If the eye is like a camera, then the retina at the back of the eye is the photographic film. The retina is a very thin layer of tissue that captures light rays and converts them into electric impulses via the optic nerve to the brain – like a messenger that sends information, which is then interpreted by the brain into visual images.
At the very centre of the retina is something called the macula. This is an important, sensitive area of the retina providing the detailed vision we need for reading and for recognising shapes.
When people are aged over 50, it is possible for a thin sheet of scar-like tissue to form over the macula – this is what is known as epiretinal membrane, ERM for short, or macular pucker, as it is also known.
When this membrane becomes thicker, the retina wrinkles and vision will become twisted or distorted. For some, letters, numbers and straight lines will appear distorted, or look jumbled on a page they are reading. Despite this, epiretinal membrane doesn’t cause total blindness, but it does typically affect the central vision. Peripheral (side) vision is usually unaffected.
Most of the eye’s interior is filled with a gel-like substance, called the vitreous, which enables the eye to maintain its round shape. Within the vitreous, there are millions of ultra-fine fibres that are attached to the retina.
When we age, the vitreous begins to shrink. This can cause it to slowly pull away from the retinal surface, pulling with it the fibres attached to the retina. This can lead to a vitreous detachment or retinal detachment. Generally, there are virtually no obvious effects apart from an increase in “floaters” – the tiny specks or “cobwebs” that appear to float within the field of vision.
However, when the vitreous completely pulls away from the retina, a healing process will naturally occur within the damaged area, causing scar tissue to form on the surface of the retina. When the scar tissue stops growing and begins to shrink, the retina will begin to wrinkle, or pucker. This may not always affect vision.
The problems are generally caused when this scar tissue forms over the macula in the centre of the retina. This results in blurred and distorted central vision. While much less frequent, the same issue can also be caused by an eye operation, or inflammation.
So, it’s important to understand that many people with epiretinal membrane are not seriously affected in their daily life. If vision is still acceptable, there is no need to take action and no further treatment is required beyond making sure that the condition is monitored regularly.
When an epiretinal membrane affects the vision, this will require management and treatment.
The most noticeable signs are when fine details become difficult to discern, particularly when reading. At first, there might be a slight distortion of vision, difficulty seeing small print and straight lines may look wavy. It’s also possible to become aware of a small blind spot or grey area in the centre of vision. Using an amsler grid regularly to check your vision can disclose signs of an epiretinal membrane – click here to download your free amsler grid.
When these symptoms are apparent it’s vital to not delay seeking treatment. Epiretinal membrane is a progressive condition and will generally worsen over time, so early surgery will help ensure the best results. Visit one of our clinics today!
Once the condition is confirmed as progressive by an ophthalmologist – the only option is to to proceed with a vitrectomy.
The good news is that a vitrectomy is typically highly successful. In fact, over 80% of patients find that their overall quality of vision improved, and 70-80% can see better centrally. The longer the epiretinal membrane has been present, the less improvement in vision there is likely to be.
New techniques and instrumentation allow for faster healing, with minimal post-operative irritation. An eye patch is required for 24 hours or so, followed by eye drops or ointment to assist healing.
Overall, patients can resume their normal, everyday routine very quickly. Most patients can resume non-strenuous activities after a day, but the time required to work, play sports or drive can vary from person to person. Therefore, a patient shouldn’t try to rush the recovery process if they don’t feel ready.
The treatment for epiretinal membrane is very effective, but only if it is carried out before the damage becomes too great. The symptoms can be deceptive and the condition may appear to stabilise, but will actually become progressively worse. While it’s not a medical emergency, it’s still important to be diagnosed and arrange for treatment as soon as possible.