From the Guidelines
An epiretinal membrane (ERM) is a thin, transparent layer of fibrous tissue that forms on the surface of the retina, specifically over the macula, which is responsible for central vision, and is characterized by fibrocellular proliferation on the surface of the neurosensory retina, with or without wrinkling of the retina, as described in the 2020 study by 1. This condition occurs when cells migrate onto the retinal surface and produce collagen, creating a membrane that can contract and wrinkle the retina beneath it.
Key Characteristics of ERMs
- ERMs are relatively common, especially in people over 50, and can be caused by aging, posterior vitreous detachment, eye inflammation, trauma, or previous eye surgeries.
- Many ERMs are mild and don't require treatment as they cause minimal symptoms.
- However, when symptoms develop, they typically include blurred or distorted central vision, straight lines appearing wavy, and difficulty reading or performing detailed tasks.
Treatment Options
- In more severe cases where vision is significantly affected, the recommended treatment is vitrectomy surgery, during which a retinal surgeon removes the membrane from the retina's surface, as supported by the 2020 study by 1.
- Recovery after surgery takes several months, with vision gradually improving over this period.
- Not all vision changes may resolve completely after surgery, especially if the ERM was present for a long time before treatment.
Risk Factors and Prevalence
- Risk factors for ERM include increasing age, other retinal pathologies, uveitis, retinal breaks, retinal vein occlusions, diabetic retinopathy, and ocular inflammatory diseases, as noted in the 2020 study by 1.
- The prevalence of ERM appears to vary by ethnicity, but the variations are not consistent across studies, as mentioned in the 2020 study by 1.
From the Research
Definition and Characteristics of Epiretinal Membrane
- An epiretinal membrane (ERM) is a condition where a layer of fibrous tissue forms on the surface of the retina, specifically on the internal limiting membrane [(2,3,4)].
- ERMs are avascular, meaning they do not contain blood vessels, and are composed of various cell types, including myofibroblasts, fibrocytes, and retinal pigment epithelial cells 5.
Symptoms and Effects
- Patients with ERMs may experience minor visual distortion, but in some cases, significant visual loss and metamorphopsia (distorted vision) can occur [(2,3)].
- The presence of ERMs can lead to macular pucker, a condition where the membrane contracts and causes the retina to wrinkle [(2,5)].
Treatment and Prognosis
- Treatment for ERMs typically involves surgical removal of the membrane, often through posterior vitrectomy and membrane peeling [(2,3,4)].
- The prognosis for visual recovery after surgery varies, with some patients experiencing significant improvement and others showing poor visual recovery 3.
- The appearance of the photoreceptor layer on spectral domain optical coherence tomography (SD-OCT) images has been found to be an important prognostic factor for visual recovery 3.
Prevalence and Associations
- ERMs are more commonly found in people over the age of 50, but can also occur in younger patients, often in association with other vitreoretinal diseases or following intraocular surgery [(2,4)].
- ERMs have been found to contain vascular endothelial growth factor (VEGF) and tumor necrosis factor alpha (TNF-alpha), which may play a role in the development and growth of the membrane 6.