Color fundus photo of a patient with an epiretinal membrane resulting in subtle wrinkling or retinal striae.
An epiretinal membrane (ERM), also called macular pucker, is a fibrocellular membrane that forms on the inner surface of the retina. It most commonly causes minimal symptoms and can be simply observed.  Generally, it is most symptomatic when affecting the central macula and leading to the formation of wrinkles which can result in metamorphopsia (visual distortion).

What Causes ERMs?

Age is the most common cause of epiretinal membranes. As you get older, the vitreous begins to shrink and pull away from the retina, resulting in development of a posterior vitreous detachment or (PVD). Usually the vitreous pulls away with no problems. But sometimes the vitreous can stick to the retina. Scar tissue forms, causing the retina and macula to wrinkle or bulge.

What are the Risk Factors for ERM?

How is an ERM Diagnosed?

Most ERM cases can be diagnosed clinically during a dilated fundus exam.  The most common imaging modality to visualize epiretinal membranes is Ocular Coherence Tomography (OCT) which is used to assess the severity of the ERM. In addition, another method to further evaluate if other underlying retinal problems have caused the ERM is fluorescein angiography. 

OCT scan showing a cross-sectional view of the macula with a thin ERM on the surface.

How is ERM Treated?

Treatment of ERM depends on your symptoms. If your symptoms are mild, you might not need any treatment. Instead, you may be able to change your glasses or contact lens prescription to improve your vision. You might also choose to wear bifocals when you are looking at something close. Eye drops, medicine, and laser surgery do not help vision if you have an ERM. However, you may be prescribed these treatments if you have other conditions mentioned above. 

If your symptoms are more serious, you may benefit from surgery called vitrectomy and membrane peel. This is where some of the vitreous and scar tissue on your macula is removed to flatten the macula. It is likely your vision will slowly improve. However, your sight may not be as good as it was before the formation of the ERM.

Source: American Academy of Ophthalmology