An epiretinal membrane (ERM) — also called macular pucker or cellophane maculopathy — is a thin layer of scar-like tissue that forms over the macula, the centre of the retina. As it contracts it wrinkles the retina beneath, blurring central vision and making straight lines look wavy or bent (distortion). Many membranes are mild and simply monitored; when they significantly affect reading or daily vision, a keyhole operation called vitrectomy with membrane peel — from £6,100 per eye — removes the membrane.
What is an epiretinal membrane?
The macula is the small central part of the retina that gives you sharp, detailed vision for reading and recognising faces. An epiretinal membrane is a fine sheet of cells that grows across its surface. On its own a thin membrane may cause no trouble, but if it contracts it puckers the underlying retina — hence the name “macular pucker.”
Most epiretinal membranes are idiopathic, developing with age as the vitreous gel separates from the retina (a normal process called posterior vitreous detachment). They are usually slowly progressive and affect one eye, though both can be involved. ERM is closely related to other macular interface problems such as macular hole and vitreomacular traction.
Symptoms of epiretinal membrane
Symptoms depend on how much the membrane is distorting the macula. Many people have none, but when present they typically include:
- Distorted central vision — straight lines such as door frames or text look wavy or bent (metamorphopsia)
- Blurred central vision that makes reading and fine detail harder
- Objects appearing a different size in the affected eye (larger or smaller)
- A grey or hazy patch in the centre of vision
- Difficulty with tasks needing sharp focus
Side (peripheral) vision is not affected, and an epiretinal membrane does not cause total blindness.
Noticing wavy lines or blurred reading vision? A vitreoretinal assessment with OCT imaging shows exactly how the membrane is affecting your macula.
Book a retinal assessmentCauses & risk factors
Most epiretinal membranes form for no identifiable reason as part of ageing, but several factors increase the risk:
- Age over 50 — ERM becomes more common with age
- Posterior vitreous detachment — the age-related separation of the vitreous gel from the retina
- Previous retinal tear or detachment, or surgery to repair one
- Retinal vascular disease — such as diabetic retinopathy or vein occlusion
- Inflammation inside the eye (uveitis) or previous eye trauma
How epiretinal membrane is diagnosed
Diagnosis is quick, painless and centred on detailed retinal imaging at a consultant appointment:
- OCT (optical coherence tomography) — the key test; a cross-sectional scan that shows the membrane, the wrinkling it causes and the thickness of the macula.
- Dilated fundus examination — the consultant views the membrane directly on the retinal surface.
- Visual acuity testing — measures how much the membrane is affecting your sight.
- Amsler grid test — a simple chart that maps the distortion in your central vision.
- OCT angiography — used where an underlying vascular cause is suspected.
Treatment options
Not every membrane needs treatment; the decision depends on your symptoms and the OCT findings — see our epiretinal membrane treatment overview for full detail.
- Monitoring — mild membranes that cause little or no distortion are simply watched with periodic OCT scans.
- Vitrectomy with membrane peel — the definitive treatment; a keyhole vitreoretinal operation in which the vitreous gel is removed and the membrane is gently peeled off the macula, allowing the retina to flatten.
- Internal limiting membrane (ILM) peel — often performed at the same time to reduce the small chance of the membrane recurring.
Vision usually improves gradually over the months following surgery as the retina settles, and distortion typically reduces.