MARATHON -- Four juvenile green sea turtles have returned to the Turtle Hospital after a veterinary ophthalmologist in Miami removed tumors from their eyes.

Dr. Lorraine Karpinski of Pinecrest Veterinary Hospital operated on the turtles last Thursday. She is pioneering techniques to treat turtles' eyes afflicted with fibropapilloma, a herpes-like virus affecting sea turtles around the world.

Karpinski, who also treats animals at Miami's MetroZoo, has also prescribed a human anti-cancer medication compounded into eye drops that is being applied to turtles' eyes to prevent regrowth of tumors.

A fifth turtle named "Hook," who has received the drug for the past month, was examined by Karpinski, who said the medication seems to be working. If "Hook" can remain fibropapilloma-free for a year, he can be released back to the wild.

If left untreated, the fibropapilloma tumors will eventually grow and blind the turtle. Turtles without vision cannot be freed because they have little chance to survive, said hospital director Bette Zirkelbach.