What is the management of Epiretinal Membrane (ERM)?

Management of Epiretinal Membrane

The majority of ERMs should be observed without treatment, as they remain stable in most patients, with vitrectomy surgery reserved for those with significant visual impairment or bothersome symptoms affecting daily activities like reading or driving. 1

Initial Management Strategy: Observation

• Most ERMs (approximately 70%) remain stable or regress over time and do not require intervention. 1
• Only 29% of ERMs progress over 5 years, while 26% regress and 39% remain unchanged. 1
• Visual acuity typically remains stable over mean follow-up periods of 18-38 months in observational studies. 1

Patient Education During Observation

• Patients must be counseled that observation is appropriate for stable disease and that successful surgical options exist if symptoms worsen. 1
• Instruct patients to perform monocular Amsler grid testing regularly to detect progression, specifically watching for increasing metamorphopsia or development of central scotomas. 1
• Educate patients that spontaneous visual improvement rarely occurs, but worsening warrants surgical consideration. 1

Indications for Surgical Intervention

Surgery should be offered when patients experience decreased visual acuity (typically 20/50 or worse), significant metamorphopsia, diplopia, or difficulty using both eyes together that impairs activities of daily living. 1

Specific Surgical Criteria

• The decision is primarily symptom-driven rather than based solely on visual acuity measurements. 1
• Ask specifically about impairments in reading ability and driving capacity, as these functional limitations guide surgical timing. 1
• Eyes with complete loss of foveal contour on OCT progress to surgery more rapidly (16-17% by 6-7 years) compared to those with normal foveal contour (5% by 5.5 years). 2

Poor Prognostic Indicators for Conservative Management

• VMT broader than 1500 μm rarely improves without surgery. 1
• Accompanying pathologic macular detachment indicates need for surgical intervention. 1
• Poor presenting visual acuity suggests limited benefit from observation. 1

Surgical Management: Vitrectomy

Pars plana vitrectomy with membrane peeling is the definitive treatment, with approximately 80% of patients improving by at least 2 lines of visual acuity postoperatively. 1

Surgical Technique Considerations

• Internal limiting membrane (ILM) peeling should be performed in addition to ERM removal to reduce recurrence risk. 3
• ILM peeling is the only factor proven to prevent ERM recurrence (adjusted odds ratio = 0.33). 3
• The overall recurrence rate is 5%, with only 2% requiring reoperation when ILM peeling is performed. 3

Surgical Timing

• Surgery is elective, not urgent—delays are measured in months, not days. 1
• Earlier intervention may result in better long-term visual recovery compared to delayed surgery, though the evidence quality is limited. 1

Alternative Pharmacologic Management: Ocriplasmin

Ocriplasmin (FDA-approved intravitreal injection) can be considered for symptomatic vitreomacular adhesion, but works best in highly selected patients. 1

Optimal Candidate Characteristics for Ocriplasmin

• Age younger than 65 years 1
• Absence of ERM (ocriplasmin is less effective when ERM is present) 1
• Focal VMA of 1500 μm or less 1
• Phakic eyes 1
• Full-thickness macular hole with associated VMA 1

Important Caveat

• For patients with VMT ≤1500 μm, 30-40% experience spontaneous release of traction over 1-2 years, which typically results in visual improvement. 1
• This natural history should be discussed when considering ocriplasmin versus observation.

Risk-Benefit Discussion

• Cataract formation is the most common surgical complication and should be explicitly discussed during informed consent. 1
• The surgery carries standard vitrectomy risks, but functional outcomes are generally favorable. 1
• Patients must understand that postoperative rehabilitation is prolonged, and some may experience persistent symptoms despite successful membrane removal. 4

Diagnostic Monitoring

• Spectral-domain OCT is the standard imaging modality for diagnosis, characterization, and monitoring of ERM progression. 1
• Fluorescein angiography may be useful to exclude other macular pathologies (diabetic retinopathy, vein occlusion, choroidal neovascularization) but is not routinely required for ERM management. 1