Minimal Vitrectomy Surgery for Epiretinal Membrane

Idiopathic epiretinal membrane (ERM) is characterized by fibrocellular proliferation on the retinal surface, leading to macular edema, metamorphopsia, and visual impairment. Traditional treatment involves pars plana vitrectomy (PPV) with posterior vitreous detachment (PVD) induction and core vitrectomy, which may increase the risk of postoperative cataract.

Minimal Vitrectomy Surgery (MVS) is a modified surgical approach designed to minimize vitreous removal and preserve the hyaloid. The epiretinal membrane is directly peeled through the intact vitreous. If pre-existing vitreous floaters or membrane fragments remain after peeling and cannot be removed safely with micro-forceps, limited localized vitrectomy is selectively performed to eliminate these floaters and avoid postoperative visual disturbances.

This trial aims to evaluate the efficacy and safety of MVS compared to conventional vitrectomy, focusing on visual improvement, macular thickness, cataract progression, ERM recurrence, and intraoperative complications.

• Minimal Vitrectomy Surgery (Procedure): The epiretinal membrane is peeled directly through the intact vitreous. Limited localized vitrectomy is selectively performed if pre-existing floaters or membrane fragments remain after peeling.
• Conventional Vitrectomy (Procedure): Standard pars plana vitrectomy is performed with posterior vitreous detachment induction and core vitreous removal prior to epiretinal membrane peeling.

Primary outcomes

• Cataract progression assessed by LOCS III and DLI [Baseline, 12 months]: Cataract progression evaluated by Lens Opacities Classification System III (LOCS III) grading and Dysfunctional Lens Index (DLI) changes.

Secondary outcomes

• BCVA change from baseline to 12 months [Baseline, 1 week, 1 month, 3 months, 6 months, 12 months]: Change in best-corrected visual acuity (logMAR) from baseline to 12 months postoperatively.
• Change in central retinal thickness (CRT) by OCT [Baseline, 1 week, 1 month, 3 months, 6 months, 12 months]: Change in macular central retinal thickness as assessed by OCT.
• Epiretinal membrane recurrence rate [12 months]: Recurrence of epiretinal membrane at 12-month follow-up.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

1. Age ≥ 18 years.
2. Diagnosis of idiopathic epiretinal membrane (ERM) confirmed by clinical examination and OCT imaging.
3. Clear ocular media allowing adequate fundus imaging.
4. Phakic eye.
5. Ability and willingness to provide written informed consent.

Exclusion Criteria:

1. Prior cataract surgery or advanced cataract requiring combined surgery. Co-existing retinal diseases (e.g., diabetic retinopathy, retinal detachment, retinal vein occlusion).
2. Systemic conditions preventing safe surgery or follow-up.
3. History of prior ocular or periocular corticosteroid use, including intraocular injection, periocular injection, or long-term topical corticosteroid eye drops.

• Weihong Yu, MD, Principal investigator, Peking Union Medical College Hospital