An epiretinal membrane is a proliferation of abnormal tissue on the surface of the retina. The abnormal tissue tends to accumulate in the center of the retina in an area called the macula. The macula contains the highest concentration of cells responsible for the reception of light stimuli from our environment. It is the macula that is responsible for the central portion of our vision. Common synonyms for epiretinal membrane include macular pucker, premacular fibrosis, cellophane maculopathy, surface wrinkling retinopathy and epimacular membrane.
The majority of patients who get epiretinal membranes are over the age of 50 years old. Occasionally, children and young adults may get an epiretinal membrane. The prevalence of epiretinal membrane in patients over the age of 50 is probably about 6%.
There are several causes of epiretinal membrane. They may occur after intraocular surgery, particularly after retinal detachment. Any type of intraocular inflammation can cause epiretinal membrane. Holes or tears in the retina and ocular trauma or injury can incite membrane formation. Some membranes are idiopathic meaning that there is no obvious cause.
The most common symptom of epiretinal membrane is visual distortion. Objects may look irregular or bent. As the membrane progresses, the retina becomes thickened. This is referred to as retinal or macular edema. A special test called optical coherence tomography is very accurate at detecting macular edema.
Optical Coherence Tomogram centered under the two images.
The only treatment for epiretinal membrane is surgery. Medications such as nonsteroidal antiinflammatory agents may decrease the macular edema but will not cure the membrane. The majority of membranes remain relatively asymptomatic for long Periods of time. The mere presence of a membrane is not an indication for surgery. When patients are sufficiently bothered by the decrease in vision or the distortion caused by the membrane, a vitrectomy may be indicated.
A vitrectomy is a surgical procedure where the vitreous gel inside the eye is removed and replaced with either a salt solution or gas. The membrane can then be peeled away from the surface of the retina. The majority of patients obtain good vision after this type of surgery. Some of the possible complications of vitrectomy surgery are cataract formation, retinal detachment, and infection.