An epiretinal membrane (ERM) is generally not regarded as an urgent problem and is highly unlikely to cause blindness. The ERM is a sheet of fibrotic tissue which grows on the surface of the retina (between the retina and vitreous). This contracts and causes physical distortion of the retina and impaired vison.
ERM occurs most commonly at the macula and as a result causes problems with the central detailed vision. ERM can be removed with vitreoretinal surgery; however, many ERMs are only mild and do not require surgical intervention.
The outcome of ERM removal can be unpredictable in terms of whether a visual improvement will be noticed. Surgeons tend to wait until symptoms are significant before attempting ERM removal. During the surgery the vitreous is removed from the eye and then the ERM is peeled off the retina using very delicate instruments. Visualisation of the ERM is sometimes enhanced with the use of a special dye which stains the ERM allowing easier and safer peeling.