Early Vitrectomy vs PRP in Early Proliferative Diabetic Retinopathy

Comparison of Early Micro-invasive Vitrectomy Surgery Versus Panretinal Photocoagulation for the Treatment of Early Proliferative Diabetic Retinopathy: A Multi-center Randomized Trial

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

Study Overview

• Status: Recruiting
• Conditions: Proliferative Diabetic Retinopathy (PDR)
• Intervention / Treatment: Procedure: Microincision Vitrectomy Surgery; Procedure: Panretinal Photocoagulation

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: xiuju Chen, md; Phone Number: +8618060955810; Email: joyychen@aliyun.com
• Study Contact Backup: Name: wenjie huang; Phone Number: +8618150139807; Email: xmykec@huaxiaeye.com

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China
      • Completed
      • Peking University People's Hospital
  • Fujian
    • Xiamen, Fujian, China, 361000
      • Recruiting
      • Xiamen Eye Center of Xiamen University
      • Contact: Xiuju Chen, MD; Phone Number: 15121013344; Email: joyychen@aliyun.com
      • Principal Investigator: Xiaoxin Li, PhD
  • Henan
    • Zhengzhou, Henan, China
      • Completed
      • Henan Province People's Hospital
  • Jiangsu
    • Nanjing, Jiangsu, China
      • Completed
      • Jiangsu Provincial People's Hospital
    • Nanjing, Jiangsu, China
      • Completed
      • Nanjing Medical University affiliated Eye Hospital
  • Liaoning
    • Dalian, Liaoning, China
      • Completed
      • The First Affiliated Hospital of Dalian Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18 years or older.

Diagnosis of type 2 diabetes mellitus.

Presence of early proliferative diabetic retinopathy with active neovascularization, or mild vitreous hemorrhage or preretinal hemorrhage that does not interfere with evaluation of neovascularization.

Relatively clear optical media, good pupillary dilation, and sufficient cooperation for panretinal photocoagulation and retinal imaging.

Ability and willingness to provide written informed consent.

If both eyes are eligible, the eye with worse vision will be included.

Exclusion Criteria:

• Prior panretinal photocoagulation, macular photocoagulation, or vitrectomy in the study eye.

Retinal traction or retinal detachment.

Optic neuropathy.

Macular edema caused by reasons other than diabetes.

Coexisting ocular disease that may decrease visual acuity during the study.

Substantial cataract likely to decrease visual acuity by more than three lines.

Major ocular surgery within the past 4 months or planned intraocular surgery within the next 6 months.

YAG capsulotomy within the past 2 months.

Any intravitreal injection within the past 3 months.

Aphakia.

Severe external ocular infection.

Uncontrolled glaucoma.

Significant renal disease requiring dialysis or kidney transplantation.

Unstable glycemic control.

Blood pressure greater than 180/110 mmHg.

History of transient ischemic attack, stroke, myocardial infarction, acute congestive heart failure, or other acute cardiac event requiring hospitalization within the past 4 months.

Pregnant, lactating, or intending to become pregnant during the study period.

Participation in another clinical trial.

Unwilling or unable to provide informed consent, undergo randomization, or return for scheduled visits.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Microincision Vitrectomy Surgery; Participants undergo early microincision vitrectomy surgery (MIVS) using small-gauge instrumentation (25G or 27G) with high-speed vitreous removal. During surgery, scattered photocoagulation is applied to the far peripheral retina.	Procedure: Microincision Vitrectomy Surgery; Panretinal photocoagulation delivered using standard laser therapy, consisting of approximately 1000 to 1500 laser burns applied over one or two sessions according to routine clinical practice.; Other Names: Panretinal Photocoagulation
Active Comparator: Panretinal Photocoagulation; Participants receive standard panretinal photocoagulation (PRP) according to routine clinical practice. Treatment consists of approximately 1000 to 1500 laser burns delivered over one or two sessions within several weeks after randomization.	Procedure: Panretinal Photocoagulation; Panretinal photocoagulation delivered using standard laser therapy, consisting of approximately 1000 to 1500 laser burns applied over one or two sessions according to routine clinical practice.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of Eyes With Complete Regression of Neovascularization	Complete regression is defined as absence of neovascularization at the disc or neovascularization elsewhere in the retina, assessed by fundus fluorescein angiography or optical coherence tomography angiography.	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of Eyes With Partial Regression of Neovascularization	Partial regression is defined as reduction in retinal neovascularization compared with baseline, assessed by fundus fluorescein angiography or optical coherence tomography angiography.	12 months
Incidence of Vitreous Hemorrhage	Incidence of vitreous hemorrhage through 6/12 months after treatment.	6 months；12 months
Change in Visual Field	Change in visual field cumulative values measured using the 60-degree visual field test.	Baseline to 12 months
Change in Best Corrected Visual Acuity	Change in best corrected visual acuity measured using an ETDRS LogMAR chart.	Baseline to 12 months

Collaborators and Investigators

• Sponsor: Xiamen Ophthalmology Center Affiliated to Xiamen University
• Collaborators: Peking University People's Hospital; Henan Provincial People's Hospital; Nanjing Medical University; The First Affiliated Hospital of Dalian Medical University; Jiangsu Provincial People's Hospital
• Investigators: Principal Investigator: Xiaoxin Li, PhD, Xiamen Eye Center of Xiamen University

Publications and helpful links

General Publications

• Fundus photographic risk factors for progression of diabetic retinopathy. ETDRS report number 12. Early Treatment Diabetic Retinopathy Study Research Group. Ophthalmology. 1991 May;98(5 Suppl):823-33.
• Simpson AR, Dowell NG, Jackson TL, Tofts PS, Hughes EH. Measuring the effect of pars plana vitrectomy on vitreous oxygenation using magnetic resonance imaging. Invest Ophthalmol Vis Sci. 2013 Mar 21;54(3):2028-34. doi: 10.1167/iovs.12-11258.
• Jones CH, Gui W, Schumann RG, Boneva S, Lange CA, van Overdam K, Chui TY, Rosen RB, Engelbert M, Sebag J. Hyalocytes in proliferative vitreo-retinal diseases. Expert Rev Ophthalmol. 2022;17(4):263-280. doi: 10.1080/17469899.2022.2100764. Epub 2022 Sep 6.
• Vaz-Pereira S, Dansingani KK, Chen KC, Cooney MJ, Klancnik JM Jr, Engelbert M. TOMOGRAPHIC RELATIONSHIPS BETWEEN RETINAL NEOVASCULARIZATION AND THE POSTERIOR VITREOUS IN PROLIFERATIVE DIABETIC RETINOPATHY. Retina. 2017 Jul;37(7):1287-1296. doi: 10.1097/IAE.0000000000001336.
• Gawecki M, Kicinski K, Bianco L, Battaglia Parodi M. Regression of Neovascularization after Panretinal Photocoagulation Combined with Anti-VEGF Injection for Proliferative Diabetic Retinopathy-A Review. Diagnostics (Basel). 2023 Dec 22;14(1):31. doi: 10.3390/diagnostics14010031.
• Bahr TA, Bakri SJ. Update on the Management of Diabetic Retinopathy: Anti-VEGF Agents for the Prevention of Complications and Progression of Nonproliferative and Proliferative Retinopathy. Life (Basel). 2023 Apr 27;13(5):1098. doi: 10.3390/life13051098.
• Berrocal MH, Acaba-Berrocal L. Early pars plana vitrectomy for proliferative diabetic retinopathy: update and review of current literature. Curr Opin Ophthalmol. 2021 May 1;32(3):203-208. doi: 10.1097/ICU.0000000000000760.

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2025
• Primary Completion (Estimated): June 10, 2026
• Study Completion (Estimated): June 10, 2026

Study Registration Dates

• First Submitted: May 7, 2026
• First Submitted That Met QC Criteria: May 7, 2026
• First Posted (Actual): May 14, 2026

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 7, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Vitrectomy; Retinal neovascularization; Proliferative diabetic retinopathy; Panretinal photocoagulation
• Additional Relevant MeSH Terms: Pathologic Processes; Eye Diseases; Retinal Diseases; Metaplasia; Neovascularization, Pathologic; Pathological Conditions, Signs and Symptoms; Retinal Neovascularization
• Other Study ID Numbers: XMYKZX-KY-2024-061; IIT-92241613 (Other Grant/Funding Number: Alcon)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be publicly available but may be shared upon reasonable request and with approval from the study sponsor and institutional review board.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No