The retina is the light-sensitive tissue that lines the inside wall of the eye and enables sight. The macula is the central part of the retina that is responsible for seeing straight ahead. A macular pucker is scar tissue that forms on the surface of the macula. Other names for this condition include: epiretinal membrane, pre-retinal membrane, cellophane maculopathy, and surface wrinkling retinopathy.
Macular pucker can cause blurry and distorted central vision. This can be a significant problem because a healthy macula is needed to see the fine detail required for reading and driving. A macular pucker is not related to macular degeneration, these are two different problems. A macular pucker should not be considered a precursor to a macular hole.
Causes and Associations
We know that development of macular pucker is often related to age. They are most common in patients over 50. The most common cause of macular pucker relates to traction from the vitreous, which is a gel-like substance that fills the center of the eye. The vitreous gel is normally clear and is mildly adherent to the retina lining the back of the eye. As we age, the vitreous gradually shrinks and pulls away from the back of the eye wall. This is a normal process and the eye produces natural, clear fluid that fills the areas where the vitreous has contracted. Sometimes patients see floaters when the vitreous begins to pull away from the retina.
Sometimes when the vitreous pulls away from the retina there is microscopic damage to the retinal surface. The retina may respond to this insult by forming scar tissue or an epiretinal membrane on the surface of the retina. When this scar tissue contracts, it causes the retina to wrinkle or pucker, which distorts central vision.
In addition, development of macular pucker can be more likely in patients who have had trauma, retinal tears or detachments, retinal vein occlusion, diabetic retinopathy or inflammation in the eye.
Problems from a macular pucker usually occur gradually. The first symptoms are often blurry and distorted central vision. Straight lines might look wavy, distorted or have missing segments. There may be a gray area in the central vision. Sometimes a patient does not notice a problem for some time because they do not cover their good eye and realize that they have a problem looking with the eye containing the macular pucker. Reading often becomes difficult.
Examination & Testing
It is important to be examined by an ophthalmologist who can often diagnosis a macular pucker by examining the eye.
- Visual Acuity
Testing visual acuity is one way to measure the functional severity of macular pucker. An Amsler grid is similar to a piece of graph paper that patients can use to detect subtle changes in their central vision. Patients look at the grid with each eye individually and report to their doctor if there are any missing areas or the lines look distorted or wavy.
2. Optical Coherence Tomography (OCT)
In addition, the ophthalmologist may obtain a scan using optical coherence tomography (OCT). OCT uses light to produce images of the retina. The resolution of the images is very fine, and doctors can see problems that exist above, below, and within the retina. During an OCT, a patient will sit and place their head in a chin rest while looking into a machine. The patient will see lights moving around. Nothing touches the patient and there is no pain. Doctors can use the OCT images to determine the presence and severity of macular pucker.
What the Doctor Sees
When a doctor examines the patient, he or she will use a slit lamp thatprojects a bright light into the eye and use a lens to focus the light on the macula. Usually the doctor can see the macular pucker. The doctor may note swelling of the retina that can result from macular pucker.
For most people, visual problems from macular pucker progress slowly and vision can remain stable for a long time. Most instances of macular pucker require no treatment. People often adapt to the mild visual distortion and can continue to perform their usual activities of daily living. Occasionally, the scar tissue forming the macular pucker can lift off the retina, permitting the retina to smooth out with improvement of visual symptoms.
Because peripheral vision remains intact, patients will not go completely blind from a macular pucker alone. If one eye has a macular pucker, there is only a small chance that pucker will develop in the other eye. Some patients wonder if the “strain” placed on the good eye can contribute to poor vision in that eye, but this is not the case. When vision worsens to the point that a patient is very bothered by the macular pucker, the treatment is surgical.
Generally, there is nothing that can be done to avoid developing macular pucker. Diet and exercise do not contribute to the formation of macular pucker. There are no eye drops or vitamins that can prevent macular pucker. Occasionally covering each eye to test the fellow eye alone is the best way of detecting a change in central vision. In addition, having a regular, annual eye exam is the best way to catch macular pucker in its early stages.
The treatment is surgical. Surgeons will perform a vitrectomy, a procedure in which the vitreous gel is removed from the center of the eye. During a vitrectomy the surgeon makes three small ports in the eye wall: one for an infusion of fluid to maintain the eye’s shape, one for a small fiber-optic light, and one for an instrument such as forceps, a laser probe, or a vitrector which removes the vitreous gel. The surgeon uses an operating microscope and lenses to look through the patient’s pupil to the retina. After the vitreous is removed, the surgeon will peel away the scar tissue on the surface of the retina. The procedure is normally performed under local anesthesia and as an outpatient. There is usually very little postoperative pain. Many surgeons employ 23- or 25-gauge instrumentation which does not require any sutures.
Most patients appreciate an improvement in vision after the surgery, but few would say that their vision returned to “normal”. Often the most significant improvement is a reduction in central visual distortion, rather than in measured visual acuity. Visual recovery usually occurs gradually and can take up to three months. It is important to note that having a vitrectomy accelerates the formation of a cataract. Sometimes, it is not until after a patient has had their cataract removed months after surgery that the patient realizes his or her best vision.
Risks of any eye surgery include infection, retinal detachment, and worse vision than before the surgery. It is possible that the scar tissue on the retinal surface will not be completely removed. Because this type of surgery is delicate and challenging, many doctors will wait until visual acuity is 20/50 or worse before suggesting surgical treatment.
Author: Allen C. Ho, M.D.
Andrew Lam, MD