safety and functional outcomes of early surgical intervention in this population. The main questions it aims to answer are: Does early MIVS increase the proportion of eyes achieving complete regression of retinal neovascularization at 12 months? Does early MIVS improve visual and functional outcomes, including visual acuity and visual field, compared to PRP? Researchers will compare early MIVS combined with peripheral scatter photocoagulation to standard PRP to determine whether early surgical intervention leads to better regression of neovascularization and improved clinical outcomes. Participants will: Receive either MIVS with peripheral photocoagulation or standard PRP Undergo retinal imaging assessments including fundus fluorescein angiography (FFA) or optical coherence tomography angiography (OCTA) Complete follow-up visits over 12 months, including visual acuity testing, visual field testing, and optical coherence tomography (OCT) imaging Be monitored for the occurrence of vitreous hemorrhage and other clinical outcomes

Diabetic retinopathy is a leading cause of vision impairment worldwide, particularly among working-age adults. The development of retinal neovascularization in proliferative diabetic retinopathy (PDR), including neovascularization at the disc (NVD) and neovascularization elsewhere (NVE), is associated with a high risk of vitreous hemorrhage, tractional retinal detachment, and severe vision loss. Current standard treatment for early PDR includes panretinal photocoagulation (PRP) with or without adjunctive anti-vascular endothelial growth factor (anti-VEGF) therapy. While PRP has been shown to reduce the risk of severe vision loss, it is associated with several limitations, including peripheral visual field loss, reduced night vision, exacerbation of macular edema, and incomplete regression of neovascularization in a substantial proportion of patients. Anti-VEGF therapy requires repeated intravitreal injections and may be associated with treatment burden and variable response. The vitreous body plays an important role in the pathophysiology of PDR by providing a scaffold for neovascular growth and contributing to the persistence of vascular endothelial growth factor (VEGF) within the vitreous cavity. Microincision vitrectomy surgery (MIVS) may offer potential therapeutic advantages by removing the vitreous scaffold, facilitating the clearance of VEGF, and improving intraocular oxygenation. These mechanisms may contribute to more effective regression of retinal neovascularization and reduction in disease progression. This study is a multicenter, prospective trial designed to compare early MIVS intervention with standard PRP in patients with early PDR. Eligible participants will receive either MIVS combined with peripheral photocoagulation or standard PRP. The surgical procedure will be performed using small-gauge (25G or 27G) instrumentation with high-speed vitreous removal. In the experimental group, scattered photocoagulation will be applied to the far peripheral retina during surgery. In the control group, PRP will be delivered in accordance with standard clinical practice over multiple sessions. Participants will undergo standardized follow-up evaluations over 12 months. Retinal neovascularization will be assessed using fundus fluorescein angiography (FFA) or optical coherence tomography angiography (OCTA). Functional outcomes, including best corrected visual acuity (BCVA) and visual field cumulated values , will be measured using standardized protocols. Structural outcomes such as central retinal thickness will be assessed by optical coherence tomography (OCT). To enhance the reliability of outcome assessment, retinal imaging will be obtained using standardized acquisition protocols and evaluated by trained graders when feasible. This study aims to generate clinical evidence on whether early surgical intervention with MIVS can improve neovascular regression and functional outcomes compared with PRP alone in early PDR, thereby informing optimal treatment strategies for this patient population.