One Birmingham physician has become a national pioneer in his development of a new surgical technique to treat pterygium, a benign thickening of the conjunctiva of the eye that grows onto the cornea. The growth can cause visual disturbances by disrupting the normally smooth surface of the cornea.
Conventional surgery for this condition is completed by putting four to six sutures in the eye, which can be irritating to the patient and also can create a portal for bacteria growth.
Dr. Roswell Pfister, director of the Eye Research Laboratories at the Alabama Eye Bank, was the first person in the United States to employ a new technique for pterygium removal by self transplanting a patient’s stem cells to heal the eye and using the biological adhesive Tisseel® to close the incision.
“I knew Tisseel had been used in cardiovascular surgery and other operative procedures, so I developed the technique and have been using it for about 10 years,” said Pfister, who is also past chairman of the Department of Ophthalmology at the University of Alabama and past chief of ophthalmology at the Callahan Eye Foundation.
Pterygium is caused by ultraviolet radiation from the sun that damages stem cells around the limbus. The damage causes conjunctival cells to spill onto the cornea, resulting in the abnormal growth. “If you just remove the growth and leave the break in the stem cell ring and allow the eye to heal, pterygium will occur in 60 to 70 percent of the cases. While other strategies have been used to prevent the recurrence, I believe replacement of the stem cell layer is the most effective,” Pfister said.
More than 120 patients have benefited from Pfister’s procedure, which involves removing the abnormal tissue from the cornea and nasal sclera where most pterygium grows. “As we excise the growth from the cornea, we allow the tissue to retract, which exposes the defects in the conjunctiva and the limbus,” Pfister said. “I then go to the upper outer quadrant, in the case of growth on the nasal sclera, and remove a piece of tissue — including the stem cells — to replace the damaged stem cells.”
In place of stitches, Pfister uses the tissue adhesive, allowing him to secure the conjunctival autograph in seconds as compared to minutes with the conventional method. He injects the adhesive under the excision flap and removes excess with a spatula. He then uses forceps to pull together the sides of the incision to seal the entire defect. Post-operative antibiotics and steroids assist in the healing process.
“The incidence of recurrence using this method is almost zero,” he adds. “Of all of my patients, I’ve had only one where regrowth occurred and that was because she continued unhealthy exposure to the sun.”
As other physicians have learned of Pfister’s surgical technique, many have adopted the approach. “Many doctors still believe that pterygium has a high incidence of recurrence, but the new data using this technique negates that impression,” he said. “They can feel more secure sending us patients who, years ago, would have had a 60-percent chance of recurrence. We can reduce that chance to a small possibility.”
For certain patients who have severe pterygium or a recurrence elsewhere in the eye, Pfister uses mitocycin, a radio magnetic drug that gravely inhibits the growth of stromal tissue. “I soak a sponge in the drug for two minutes and then apply it at the limbus before I place the transplanted tissue. I then seal the incision as before. The mitocycin is a deterrent to regrowth,” he said.
The invasion of pterygium in the eyes is a big problem, Pfister explained, because many people are sun worshippers and expose their skin and eyes to damage from the sun over a number of years. He recommends that everyone wear quality sunglasses that block ultraviolet rays. “You should also wear a hat,” he added. “Together with the glasses, it will help protect you from developing pterygium and cataracts.”
Pfister added that while this condition is a growing problem, it is one that can be solved. “I like a problem that’s solvable. There are a lot of things we can’t do, but more and more we can take those things and convert them to issues we can solve,” he said. “It’s a fulfilling type of approach to deal with severe problems and reduce them to manageable problems using new scientific technology and surgical acumen.”
September 2007