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Sight restored with artificial cornea

Yale Medicine Magazine, 2009 - Autumn

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When natural transplants fail, ophthalmologists turn to corneas made from polymers.

Sixteen years ago, when Awilda Irizarry was 33, glaucoma was diagnosed in her right eye. Over the years, her vision grew increasingly blurry and the pain became agonizing. Her doctor prescribed eyedrops to reduce pressure on her optic nerve; finally, however, the pain was so unbearable that Irizarry had her eye removed.

The pain on the right side was relieved, but Irizarry began to feel pain and lose peripheral vision in her left eye. She had four surgeries, including two donor cornea transplants, but still her vision dimmed and the pain worsened.

“She doesn’t like people to help her much,” said Irizarry’s daughter, Maggie Morales. “She loves being independent, but she was frustrated losing her vision little by little. It got to the point where she was basically blind.”

Last August, just as Irizarry’s doctors were running out of options, Jimmy K. Lee, M.D., joined Yale as the new director of the cornea and refractive surgery sections at the Yale Eye Center. Lee, who had just completed a fellowship at the Wilmer Eye Institute at Johns Hopkins Hospital in Baltimore, came with a clinical interest in corneal transplantation, including artificial corneas. After hearing Irizarry’s case history, Lee thought Irizarry would be an ideal candidate for an artificial cornea transplant. “The main indication for an artificial cornea is when patients have had multiple failed natural cornea transplants,” Lee said. “The immune rejection rate is much lower because the center is an artificial implant.”

The first artificial cornea implant was performed less than 20 years ago, after the device was approved for use in the United States in 1992. “It was uncomfortable for the patient, and there were complications,” said Lee, one of a handful of surgeons in the country who perform artificial cornea transplants. The model Lee uses is the Boston K-Pro (also known as the Dohlman-Doane) developed at Harvard and Massachusetts Eye and Ear Infirmary in the 1960s by Claes H. Dohlman, M.D., Ph.D., considered the founder of modern corneal science. The K-Pro is made of a transparent polymer that offers a visual field almost as wide as that of a normal cornea—the transparent part of the eye that covers the iris, pupil, and anterior chamber and contributes to the eye’s focusing power. A donor cornea is used as a “peripheral skirt” to provide tissue into which the prosthetic implant can incorporate itself.

The surgery takes about two hours, and the bandages are removed the next day. Patients are treated with steroids and antibiotics and usually recover fully in about a year. Glasses or contact lenses are typically prescribed to enhance sight restoration.

It’s always an emotional moment when the bandages come off and a patient can see again, said Lee, who performs about two artificial cornea transplants per month. “These are patients who at best could only see light. After the surgery they can dress themselves, cook and watch TV again. There aren’t many scenarios in medicine where there’s such a dramatic change.”

Morales said when Lee removed the bandage from her mother’s eye, “she was laughing and crying at the same time” because she could see her children and grandchildren. “It’s better in every way,” Morales said. “Now she can see us.”

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