There are a lot of different conditions that affect the eyes and one of the more interesting is called epiretinal membrane (ERM). An ERM is also sometimes called a macular pucker, premacular fibrosis, surface wrinkling retinopathy or cellophane maculopathy. An ERM is a thin sheet of fibrous tissue that can develop on the surface of the area of the retina called the macula. The macula is responsible for fine vision that you use to read and recognize objects.
ERMs can cause a disturbance in vision often described as:
- metamorphopsia (distorted/wavy vision)
- blurred vision,
- monocular double vision, and
- micropsia (objects are seen as smaller than they actually are)
- most patients with ERMs are asymptomatic.
Don’t worry… an ERM will not cause total blindness – it will typically only affect the central vision in the affected eye, while the peripheral vision remains unaffected. Sometimes, the ERM can be very mild and has no effect on vision at all. In other cases, the ERM may worsen over time, causing blurring and distortion to the central part of your vision.
ERMs may contract like scar tissue, which can pull on the delicate retina at the back of your eye. This ‘puckering’ of the macula can distort your vision, and can also cause the retina to swell so it doesn’t work as well. In most cases, ERMs occur in people with no history of eye problems. It is usually caused by natural changes in the vitreous gel inside the eye. These changes cause cells from the retina and other parts of the eye to be released into the vitreous gel, and they eventually settle on the macula, where they can form a membrane. Secondary ERMs occur in association with retinal vascular diseases, ocular inflammatory disease, trauma, intraocular surgery, intraocular tumors, and retinal tear or detachment. Other risk factors include age, posterior vitreous detachment, and history of ERM in the fellow eye. The mean age of ERM diagnosis is 65 years old.
The OCT device has become increasingly helpful in the diagnosis and management of this disorder. This high-resolution image can allow evaluation of the macula in cross section and three-dimensionally. OCT can be helpful detecting subtle ERMs as well as when associated with macular swelling or other macular pathology. OCT can also help guide management. In surgical cases, evaluation of the OCT scan can help with the best approach for removal.
Epiretinal membrane surgery is the most common vitreoretinal surgery performed. Surgery involves removing the vitreous gel and replacing with with saline and peeling the membrane away from the retina. Visual acuity improvement does not occur immediately in some patients. This is highly dependant on preoperative characteristics, duration of the ERM, as well as other factors. Most patients improve by 3-6 months postoperatively. However, some may experience improvement 1-2 years postoperatively.