Vision is one of our most valuable assets, and understanding the conditions that can rob us of this sense can go a long way toward prevention.
One such sight-stealing condition is an epiretinal membrane (ERM). It has been estimated that about 30 million people in the United States have an epiretinal membrane in at least one eye. And, without proper diagnosis and observation, ERMs can quickly decrease vision—and the quality of life that being able to see affords us.
What is it?
An epiretinal membrane (ERM) is a thin sheet of semi translucent, fibrous scar tissue that forms over the macula— the area most responsible for sharpest eyesight—and distorts vision. ERMs most often cause minimal symptoms but in some instances can result in a painless loss of vision and visual distortion.
The back of the eye naturally contains a vitreous gel. Normal cells derived from the retinal and other tissues may shed into the vitreous gel and eventually settle onto the surface of the macula. These cells can form a membrane that, in many instances, remains very mild with no real effect on the macula or vision.
In other cases, however, the membrane may slowly become more prominent on the inner surface of the retina. Also known as a macular pucker, surface wrinkling or cellophane maculopathy, this thin film can contract, causing pulling or puckering of the retina. It is this wrinkling and contracting that causes distorted and blurred vision.
Many patients experience an ERM in a single eye. ERMs usually do not affect both eyes at the same time or in the same way.
Symptoms and diagnosis
Epiretinal membranes often have very few symptoms, and patients typically have normal or near-normal vision. Generally ERMs are most symptomatic when the membrane affects the macula. As the condition slowly progresses, visual distortion may occur, such as:
- Difficulty seeing fine details or reading small print
- Noticing straight lines appearing as wavy
- The development of a gray area or blind spot in the center of vision
Less common, more advanced forms of ERMs symptoms may include:
- Double vision
- Light sensitivity
- Images appearing larger or smaller than they actually are
Epiretinal membranes are often diagnosed during an eye exam when drops are used to dilate the pupil for examination of the retina and optic nerve. ERMs can be further evaluated with a diagnostic machine such as the OCT technology used at Island Retina. The Spectral Domain Optical Coherence Tomography (OCT) allows a non-contact scan of the retina’s anatomy, allowing doctors to detect and diagnose numerous eye problems, including epiretinal membranes. Quick, easy and convenient, the imaging test requires a few eye drops for dilation and only 10 minutes of time.
Use of screening technology like the OCT can often detect damage in the eyes before it may appear in a traditional eye examination.
What causes it?
The risk of developing ERM increases with age and with predisposing ocular conditions. The most common cause of ERM is an age-related condition called posterior vitreous detachment (PVD). In these instances, the vitreous gel filling the eye separates from the retina resulting in micro-tears and symptoms of floaters and flashers.
Other conditions increasing the risk of ERM include:
- Age-related changes in the eye of adults aged 50 and older
- Retinal tears or detachment
- Blockage of blood vessels
- Inflammation in the eye
- Prior eye surgery
- Eye trauma
Epiretinal membranes are usually stable after the initial period of growth and do not cause vision issues. Most often, they are kept under observation and monitored by anophthalmologist to ensure they do not have any future effects on vision.
There are no eye drops or medication for ERM. The only treatment is a surgical procedure called a vitrectomy. With significant symptoms, surgery may be decided upon to improve poor vision. Surgery is not necessary if the ERM is mild and has little or no effect on vision.
An eyecare professional will assess the symptoms in their decision whether or not surgery is the right option. The main symptoms for surgery recommendation are if blurring and distortion of vision is interfering with the daily life and activities of the patient.
A vitrectomy surgery involves removal of the membrane to allow relaxation of the macula for improved vision. It is completed on an outpatient basis under local anesthesia in about an hour. The surgeon will create a few, small incisions in the white of the eye. The vitreous gel filling the inside of the eye will be replaced with a sterile saline solution, not causing any permanent harm but allowing access to the retina’s surface. The ERM is then carefully removed with specialized forceps. After removal of the membrane, the small incisions will close and heal on their own, usually not requiring any stitches.
An eye patch will cover the healing eye until the next day, and eye drops or ointment will be necessary for several weeks. Post surgery, patients can usually resume normal, non-strenuous physical activities within 24 hours, however driving, returning to work and other visual tasks will vary from person to person.
Most patients have minimal discomfort after surgery that is manageable with acetaminophen.
Most patients will find they have improved vision post surgery. However, a small percentage, even after a successful, uncomplicated surgery, may not have improved distortion in the vision experienced prior to surgery. The successful outcome of the surgery can be affected by factors such as:
- Length of time the condition has been present
- The degree of pulling on the macula
- The cause of the epiretinal membrane
Complications of a vitrectomy
There are always risks with any surgery, and epiretinal membrane surgery is no different. Even with the most advanced surgical equipment and techniques used in performing a vitrectomy, it is important to be aware of any possible complications. The most common possible complications are:
- Bleeding in or around the eye
- Retinal tear or detachment
- Accelerated cataract progression
- No or minimal improvement in vision
- The need for cataract surgery within a year of the vitrectomy
Visit Island Retina and continue seeing clearly
Only an eye care professional can diagnose ERM. Let Island Retina continue to keep your view of the world clear. Take the first steps in fighting eye disease now by scheduling your appointment today.