Photodynamic Therapy for Age-Related Macular Degeneration

Photodynamic therapy is a technique to treat certain kinds of macular degeneration. The procedure involves using a special intravenous (IV) medicine that can be activated by laser light. When activated, the medicine can close abnormal blood vessels and reduce your chance of losing vision.

Photodynamic therapy is used for some people with certain kinds of wet, age-related macular degeneration and similar conditions. These people have abnormal blood vessels growing underneath the tissue at the back of the eye (retina) and most often lose their central vision.

If your eye doctor finds abnormal blood vessels directly under the center of your retina, you will probably have a special test called a fluorescein angiogram to determine the type, the size, and location of the abnormal blood vessels. Your doctor will use the results of the angiogram to help determine if this treatment will work for you.

Because the medicine used in the procedure is activated by light, it is important to bring clothing that will protect your body from sunlight after the procedure. You will need long pants, a long-sleeve shirt, gloves, and hat. Make sure your doctor has your medical history so he or she doctor can check what other treatments you have been given. It is also important to tell the doctor if you have any unusual medical conditions or are taking medicine that makes you sensitive to light (such tetracycline medicines) or any liver diseases such as cirrhosis or porphyria.

Do not wear eye makeup on the day of the procedure.

First, your doctor will review or possibly take a new fluorescein angiogram to measure the size and position of the abnormal blood vessels. You will be weighed and measured to figure out the dose of the light-sensitive medicine (called Visudyne) you will need. The medicine will be given through a vein with an IV line for about 10 minutes. Some people have temporary back or chest pain while getting the medicine. The doctor will then place a drop of anesthetic medicine in your eye. He or she will then put a contact lens on your eye and ask that you place your head comfortably on a small platform in a slit-lamp instrument. Five minutes after the medicine is given, the doctor will direct a laser beam to the area of abnormal blood vessels for just over a minute. This is painless, but requires that you hold relatively still. After the laser is turned off, the contact lens and IV are removed, and the procedure is done. It may take a few minutes for the blurry vision caused by the laser to go away.

Because you were given light sensitive medicine, you will need to avoid exposing yourself to sunlight and bright indoor light for 5 days. Your doctor will give you a kit containing special protective glasses to keep the sun out of your eyes. Regular sunglasses and sunscreen will not protect you. You should wear pants, a long-sleeve shirt, a hat, and gloves when you are outside. Avoid bright indoor light and sunlight coming in from windows. Don't worry about light from fluorescent, incandescent, or halogen light bulbs that are used indoors. They are too weak to activate the drug. Your provider may give you a wristband to wear for the next 5 days describing the treatment you had.

A follow-up appointment for an exam and another angiogram will be made usually 6 to 12 weeks after the procedure. Most people require more than 1 treatment of photodynamic therapy. Sometimes 5 or 6 treatments over the course of a year or so.

For some specific forms of age-related macular degeneration, photodynamic therapy has been shown to reduce the risk of losing more vision over time. This, however, applies only to some kinds of abnormal blood vessels. The treatment usually does not improve vision.

The major risk of the procedure is photosensitivity. It is important to remain protected from sunlight and bright indoor light for 5 days after a treatment to avoid possible severe sunburns. Operating room lights can also activate the drug. So, you should avoid scheduling surgery during this time. The wristband provides information for emergency doctors should you need emergency surgery during this time. You will probably have some changes with your vision that come and go after treatment. Rarely, severe vision loss occurs soon after a photodynamic treatment.

Call your eye doctor's office if you experience any major unexpected problems after treatment, such as hives, difficulty breathing, sudden loss of vision, or a severe sunburn. These problems, however, are very rare.