An Epiretinal Membrane (ERM) or macular pucker is caused by a fibrous membrane that grows over the macular surface. In some individuals, this membrane contracts, which resultis in wrinkling of the retina. This contraction may mechanically irritate the retina and cause retinal swelling. Approximately 20% of epiretinal membranes progressively worsen.
An ERM may cause symptoms ranging from minor distortion of images, to severe loss of vision. Visual acuity can range from 20/20 to 20/200.
An Epiretinal Membrane has a characteristic clinical appearance, and the diagnosis is made by the physician during a dilated exam. Optical Coherence Tomography (OCT) which provides a scan, or slice of the retina can be very useful in identifying epiretinal membranes. In some cases Fluorescein Angiography may be used to rule out other retinal diseases.
When vision declines, vitrectomy surgery to remove the epiretinal membrane may be recommended. Eye drops, medications or glasses will not correct the loss of vision. During vitrectomy surgery, the vitreous gel is removed. Following this, the epiretinal membrane is peeled from the surface of the retina and removed using microscopic forceps. Removing the vitreous is not harmful to the function of the eye. Vitrectomy surgery is an outpatient procedure usually performed under local anesthesia. Significant improvement in vision occurs in most patients after epiretinal membrane removal.