Eye and Vision Care

Photo Dynamic Therapy?

04/07/2000

Question:

What can you tell me about Photo Dynamic Therapy? Does it help with AMD? Can it reverse the condition? Can it prevent AMD?

Answer:

There are two types of age related macular degeneration.
In one type of age related macular degeneration, new blood vessels develop. This form of macular degeneration results in the most severe vision loss. These blood vessels (called choroidal neovascular vessels) are typically fragile, and tend to break and bleed. This bleeding creates more damage in the retinal tissue. Photodynamic therapy attempts to destroy these new, leaky blood vessels.
The procedure has also been used to treat cancer.
In the case of macular degeneration, a drug is injected into the blood stream and collects in the neovascular vessels. When light is shown onto the vessels containing the drug, the vessels are destroyed. This procedure, if successful, represents an alternative to laser surgery. The laser can destroy retinal tissue when applied, but this problem might be avoided with photodynamic therapy.
The procedure has been successful in experimental trials, but to the best of my knowledge has not yet been approved by the FDA. I am also unsure whether the success rate of the procedure has been compared to laser surgery, so I cannot comment specifically on whether the procedure is more effective at halting the progression of age related macular degeneration compared to laser surgery.

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Response by:

Nicklaus Fogt, OD, PhD
Associate Professor of Optometry
College of Optometry
The Ohio State University