What Is an Epiretinal Membrane?

Medically Reviewed by Poonam Sachdev on August 22, 2022
5 min read

An epiretinal membrane (ERM) is an eye condition where a layer of cells forms on the inside of your retina. This layer of cells is called a membrane. Many people with this condition don’t know that they have it until it’s diagnosed during an eye exam.  

Epiretinal membranes are known by a handful of different names. These include: 

  • An epimacular membrane
  • Surface-wrinkling retinopathy
  • Cellophane maculopathy
  • Preretinal macular fibrosis

Your retina is a nerve layer at the back of your eye. When it senses light, it sends nerve impulses to your brain. This means that your retina is a key part of your visual system. An epiretinal membrane forms on the inner surface of your retina

The macula is the central portion of your retina. It allows you to:

  • Distinguish fine details
  • Recognize faces
  • Read faces 

Severe epiretinal membranes can cause your macula to pucker. This can greatly affect your vision. 

Epiretinal membranes are specifically made up of glial cells. These cells are associated with your nerves but aren’t functional nerve cells. Instead, they serve a supportive role within your nervous system. They’re typically associated with the nerves in your retina, but they aren’t supposed to form a membrane across the retina. 

Epiretinal membranes form in both males and females. They’re equally common in people of all sexes. 

About 10 to 20 percent of people with an epiretinal membrane in one eye also form one in their second eye. 

Risk factors that are associated with epiretinal membranes include: 

Age is one of the biggest factors that affect the development of epiretinal membranes. The average age of detection is 65 years old. About two percent of people over the age of 50 develop these membranes. This increases to 20 percent for people over the age of 75. 

In many cases, the cause of your epiretinal membrane is unknown. This condition is called an idiopathic ERM. 

Less frequently, epiretinal membranes are associated with other retinal problems. These conditions can include: 

In many cases, some kind of defect or tear in the surface of your retina allows glial cells to migrate to places they don’t belong. They start growing and form a sheet across the surface of your retina. This is the epiretinal membrane. 

Most of the time, people don’t know that they have an epiretinal membrane until it’s observed during a standard eye exam. 

Your eye doctor will base their diagnosis on your medical history and the results of a clinical exam. Sometimes, a technique called optical coherence tomography (OCT) can help with the diagnosis and determine how severe the condition is. 

OCT is a way to take high-resolution images of your eye. These images can be viewed as cross sections or as a three-dimensional representation of your eye. 

The membrane can take on different appearances and configurations as it forms. These differences can lead to dramatically different symptoms. Luckily, many people don’t experience any symptoms at all. 

In other cases, the membrane can begin to look like cellophane or could tighten. This tightening can pull on your retina and cause visual distortion. These visual problems can gradually get worse. 

The most common distortion is metamorphopsia. This occurs when objects that should look straight take on curved or wavy appearances. This is sometimes easier to notice when you cover your healthiest eye and only look through the eye that’s most affected. 

Other symptoms include: 

If your epiretinal membrane isn’t causing any visual complications, then you don’t need immediate treatment. On the other hand, if you’re experiencing visual problems, then the best treatment is epiretinal membrane surgery. The formal name for this surgery is a vitrectomy. 

Eye doctors tend to recommend surgery if your vision problems are interfering with your daily life or if your vision is significantly worse than 20/50. A measure of 20/20 represents ideal vision.  

Surgery essentially involves opening up your eye and removing the membrane with any number of tools, including: 

  • Forceps
  • A pick
  • Diamond-dusted instruments 

The surgery does have potential complications, unfortunately. For example, one in 100 people develops a problem called retinal detachment. One in 2000 people will get an infection after surgery. 

Your eye doctor will want to regularly monitor your condition if you have epiretinal membranes but don’t have any symptoms. This way, they can develop a treatment plan as soon as the membranes start causing problems. 

Your eye doctor should also regularly check on your other eye once they’ve detected an epiretinal membrane in the first eye. Although there’s nothing you can do to prevent your first epiretinal membrane, you might be able to keep one from forming in your second eye. Specifically, you can keep another membrane from forming by treating any underlying conditions that led to the first one. 

Many people who undergo surgery to remove their epiretinal membrane see improvements within the first three to six months. Others don’t see improvements until one or two years after the surgery. The time it takes for your eyes to recover depends on a number of factors, including: 

  • How long you have had the membrane before your operation
  • How much the membrane was pulling on your retina
  • The cause of the membrane — people with idiopathic epiretinal membranes have a better chance for a complete recovery 

There’s a one percent chance that your epiretinal membrane will come back after surgery. 

You should see an eye doctor whenever you first notice problems with your vision, including visual distortions like metamorphopsia. The sooner that you talk to a medical professional, the sooner you can get treatment. It’s also important to have regular eye exams so your eye doctor can detect problems as soon as possible.