Epiretinal membrane

What is an epiretinal membrane?

epiretinal membrane

This is a colour picture of an epiretinal membrane. There is a shine across the retina and the blood vessels become distorted. Epiretinal membranes cause change in magnification (metamorphopsia)
and distortion of vision.

The retina is a thin layer of light sensitive cells lie at the back of the eye. It is attached to a gel in the eye – called the vitreous. With age the vitreous may detach from the back of the eye. As it does, cells are released into the vitreous cavity. These cells lie on the retinal and form collagen, which looks like a thin layer of cling film plastic. This then contracts across the retina forming the epiretinal membrane. The retina then thickens, distorts and vision become blurred.

What are the symptoms of an epiretinal membrane?

An epiretinal membrane will cause distorted and blurred vision. Straight lines will appear bent or crooked, and reading can become difficult.

Will I need any special tests?

You will commonly need to have an optical coherence tomography (OCT) examination, and in some cases a fluorescein angiogram will be needed.

An OCT of an epiretinal membrane shows a the thickened layer on top of the retina.

OCT of an epiretinal membrane

An OCT of an epiretinal membrane – this shows the retina with an extra layer of scar tissue lying over the surface. This constricts and elevates the retina, as the retina is elevated the vision becomes blurred.

How is an epiretinal membrane treated?

It is treated with an operation called a vitrectomy-peel. The eye is anaesthetised with a local anaesthetic. Three small incisions are made and the gel in the eye is removed. Following this a dye is used to stain the epiretinal membrane and which is then peeled from the back of the eye using micro-forceps.

What happens during treatment?

The treatment can take place in the day case theatre. First the pupil is dilated with drops, this takes about 20 minutes. Then an anaesthetic will be infused around the eye. The actual operation then takes 30-40 minutes.

Are there any risks of treatment?

The development of a cataract is the most important risk, with most patients needing cataract surgery within 12 months. Fortunately these are usually successful and can further improve vision. Some patients develop a retinal detachment, which can reduce vision dramatically. If detected early these can also be operated on and vision restored. Other risks include infection of the eye, and a recurrence of the epiretinal membrane.

What happens after treatment?

Immediately after the operation, your eye should be padded and kept comfortable. The eye should be examined the following day and post operative drops prescribed. A patient will probably not see well from the eye for at least one month. Over time the vision can improve dramatically in around 70% of patients. In some patients the surgery can be successful, however the vision may not improve. For most people having retinal surgery cataracts develop in the next few months and these may need surgery.

Long term you may find your glasses prescription changing and often a cataract develops following surgery. This can be removed with cataract surgery.

Is an Epi-retinal membrane the same as macular degeneration?

No, epi-retinal membrane and macular degeneration are two separate and distinct conditions. Macular degeneration is a condition affecting the tissues lying under the retina, while a macular hole involves damage from within the eye.

How long can epiretinal membrane surgery wait?

Epiretinal membrane surgery is effective as long as you have symptoms and clear thickening of the membrane on OCT.