An epiretinal membrane (ERM), also known as macular pucker, is caused by an overproduction of protein which accumulates on the surface of the macula. An epiretinal membrane (ERM) occurs in normal eyes.
On a microscopic level, the ERM causes the underlying retina to wrinkle or “pucker,” hence the condition is also known as “macular pucker.”
In my experience, something instigates the extraprotein production. When I examine patients with an ERM, I specifically note the presence or absence of a posterior vitreous detachment (PVD). There is usually a PVD present in most patients with an epiretinal membrane.
Other “causes” include a previous retinal tear, retinal detachment or a history of intraocular surgery, such as cataract surgery.
An epiretinal membrane can cause decreased vision and/or distortion. Remember that the ERM causes the underlying macula to wrinkle. This directly causes decreased vision and/or distortion.
Not all epiretinal membranes need surgery as either patients are asymptomatic (not aware of any vision loss) and the membrane is not progressing.
Surgery to remove the ERM should occur when you are aware of the blurry vision caused by the macular pucker. I recommend operating as early as possible due to the fact that usually there is not complete restoration of vision – there may always be some residual blurring or distortion.
Operating early should maximize your visual prognosis.
Unlike cataract surgery, the timing or indications for vitrectomy to remove the ERM are varied.
Many retina specialists consider the visual acuity as the sole indication for surgery, but this ignores the “distortion” caused by the epiretinal membrane.
Distortion is not measurable and we must rely on your perception of this symptom.