Epiretinal Membrane
- Feb 5
- 2 min read
Updated: Mar 4
An epiretinal membrane (also known as ERM) is a thin layer of fibrous tissue that forms on the surface of the retina, most often over the macula.
What causes it?
ERM is most commonly age-related, following normal vitreous separation. However, it can also develop after retinal surgery, inflammation, trauma, vascular disease, or retinal tears.
1. Idiopathic (most common)
Age-related (usually >50 years)
Associated with posterior vitreous detachment (PVD)
2. Secondary Causes
Retinal tears or detachments
Ocular trauma
Intraocular surgery (e.g., cataract surgery)
Uveitis
Diabetic retinopathy
Retinal vascular occlusions
What does it do?
As the membrane contracts, it can wrinkle or distort the underlying retina, affecting central vision. This can affect your vision.
Symptoms
Blurred or distorted vision (straight lines look wavy)
Reduced visual clarity or contrast
Sometimes no symptoms, especially when mild
Management
Observation, if vision is good and stable, and symptoms are mild, with regular follow ups for OCT (Optical Coherence Tomography - a scan technique that allows us to look at the layers of the retina and the membrane). If visual distortion becomes significant or if it progresses, then surgical membrane peeling (vitrectomy) may be done.
Surgery Indications
Since surgery comes with risks, in general it is only done if there is significant visual impairment, distressing metamorphopsia (distortion in vision, such as straight objects and lines becoming wavy), and progressive decline in vision. Surgery may be combined with ILM peeling to reduce possible recurrence.
Post-operatively, gradual visual improvement is expected over months, although visual recovery may be incomplete. There may be better prognosis if surgery performed before the macular (the centre portion of the retina responsible for central vision) is severely distorted.
Read more about Epi-Retinal Membrane here.
How does it happen? (A slightly more technical topic)
Microbreaks in the internal limiting membrane (ILM) layer of the retina causes migration and proliferation of glial cells, fibroblasts, and myofibroblasts. This forms a contractile membrane that can pull on the retina, thereby causing retinal wrinkling and distortion.
