[charlesbahn]

This is an (older) treatment for macular degeneration- formation of scar tissue in the back of the eye. The laser activates the chemical (visudyne) injected into the bloodstream to try to stop the formation of the blood vessels that cause the scarring. It was the first surgical treatment for macular degeneration that was shown to be statistically helpful in preserving vision with macular degeneration (high dose vitamins can also be helpful).

This said, the results with "PDT" have not been spectacular, and it is expensive. Most recently a better treatment has become available, the use of Macugen (and other) chemicals that are injected directly into the eye. Sounds horrible, but in skilled hands it doesn't hurt, and has proven much better at treating macular degeneration. It is expensive but it also does work a lot of the time.

Personally. I haven't been terribly impressed with PDT. The most important thing is that your father is being treated by a retina specialist that does a lot of these treatments. If the Macugen-like treatments are an option, they are usually more effective.

There may be special considerations in your father's case that may make PDT a more viable option. I would be comfortable with it if recommended by an experienced retina specialist. I'd be much less comfortable that it is the right way to go if it is recommended by someone who is not.

P.S. I am an ophthalmologist, but not a retina specialist.

Charles