Epiretinal Membrane

 What is an epiretinal membrane?



Some patients develop a thin layer of scar tissue on the surface of the centre of the retina (photographic film at the back of the eye) called an epiretinal membrane (sometimes also called cellophane maculopathy). This thin layer of scar tissue does two things, it impairs the light getting to the retina (causing blurring of central vision) and it contracts (causing wrinkling of the underlying retina with distortion of vision).

This scar tissue formation is often associated with a degenerative change within the jelly that occupies the main eye cavity. The jelly is called vitreous and with the passage of time turns from being jelly like to a more watery consistency. This watery consistency allows cells (including scar tissue cells) to move around more freely inside the eye and the scar tissue cells like to settle on the central part of the retina (macula) where they form a sheet of tissue attached to the retina which then contracts to cause the retina to wrinkle.  The treatment for this condition is a surgical procedure called a vitrectomy and membrane peel.

What is the surgical treatment of epiretinal membrane?



Scar tissue can form on the surface of the retina and in particular likes to form at the centre of the retina or macula. This results in a gradual blurring of vision and is often accompanied by distortion of vision as the scar tissue contracts and wrinkles the underlying retina.

The scar tissue can be removed with an operation often termed a “vitrectomy and membrane peel”. In order to gain access to the scar tissue on the surface of the retina the jelly that occupies the main eye cavity (vitreous) has to be removed. The surgery can be under general or local anaesthetic as a day case procedure. It involves creating three very small incisions in the sclera (white of the eye) at the front of the eye and all instruments are placed through these small incisions.

The jelly is first removed and then a fine pair of forceps is introduced into the vitreous cavity to pull away the scar tissue. In most patients the tissue comes away with ease but sometimes the scar tissue can be “stuck” to the retina and comes away in a piecemeal fashion. This type of surgery on the retina is therefore by its nature not as predictable as cataract surgery where up to 99% of patients will get an excellent result. Most patients having surgery for epiretinal membrane will notice an improvement in their vision and a reduction in the amount of distortion. There may however still be some mild visual disturbance even after technically successful surgery. Things can however continue to improve many months after surgery although most of the improvement tends to occur within the first 3 months.

The vitrectomy operation if performed alone will eventually result in the development of a cataract. I therefore routinely perform what is called “combined surgery” for patients with epiretinal membranes. This involves removing the lens of the eye at the time of the vitrectomy surgery and replacing it with a new plastic intraocular lens. This is identical to the cataract surgery which occurs when the lens is cloudy. The advantage of this “combined” approach is that it prevents you having to come back for further cataract surgery months or years after the vitrectomy operation.