While natural corneas from donors continue to be the main source for transplants, such tissue can trigger a variety of problems, including rejection by the immune system as well as difficulties such as scarring from infections or out-of-control growth of blood vessels. For years doctors have worked to develop an artificial cornea, known as a keratoprosthesis or a "K-Pro," that bypasses some of the problems that come about with natural tissue.
Aquavella himself stopped doing procedures with artificial implants for several years because of the poor results and high rates of complication. Meanwhile, Aquavella's former mentor, Claes Dohlman, M.D., of the Massachusetts Eye and Ear Infirmary, was evaluating new types of designs, eventually devoting decades to the project. When Dohlman unveiled a new design a few years ago, Aquavella tried it in several patients.
"Immediately we noticed an enormous difference," said Aquavella, one of the world's leading corneal surgeons. "After traditional cornea transplant surgery, usually it takes a year or 18 months for the patient to see well. With this device, within the first week or so, the patient will see as well as they're ever going to see. While astigmatism often limits the quality of vision with traditional corneal transplant, this new device produces no astigmatism and a clearer image."
Aquavella evaluated the recent progress in an unusual study, with himself serving as the common point as he compared the outcomes of 31 patients who received artificial corneas in procedures he performed from 1975 to 1981, to the outcomes of 25 patients who received the newer implant from 2003 to 2005. About half the patients in each group eventually recovered vision of 20/200 or better, with the newer group experiencing far fewer complications and infections. In both groups, though, Aquavella said the quality of
Source:University of Rochester Medical Center