Photodynamic Therapy for Age-Related Macular Degeneration
What is photodynamic therapy for age-related macular degeneration?
Photodynamic therapy is a treatment for the eyes. It uses lasers and a special medicine that works when exposed to a type of light. It is done to treat age-related macular degeneration (AMD).
The retina is the layer of cells in the back of your eye that converts light into electrical signals. Your retina then sends these signals to your brain. AMD affects your macula. The macula is the sensitive, central part of your retina. This area is responsible for the detailed vision in the middle of your visual field. AMD damages your macula. The macula may become thinner and have deposits of material. Blood vessels may start growing into your retina. This can cause fluid to leak beneath your macula and your retina. This excess fluid can lead to vision loss.
Just before the procedure, an eye doctor injects a medicine into a vein in your arm. This medicine is sensitive to light. It collects in the abnormal blood vessels under your macula. You are then given a local anesthetic that affects only your eye area. Using a special contact lens, the doctor then shines a laser into your eye. The light from the laser activates the medicine. The medicine then creates blood clots in your abnormal blood vessels. This seals off the vessels. This can help prevent more vision loss.
Why might I need photodynamic therapy for age-related macular degeneration?
Photodynamic therapy is one type of treatment for AMD. This is a common cause of significant visual impairment in older adults. Rarely, it can result in total blindness. Because it affects your macula, you may still have your peripheral (side) vision if you have AMD. It may cause a sudden or a gradual loss of central vision.
AMD comes in two main subtypes: dry type and wet type. Abnormal blood vessel growth is present in only the wet type. Experts recommend photodynamic therapy only as a potential therapy for the wet type of the disease.
Photodynamic therapy cannot restore vision that you have already lost. But it may slow down the damage to your central vision.
Photodynamic therapy is an option only for certain people with wet type AMD. It may be advised if your vision loss comes on slowly over time, instead of suddenly. The treatment is used less often now that there are new drugs to decrease abnormal blood vessel growth. But your healthcare provider may advise the therapy in addition to these new drugs.
What are the risks of photodynamic therapy for age-related macular degeneration?
All procedures have risks. The risks of this procedure include:
- Temporary loss of visual sharpness (which rarely is severe)
- A new blind spot
- Reactions where you had the light-activated medicine injected
- Back pain (related to injection of the medicine)
- Photosensitivity reactions like sunburn (if exposed to direct sunlight right after the procedure)
Your risks may differ according to your age, your other medical conditions, and the specific anatomy of your AMD. Ask your healthcare provider about your risks for the procedure.
The effects of the therapy are often short-term. This is because the abnormal blood vessels may open up again.
How do I prepare for photodynamic therapy for age-related macular degeneration?
Ask your healthcare provider what you need to do to prepare for photodynamic therapy. Ask whether you need to stop taking any medications before the procedure. Also ask when you need to stop eating and drinking before the procedure.
Your provider may want to use special instruments to shine a light in your eye and examine the back of your eye. You may need to have your eyes dilated for this eye exam. Your provider might order other special tests to get even more information about your eye. These might include:
- Fluorescein dye retinal angiography
- Optical coherence tomography
- Fundus autofluorescence
Before the procedure, a healthcare provider will put eye drops in your eye to dilate your pupil. It will stay dilated for several hours after the procedure.
What happens during photodynamic therapy for age-related macular degeneration?
It is most often done as an outpatient procedure in a doctor’s office or eye clinic. During a typical procedure:
- A healthcare provider will give you an injection of the light-sensitive medication.
- You will be awake during the procedure. You may receive a medication to help you relax.
- A healthcare provider will give you anesthetic eye drops to make sure you don’t feel anything.
- A provider will place a special contact lens on your eye. This helps the laser focus on exactly the right spot on the back of your eye.
- Your eye care professional will shine the laser in the exact spot in your eye. This will activate the light-sensitive medication and cause it to form blood clots in the abnormal vessels below your macula. This seals off the abnormal blood vessels.
- Someone may temporarily cover your eye.
What happens after photodynamic therapy for age-related macular degeneration?
Ask your healthcare provider about what you should expect after your procedure. You should be able to go home the same day. Plan to have someone go home with you after the procedure.
For a few days after the procedure, your eyes and skin will be more sensitive to light. (This is due to the light-sensitive medication.) During this time, you will need to stay indoors and avoid direct sunlight. If you must go outside, use dark glasses and protective clothing. Ask your provider when it is safe for you go outside again.
Your eye may be a little sore after the procedure. Talk with your doctor about taking over-the-counter pain medication. Be sure to follow your eye care doctor’s orders about eye care and medications.
You will need close follow-up with your healthcare provider. He or she will monitor you for complications and continue to manage your treatment for AMD. Be sure to tell your provider right away if you have decreased vision or increased eye redness, swelling, or pain. Your vision may be temporarily blurry for a while after the surgery, but this often goes away.
Before you agree to the test or the procedure make sure you know:
- The name of the test or procedure
- The reason you are having the test or procedure
- The risks and benefits of the test or procedure
- When and where you are to have the test or procedure and who will do it
- When and how will you get the results
- How much will you have to pay for the test or procedure