Epiretinal Membrane

An epiretinal membrane (ERM), also called a macular pucker or cellophane maculopathy, is a thin layer of fibrous scar tissue that forms on the surface of the macula. It can contract and wrinkle the retina underneath, causing distorted or blurred central vision. Many ERMs are mild and require no treatment, but significant cases may benefit from surgical removal.

Overview

Epiretinal membranes are one of the most common macular conditions. They develop when cells migrate onto the macular surface and form a thin, transparent-to-translucent membrane. In mild cases, the membrane sits quietly on the surface without affecting vision. In more significant cases, the membrane contracts, wrinkling the underlying retina and distorting vision.

Symptoms

Mild ERM (Often Asymptomatic)

Many people with an ERM have no symptoms at all and the membrane is found incidentally during a routine eye exam.

Significant ERM

• Distorted vision (metamorphopsia) — straight lines appear wavy or bent
• Blurred central vision
• Difficulty reading fine print
• Double vision in one eye (monocular diplopia)
• Objects may appear larger (macropsia) or smaller (micropsia) than they are
• Decreased contrast

Causes and Risk Factors

How ERMs Form

Most epiretinal membranes are idiopathic (no specific cause), developing from:

1. Posterior vitreous detachment (PVD) — as the vitreous gel separates from the retina, it can leave behind cells or trigger cell migration onto the macular surface
2. These cells proliferate and form a membrane
3. The membrane may contract, pulling on and wrinkling the retina

Secondary Causes

ERMs can also develop after:

• Retinal tears or detachment (and their repair)
• Eye surgery (cataract surgery, retinal surgery)
• Eye inflammation (uveitis)
• Retinal vascular diseases (diabetic retinopathy, retinal vein occlusion)
• Eye trauma

Risk Factors

• Age over 50 — prevalence increases with age
• Previous PVD
• History of eye surgery or retinal disease
• Diabetes

Diagnosis

• Optical coherence tomography (OCT) — the essential test; shows the membrane on the macular surface, any retinal wrinkling or thickening, and helps track changes over time
• Amsler grid — documents distortion
• Visual acuity testing — may be mildly reduced or normal
• Dilated fundus exam — membrane may be visible as a glistening, cellophane-like sheen on the macula

Treatment

Observation (Most Cases)

The majority of epiretinal membranes are mild and stable:

• Regular monitoring with OCT every 6-12 months
• No treatment needed if vision is good and stable
• Many ERMs remain stable for years without significant progression

Surgery: Vitrectomy with Membrane Peel

Indicated when the ERM significantly affects vision or quality of life:

• Vitrectomy — removal of the vitreous gel
• Membrane peeling — the surgeon carefully peels the membrane from the retinal surface using micro-forceps
• ILM peeling — the internal limiting membrane may also be removed to reduce recurrence risk
• Outpatient procedure under local anesthesia
• No gas bubble or face-down positioning required in most cases (unlike macular hole surgery)

Success rate:

• Vision improves in about 80-90% of cases
• Distortion typically improves significantly
• Improvement is gradual, often continuing for 3-6 months or longer

When to Consider Surgery

• Vision impaired enough to affect daily activities (reading, driving)
• Significant distortion that bothers you
• Progressive worsening on OCT despite observation
• Generally, earlier surgery (before the macula is severely thickened) yields better outcomes

When to See a Doctor

Frequently Asked Questions

Will my epiretinal membrane get worse?

Many ERMs remain stable for years and never require treatment. Some do slowly progress. Regular OCT monitoring helps detect changes early so surgery can be planned if needed.

Can an epiretinal membrane go away on its own?

Rarely, an ERM can spontaneously separate from the retina, particularly after a posterior vitreous detachment. However, this is uncommon, and most persistent membranes that affect vision will require surgery if improvement is desired.

How long does recovery from membrane peel surgery take?

Most people return to normal activities within 1-2 weeks. Vision improvement is gradual, with most improvement occurring over 3-6 months. Some patients continue to notice improvement for up to a year.

Will the membrane come back after surgery?

Recurrence is uncommon, occurring in about 5-10% of cases. Peeling the internal limiting membrane (ILM) along with the epiretinal membrane further reduces recurrence risk.

Is epiretinal membrane the same as macular degeneration?

No. An epiretinal membrane is a membrane growing on top of the macula, while macular degeneration is degeneration of the retinal tissue itself. They are different conditions with different treatments.

References