Wei Yong Team from Eye Hospital of Wenzhou Medical University Pioneers Laser-Free Surgical Model for BRVO with Vitreous Hemorrhage

Background

Branch retinal vein occlusion (BRVO) occurs when a branch of the central retinal vein becomes blocked, which can lead to leakage, abnormal blood vessel growth, and bleeding into the vitreous cavity, known as vitreous hemorrhage (VH). This can significantly impair vision. Standard surgical management often involves vitrectomy to remove the opaque vitreous and clear the hemorrhage, frequently followed by sectoral retinal laser photocoagulation to address ischemic areas or reduce the drive for neovascularization.

Since 2019, the team led by Yong Wei at the Affiliated Eye Hospital of Wenzhou Medical University has conducted specialized clinical research on BRVO combined with VH. They developed an innovative approach using intraoperative anti-VEGF medication and questioned whether it could serve as an alternative to traditional laser treatment.

What was achieved

The team conducted what is reported as the world's first prospective randomized controlled trial on this topic. The study enrolled 32 patients with BRVO complicated by VH, who were randomized 1:1 into two groups of 16 patients each after vitrectomy. One group received an intraoperative intravitreal injection of 0.5 mg ranibizumab, while the other underwent sectoral retinal laser photocoagulation. Patients were followed at intervals of 1 week, 1 month, 3 months, 6 months, and 12 months.

Results published in the Q1 ophthalmology journal Ophthalmology Science (with Wei Lin as first author and Yong Wei as corresponding author) showed that the anti-VEGF group had significantly better visual field mean deviation at 12 months compared to the laser group (P<0.01). Visual acuity improved in both groups. Vitreous hemorrhage recurrence was 12.5% in the anti-VEGF group versus 25% in the laser group, and postoperative macular edema rates were 18.8% versus 25%, though these differences were not statistically significant. The study also provided new insights into rebleeding mechanisms, noting better development of collateral vessels in the anti-VEGF group without destruction of original vascular structures.

How it works

In BRVO with VH, a blockage in a retinal vein increases pressure upstream, promoting fragile new vessels or leakage that can bleed into the vitreous, obscuring vision. Vitrectomy surgery removes the vitreous gel and blood to clear the visual axis. Conventionally, surgeons then apply laser photocoagulation to parts of the retina to decrease oxygen demand or ablate ischemic zones, aiming to prevent further neovascularization.

In the new model pioneered by the team, instead of laser burns, an anti-VEGF drug such as ranibizumab is injected into the eye at the end of the vitrectomy. Anti-VEGF agents inhibit vascular endothelial growth factor, a protein that stimulates abnormal vessel growth and leakage. This approach supports the natural formation and expansion of collateral vessels that bypass the occluded vein, improving blood flow without thermally damaging retinal tissue. The study observed that laser application could disrupt potential collateral pathways and contribute to venous macroaneurysms in some cases, which were linked to recurrent bleeding. By preserving native vascular architecture, the anti-VEGF strategy reduces permanent visual field defects while addressing neovascularization.

What it means for international patients

The Affiliated Eye Hospital of Wenzhou Medical University has an established program for international patients, recording 2444 overseas patient visits in 2025 from countries including Germany, Iraq, Canada, and others. The hospital maintains an international cooperation and exchange department and provides bilingual support services, including dedicated high-level guides trained to assist foreign patients with language and navigation.

This research offers a potential new surgical option for suitable cases of BRVO with vitreous hemorrhage. International patients considering care at the hospital for this or related retinal conditions should contact the facility directly to confirm current availability, eligibility criteria, and individual suitability, as treatment decisions depend on specific clinical factors.

About the hospital

The Affiliated Eye Hospital of Wenzhou Medical University, also known as the Eye Hospital of Wenzhou Medical University, is located in Wenzhou, Zhejiang Province, China. Founded in 1998, it is a specialized tertiary hospital affiliated with Wenzhou Medical University and forms part of the National Clinical Research Center for Ocular Diseases. The hospital integrates clinical care, research, education, and training with a focus on ophthalmology and optometry.

It is recognized for expertise in vitreoretinal microsurgery and the management of complex fundus conditions, including retinal detachment, macular diseases, diabetic retinopathy, ocular trauma, and intraocular tumors. The Yong Wei team has reported high one-time retinal reattachment rates and macular hole closure rates in their practice. The hospital operates an English-language website and has infrastructure to support international patients through its international cooperation department.