What is an epiretinal membrane?
Epiretinal membrane (ERM) refers to a thin, semi-opaque layer of fibrous tissue that forms over the macula, an important part of the retina that is responsible for processing sharp details and colors.
This eye condition, also known as cellophane maculopathy or macular pucker, is different from macular degeneration and macular holes. When an ERM develops, a cellophane-like scar tissue forms over the macula, which may cause vision to become distorted or blurry. Most people who develop an ERM do not have symptoms and do not need treatment. Their vision can be monitored at routine eye exams to watch for progression.
An ERM can shrink and pull on the macula, causing the macula to wrinkle or pucker, which is why an ERM is also known as macular puckering. Macular puckering can cause central vision to be distorted (metamorphopsia). That is, straight lines may look wavy, flat objects may appear round, and shapes may seem smaller than normal (micropsia) or larger than normal (macropsia).
Daily activities, such as driving, reading and identifying small details, may be affected due to this lack of visual clarity. At this point, epiretinal membrane surgery (vitrectomy) is recommended to stop the progression of the condition. This procedure also includes an epiretinal membrane peel (membranectomy).
Macular pucker, also known as epiretinal membrane, is a thin, film-like tissue that can form over the macula and cause distorted, blurry vision. [Image credit: Macular pucker. Permission granted by © 2022 American Academy of Ophthalmology]
What causes an epiretinal membrane?
According to the National Institutes of Health, the exact cause of an epiretinal membrane is unknown, and you can develop an ERM even if you don't have any history of eye problems or any of the risk factors listed below.
Underlying factors that may contribute to ERMs include:
Posterior vitreous detachment, a very common condition associated with ERMs
Aging, especially age 50 and older
Previous eye surgeries, including procedures for cataracts or retinal detachments or tears
Head or eye injury or trauma
Inflammation inside the eye (uveitis)
Diabetes or diabetic retinopathy
An existing ERM in the other eye
Signs and symptoms of an epiretinal membrane
The majority of people with an ERM show no signs or symptoms, so having an annual eye exam is important for early detection and monitoring as ERMs slowly get worse over time.
If symptoms of an epiretinal membrane are present, they may include:
Distortion – A straight line appears crooked or bent.
Difficulty reading – The letters of reading material seem unusually small or large.
Blurry vision – The features of a person's face aren't sharp or easily distinguishable.
Double vision (diplopia) – A single object looks like two objects.
Decrease in visual acuity – Less visual sharpness than in the past.
It’s important to visit an eye doctor if you notice any signs and symptoms associated with an ERM — or if symptoms persist, worsen or change.
An epiretinal membrane can happen to anyone but it is more commonly found in the older population, specifically 2% in those over age 50 and 20% over age 75. Most of the time, an ERM presents in one only eye, but in about 10% to 20% of cases, it can occur in both eyes. However, having an ERM in one eye can increase the likelihood of getting it in your other eye.
