Epimacular membranes, also called epiretinal membranes, are unusual membranes that form on the surface of your retina. These membranes can contract, and when they do, they distort your retina, and therefore your vision. Here are three things you need to know about epimacular membranes.
Why do these membranes form?
Epimacular membranes contain a variety of different cell types. They contain the following cells:
Glial cells, which help to support your nervous system;
Retinal pigment epithelial cells, which absorb light that hits your retina;
Macrophages, which are a kind of white blood cell;
Fibrocytes, cells that produce collagen;
Collagen, the most abundant protein in your body.
As you can see, this is an unusual grouping of cells, and researchers have debated why they come together to form epimacular membranes. It's suspected that epimacular membranes form in response to a posterior vitreous detachment (PVD). PVD means that your vitreous (gel-like eye filling) pulls away from your retina. When this happens, the cells that are normally present in your retina get displaced, while the associated inflammation draws additional cells to the scene.
PVD is a common eye condition that will happen to most people at some point. As you age, your vitreous changes consistency and moves away from the retina. For most people, PVD isn't a problem, but in some cases, an epimacular membrane can form in response.
What are the signs of epimacular membranes?
Epimacular membranes can lead to vision loss or changes in your vision. You may notice vision decay, which means that your vision is decreasing over time. You may also notice a type of vision distortion called metamorphopsia. Metamorphopsia means that when you look at a straight line, you see a wavy line. This distortion is most obvious when you're looking at something that you know should be a straight line, like the grid of your crossword puzzle.
How are epimacular membranes treated?
Epimacular membranes are treated surgically. First, you'll undergo a vitrectomy. Your surgeon will remove the vitreous from the inside of your eye; this is done so that they can get access to your retina. Once the vitreous has been removed, the next part of your surgery can begin: epiretinal membrane peeling.
Your surgeon, with the help of a microscope, will use a pair of very tiny tweezers to peel the membrane off of your retina. Once the membrane has been removed, your eye will be re-filled with saline. This saline replaces the vitreous that was removed.
This surgery is very effective and between 80% and 90% of patients see an improvement in their vision in the months following the procedure. In about 10% of cases, the membrane will grow back and require further treatment.
If you think you have an epimacular membrane, see your optometrist (like those at Village Eye Centre) immediately.