An epiretinal membrane (ERM), or macular pucker, is a thin layer of tissue that grows on the surface of the macula. It is found in normal, healthy eyes and may cause decreased vision and/or distortion.
Epiretinal membranes are not related to macular degeneration.
ERM = Macular Pucker = Cellophane Maculopathy = Wrinkle
The most common symptoms of a “macular pucker” include decreased vision and/or distortion. The protein sheet spreads across the macula and gently tugs and displaces the retinal tissue causing these symptoms.
The gentle tugging, on a microscopic level, disrupts the cellular interactions of the rods and cones causing the visual changes. The membrane can cause the retina to “wrinkle” and hence the name “pucker” or “wrinkle.”
Mild “trauma” or previous eye surgery causes the formation of the membrane. In most cases, a PVD (posterior vitreous detachment) has occurred. This mild stimulation excites/irritates special cells on the retina to produce a protein. This protein is overproduced and forms a layer on the surface of the retina.
Not all patients will get an ERM. Only patients with a genetic predisposition for “overproducing the protein” will develop epiretinal membranes.
The only known treatment for macular pucker is vitrectomy surgery. The vitrectomy is the basic surgery of most retinal operations. The vitreous is removed allowing access to the surface of the retina.
Forceps are then used to grasp the edge of the membrane and gently peel the membrane off the surface of the retina.
Warning: this video demonstrating vitrectomy for epiretinal membrane is graphic!
I like to use either ICG dye or Brilliant Blue (another tissue dye) to stain the ERM prior to removal. The stain allows me to see the tissue much easier.
What Does this Mean?
I recommend operating as soon as you are aware of symptoms. The most common symptoms are distortion and decreased vision.
Unlike cataract surgery where the “severity” of the cataract does not correlate with the degree of visual improvement, no one can guarantee how much vision will return after successful ERM surgery… no one.
Therefore, I recommend removal as soon as you notice either slight blurring and/or distortion. Some docs feel that vision must be reduced to a required level before considering surgery (e.g. 20/40 for cataracts), but since we can’t measure distortion, I feel this is not the best approach.
Occasionally, some patients have both cataracts and a macular pucker. I will usually recommend cataract surgery before macular pucker surgery; it will improve my view if I need to operate, the resultant vision after cataract surgery may be sufficient (we might avoid or delay ERM surgery) and cataract surgery prior to ERM surgery may decrease the chance of recurrence.