Scar tissue can grow on the surface of the retina, directly over
the macula. This scar tissue can contract, and cause the retina
to wrinkle. The scar tissue on the surface of the retina is
called an "epiretinal membrane" or "macular pucker". An
epiretinal membrane can cause visual loss, as well as distorted
or double vision.
Epiretinal membranes may be caused by a variety of eye problems.
They may follow retinal detachment surgery or laser treatment or
cryotherapy for retinal tears. They may be associated with
retinal blood vessel problems. In most cases, the epiretinal
membrane occurs in an otherwise healthy eye as a result of a
posterior vitreous detachment.
The only treatment for visual loss caused by an epiretinal
membrane is surgery to remove the membrane. If the vision is
only mildly reduced, it is best not to do surgery. If the visual
loss or distortion is significant, however, a vitrectomy may be
performed to remove the membrane. This surgery is usually
performed under general anesthesia. The membrane is picked up
with a fine instrument and gently peeled off the surface of the
Vision usually improves slowly after surgery, with most of the
improvement coming within the first three months, though it may
continue to improve for many months. In some cases, the vision
may not improve at all. The chance that vision will improve
following surgery is about 75%. On an average, patients regain
approximately half of the vision that was lost because of the
The complications of the surgery include retinal tears and
detachment, cataract formation, infection, and regrowth of the
membrane. These complications may result in mild to total loss
of vision, though vision-losing complications are rare.