The Macula, which is a specialized area of the retina, is responsible for clear, detailed vision. Epithelial Membrane or Macular Pucker is an abnormal growth of cells over the macula.
In order to maintain its round structure, the central portion of the eye is filled with a jelly-like substance known as the vitreous. As a person ages, the vitreous jell begins to shrink and becomes more condensed or shrinks. As this shrinkage and forward movement of the vitreous progresses, traction or pulling can be exerted on the retina, resulting in microscopic damage to its inner surface. When this focal area of damage or irritation occurs in the macular region, the retina initiates a healing response with mobilization and migration of cells found within the retina itself. These cells then spread outward along the surface of the retina.
This thin layer of scar tissue is known as a macular pucker. Macular pucker is known by a variety of names, including epiretinal membrane, surface wrinkling retinopathy, cellophane retinopathy, and internal limiting membrane disease. All of these names relate to the fact that there is a layer of thin scar tissue on the surface of the macula which results in a mechanical wrinkling and distortion of the retina leading to decreased vision. This membrane can often be removed (see illustration).
Clinical photo and artists drawing of macular pucker
In most cases, this healing response is mild, and results in a very thin layer of cells lying on the surface of the retina. These cells may be clear and produce no significant visual disturbance or progress to form a thicker, more opaque membrane leading to significant vision loss.
In most patients, this process is slow and self limiting and eventually the scar tissue stops proliferating or extending.
With time, the membrane in some eyes may contract causing a wrinkling of the underlying retina. When this occurs in the central, critical portion of vision, the macula, visual symptoms result.
Symptoms of a epithelial membrane
The symptoms are similar to most conditions affecting the central part of the retina, the macula. These include:
- Blurred central vision.
- Distorted, “wavy” vision.
- Difficulty reading or performing tasks that require seeing detail.
- Gray area in central vision.
- Central blind spot.
How is the diagnosis of macular pucker made?
The diagnosis of a macular pucker is made when your eye care provider performs a dilated retinal examination.
What should be done if an epithelial membrane is discovered?
In most cases, no treatment is recommended for macular pucker. This is due to the fact that the visual distortion and decreased reading ability is minimal. Although some visual problems may be noted, they are often easily adjusted to and pose only mild visual impairment. In some instances, however, the distortion and vision loss is significant. It is at this point, that we consider surgical repair.
Repair of a macular pucker or epiretinal membrane is accomplished through use of vitreoretinal surgery. Using microsurgical instruments, a procedure known as a vitrectomy, the microscopic removal of vitreous jell from the center of the eye, is performed. During vitrectomy, any vitreous attachment will be removed from the central macular region. Specialized microsurgical instruments are then used to gently peal and remove the scar tissue from the surface of the retina, relieving the traction and reducing the distortion to the retinal surface.
The surgical procedure itself is typically performed under local anesthesia, occasionally a patient will need to stay in the hospital overnight but most often they are able to return home by the end of that day. A postoperative examination within 24 hours of surgery is required in all cases. Regular follow-up examinations are performed during the first six weeks of recovery, and then at regular intervals after that. Patients typically utilize several eye drops applied to the operated eye over the course of several weeks following the surgical procedure.
Approximately 10-12 weeks after surgery, when the eye has recovered from the surgery and the macula has had a chance to return to a more normal configuration, the patient is measured for glasses. Full visual recovery may not occur for at least 3-4 months following the procedure.
As with all surgical procedures, there are potential complications and side-effects associated with repair of macular pucker. These include a small percentage of patients that develop retinal tears or detachments during the procedure or in the immediate postoperative period. These problems are usually easily repairable. In patients who have not already undergone cataract surgery, development of a cataract may occur more rapidly following vitrectomy surgery. Surgical removal of the cataract and placement of an intraocular lens is then required.
Frequently asked questions:
Macular pucker and macular hole both result from excessive traction and pulling by the vitreous on the surface of the retina. If mild to moderate traction occurs as the vitreous separates from the retinal surface, then a healing response may take place resulting in a macular pucker. However, if the traction is more severe, a true defect in the retina may occur resulting in the formation of a macular hole. Macular degeneration, on the other hand, is a distinct entity involving the tissues underlying the retina. There is no direct relationship between macular degeneration and these other two conditions.
If I have surgery, what type of vision improvement can be expected?
Typically, a vision improvement of about 3 lines in an eye chart (or 50% improvement in vision) can be achieved. This is an “average” vision improvement, however. Recovery does vary on a patient-by-patient basis. Each individual must be evaluated and discuss with their eye care physician the expectations for visual recovery. Some patients do achieve only a small amount of vision recovery, while others achieve a more significant degree of improvement. One of the major effects of surgery is a reduction in the degree of distortion that is often a major complaint of patients with macular pucker.
How soon will I get my vision back?
Vision improvement following macular pucker surgery typically occurs gradually as the eye heals. Usually there is some vision improvement noted in the first 6 weeks, but a final visual recovery is not achieved in many patients until a full 3 months has elapsed from the time of surgery. Once the macula has had a chance to heal and restore more normal function, a final prescription for glasses is given. For patients who have not had cataract surgery, vision may begin to exhibit gradual deterioration over 1-2 years following the vitrectomy for removal of the macular pucker, as a cataract develops. Once cataract surgery is performed, vision would then typically return to its maximal level.
Does the scar tissue or the macular pucker ever grow back?
In a small number of cases, the macular pucker may recur or grow back as a result of reactivation of the healing process. The reason that macular puckers grow back in some patients and not in others is poorly understood. It appears that the body recognizes the surgical procedure itself as a form of injury or irritation to the retina, and restarts the healing process that caused the macular pucker in the first place. Fortunately, instances of re-growth of macular pucker are very uncommon, and stability of vision is more typically achieved after surgery.
Please note that much of the above content was provided compliments of: Vitreous-Retina-Macular Consultants New York