Retina

Age-related macular degeneration (AMD) is the leading cause of vision loss in people over the age of 50 in the United States. This eye disease affects the macula, the central part of the light-sensing nerve tissue in the eye known as the retina. The macula provides the sharp, straight-ahead vision that allows you to see small detail, read fine print, recognize faces and see street signs.

There are two types of AMD - the dry (atrophic) form and the wet (exudative) form. The dry form of AMD affects about 90 percent of AMD patients and usually begins with the formation of tiny yellow deposits called drusen in the macula. Drusen usually do not cause serious loss of vision, but can cause distortion of vision. However, for reasons that are not yet understood, sometimes drusen will cause the macula to thin and break down, slowly leading to vision loss.

The wet form of age-related macular degeneration occurs in about 10 percent of patients. It is caused by the growth of abnormal blood vessels beneath the macula that can leak fluid and blood. Wet AMD typically causes significant vision loss. Age-related macular degeneration is the leading cause of vision problems in the affected eye and can progress very rapidly, causing permanent central vision loss.

The exact cause of AMD is not known. AMD may be hereditary. If someone in your family has or had AMD, you may be at higher risk for developing the disease.

A primary symptom of AMD is a distortion in vision that makes straight lines appear wavy or irregular. Patients also may notice blurriness and dimming of vision, a dark or blank spot in the center of their vision, or that the size or color of something looks different when viewed through different eyes.

Your ophthalmologist will perform a complete clinical examination to diagnose AMD. He or she may order a fluorescein or indocyanine green angiogram to look for the abnormal blood vessels within or under the retina. During each of these procedures, dye is injected in the arm, and photographs (not X-rays) are taken from a special camera to track the movement of the dye as it reaches the eye and to show any changes in the retina. These photographs will serve as a guide for treatment.

Many national eye centers, including The Cleveland Clinic Cole Eye Institute, are investigating new medications and other ways to treat AMD. Although there currently is no medical or surgical treatment for the dry form of AMD, eyesight may be helped with low-vision aids that use special lenses or electronic systems to produce enlarged images of nearby objects. Patients also can be trained to use their peripheral (side) vision to help them see more clearly. One recent study found that taking high levels of antioxidants can reduce some patients' chances of developing AMD. Ask your eye doctor if this type of therapy is right for you.

Because the dry form of AMD can change into the wet form, it is very important for patients to monitor their eyesight carefully and see their ophthalmologist on a regular basis.

For patients with the wet form of AMD, early diagnosis and treatment are critical to save as much vision as possible. Early diagnosis can help expand treatment options and increase the likelihood of preserving eyesight.

Several options are available to treat the wet form of AMD, but not all are appropriate or successful for all patients. These treatments include:

• Photodynamic therapy - combining the use of a cold laser with a light-sensitive drug to destroy abnormal blood vessels. The drug is injected into the arm and travels to the unwanted vessels in the eye. This helps avoid damage to healthy retinal tissue.
• Laser therapy - the use of high-energy lights to destroy actively growing abnormal blood vessels.

Cole Eye Institute is also testing several experimental treatments for AMD for patients who qualify for these studies:

• Anti-angiogenesis medications - There are several drugs that prevent the growth of abnormal blood vessels currently being tested.
• Surgery to remove abnormal blood vessels and blood - The surgeon may use a genetically engineered enzyme called tissue plasminogen activator (t-PA) to dissolve any blood clots under the macula.
• Macular translocation - This new procedure may be performed if there are abnormal blood vessels directly under the center of the macula, where a laser beam cannot be placed safely. Here, the surgeon rotates the retina away from the abnormal blood vessels to an area that is healthy, thus preventing the formation of scar tissue and further damage to the retina. Then, laser therapy is used to treat the abnormal blood vessels.

After the surgeon removes the abnormal blood vessels or moves the retina, an air bubble is placed in the eye so the retina can heal properly. The patient must remain in certain positions (e.g. upright, laying down or sitting to one side) for several days following macular surgery, until the body has absorbed the air bubble.

Once the doctor can examine the eye after macular surgery, they may order another angiogram to make sure there are no additional areas of blood leakage. If any problem areas are observed, the doctor may perform additional laser treatment.

As the eye continues to heal over the next three to six weeks following macular surgery, you are treated with eye drops to reduce inflammation, keep the eye comfortable and prevent infection. Once the eye has healed, you are fitted for glasses and any necessary low-vision aids.

Depending upon the cause of legal blindness, it is possible that surgery may help. If recent bleeding or leakage under the retina has resulted in legal blindness, surgery can be considered.

Because bleeding or leakage may occur beneath the retina even following the laser treatment, it is possible that surgery can help.

Rare complications may include infection, elevation of pressure in the eye (glaucoma) or damage to structures in the eye including the acceleration of clouding of the lens (cataract). In very rare instances, retinal detachment or severe loss of vision may occur.

As long as you can maintain a face-down position for several days following the surgery and you are not prone to excessive bleeding during surgery, other medical conditions or age should not be a factor if you are considered an appropriate candidate for surgery. Your Cole Eye Institute vitreoretinal specialist will work closely with your other doctors to be certain that your other medical conditions are treated and controlled as best as possible before, during and after surgery.

• Make an appointment now.

You can also call 216.444.2020 or 1.800.223.2273 Ext. 4-2020 to schedule an appointment with a Cole Eye Institute ophthalmologist.

The eye is often compared to a camera. The front of the eye contains a lens that focuses images on the inside of the back of the eye. The back of the eye, called the retina, is covered with special nerve cells that react to light. These nerve cells are very close together in the middle of the retina where the eye focuses the images that we see. This small middle section, called the macula, is essential to clarity and sharpness of vision. Sometimes the retina is damaged by unwanted new blood vessels growing on it. This damages the macula and causes vision loss.

In macular translocation, the macula is moved away from abnormal new blood vessel growth (choroidal neovascular membrane) to an area of healthier retinal tissue to preserve as much vision as possible.

This procedure is only for patients who have the wet (exudative) form of age-related macular degeneration. This translocation is used only for patients whose abnormal blood vessels are located in the very center of the macula and are not associated with a scar. Better results are achieved in patients who have small abnormal blood vessels of more recent onset.

Will the patient need tests before the procedure?

The patient will require a comprehensive ophthalmological evaluation as well as fluorescein angiogram. Sometimes an indocyanine green angiogram is also needed.

This is a vitreoretinal surgical procedure - a bubble of air is placed in the eye and the patient is required to maintain a sitting up or leaning to one side position for a few days following the surgery.

In about 10% of the cases, a secondary macular translocation treatment is required.

The treatment is still experimental. So far, about 20 percent of the patients treated have had improvement in the vision. There continues to be improvement up to six months after the procedure.

No.

Yes.

The patient needs to be evaluated at the Cole Eye Institute to determine whether they are eligible to undergo the procedure here.

Yes.

The risks will be discussed when the patient is evaluated.

Yes.

• Make an appointment now

Or call 216.444.2020 or 800.223.2273 Ext. 42020 to schedule an appointment with a Cole Eye Institute ophthalmologist.