Epimacular Membranes

An epimacular membrane is a thin layer of tissue on the front surface of the macula which is the center of the retina and the region responsible for acute vision.

Q: What is an epimacular membrane (EMM)?

A: A thin layer of tissue on the surface of the macula. The macula is the center of the retina and is responsible for straight ahead vision, fine and color perception.

Q: What are the symptoms of EMM and can it cause total blindness?

A: Although some patients may not have any symptoms, decreased and distortion of central vision are the most common complaints. Epimacular membranes do not cause total blindness.

Q: What causes epimacular membranes and how common is it?

A: A quite common condition, most EMMs develop due to separation of the vitreous (the jelly-like filling of the eye) from the macula. Vitreous separation known as posterior vitreous detachment or PVD is common and is usually due to natural aging changes. In rare cases, prior retinal freezing (cryo) or laser procedures, retinal detachment surgery, or inflammatory and vascular diseases of the eye may be the contributing factors.  

Epimacular membranes are not caused by inheritance or general health problems and there are no life style changes that can reduce their incidence.

Q: How progressive are epimacular membranes and how often are both eyes  involved?

A:  Some people believe that epimacular membranes progress over many months or even years and patients have a gradual decrease in vision over this time. However, epimacular membranes typically develop over a course of four to six weeks and most remain relatively stable thereafter. Most patients develop the condition in one eye only.

Q: How are epimacular membranes diagnosed?

A: Examination of the retina. Ancillary test, especially optical coherence tomography (OCT) are essential tools in aiding the doctor to make diagnostic and treatment decisions.

Q: What is the treatment for epimacular membranes?

A: The only effective treatment is vitrectomy surgery and peeling of the membrane and ILM (internal limiting membrane).

Q: How successful is the surgery and are there any risks involved?

A: When proper technique is used, surgery for this condition has better than a 95% success rate resulting in improved visual function. One of the most important factors of the success is the duration of the condition. Therefore, decision to move forward with surgery must be done in a timely fashion.

As with any procedure, there are setbacks and risks involved. The most common setback is the possibility of rapid progression of pre-existing cataract for which the patient has to undergo cataract surgery. There is a small chance of recurrence of the membrane (less than 1%).