Keeping an eye on epiretinal membranes

Our eyes are delicate, complex organs with many components that work together to enable sight, but they are vulnerable to many conditions and can deteriorate with age. Epiretinal membrane is one such condition that affects the vision. Distinguished consultant ophthalmic surgeon Mr Stephen Lash explains in further depth about this condition and how it can be treated.

Also known as macular pucker, an epiretinal membrane is a scar-like tissue that grows on the macula, which lies in the centre of the retina by the optic nerve. It can be caused by a variety of things such as:

• ageing, as the eyes naturally degrade over time (most common for people over 50 years old) 
• prior eye conditions, like retinal detachment or complications from diabetes
• trauma from previous injuries or surgery

In most cases it is not known why the membrane develops, although it is likely the result of natural separation of the jelly of the eye from the retina. As the gel separates, it may cause tiny abrasions  which stimulate a healing (scarring) response.

What are the symptoms of an epiretinal membrane?

The retina converts light that we see into electrical signals that are passed onto the brain to create images. As the epiretinal membrane shifts, it distorts the retinal tissue and thus vision. Patients may see wavy lines in place of straight lines, and reading becomes especially difficult due to the inability to recognise characters and letters correctly. The perceptions of depth, size, and shape are also affected. The epiretinal membrane tends to only form on one eye, but vision as a whole will be worsened due to the signals from both eyes competing with each other.

How are epiretinal membranes diagnosed?

An ophthalmologist can diagnose an epiretinal membrane with exams and tests. One such method would be to dilate the eye so that the pupil expands, allowing inspection of the retina. There is also optical coherence tomography (OCT), an imaging test that provides a cross-section of the retina in order to confirm there is an epiretinal membrane.

How is an epiretinal membrane treated?

Most patients may not experience extreme distortion to vision and the growth will halt after a while, but those who are undergoing significant visual deterioration will require surgical treatment, as there are no medications that are available to treat or disrupt the growth of the epiretinal membrane. The surgery, called a vitrectomy, involves the removal of the vitreous gel (the jelly-like fluid inside the eye) to allow access for the surgeon to excise the epiretinal membrane. This is a short surgery and is performed under a local anaesthetic. The improvement is not immediate but will gradually become apparent over a few weeks, with patients reporting a 70 per cent improvement in vision. Patients of the vitrectomy have a high likelihood of developing cataracts, so sometimes this procedure is done in conjunction with cataract surgery.

Surgery will take around 20 minutes to half an hour and may require cataradct surgery at the same time as cataract tends to develop quickly after this surgery. The main aim of surgery is to stop the vision from getting worse, but there is an average gain of one to two lines down the eye test chart and notable significant reduction in distortion.

If you are experiencing issues with your vision, ophthalmologic surgeon Mr Stephen Lash is available for consultation via his Top Doctors profile.