The Boston Keratoprosthesis (“K PRO”)
Many people with corneal disease can be helped by regular corneal transplantation using tissue transplanted from human donors. However, in some cases, such transplantation is hopeless, or nearly so. In these situations, a small number of institutions in this country and elsewhere have resorted to the implantation of a keratoprosthesis of plastic material that serves as an artificial cornea. In effect, the prosthesis provides a clear window in the clouded cornea. Although this idea is obvious and has been tried for a long time, it has taken much research and clinical trials to develop prostheses that can be tolerated by the eye over a long period of time.
The keratoprosthesis that was designed by Claes Dolhman, MD, Ph.D., at the Massachusetts Eye and Ear Infirmary, is made of medical-grade polymethylmethacrylate—the same material that is used in contact lenses and in intraocular lenses after cataract surgery. The device is shaped like a collar button and it is inserted into a corneal graft. This graft-prosthesis combination will then replace the patient’s cloudy cornea. If the natural lens is in place, it is also removed. Finally, a soft contact lens is applied.
Most candidates for keratoprosthesis have little eye inflammation (after corneal edema, trauma, infection, transplant failures, etc.), and prognosis for a keratoprosthesis is very good. The majority of such patients do very well for a long time and the vision as a rule becomes much improved. Infections are very rare as long as prophylactic antibiotic drops are instilled on a regular basis, usually once or twice daily, for life.
Eyes needing a keratoprosthesis often have glaucoma, requiring standard anti-glaucoma mediation, occasionally even surgical implantation of a valve shunt.
Patients with keratoprosthesis require regular ophthalmological examination. It is customary to return every month for a check-up during the first half-year. Subsequently, the intervals can be longer. Medication, usually as drops, will have to be taken for life. Also, soft contact lens wear around the clock (no discomfort) is recommended for safety.
Since 1990, several thousand of these keratoprostheses have been implanted worldwide. More than half of these patients have achieved a marked and long-term improvement of vision.
Please click on video to see and hear one patient’s incredible journey of losing most of his vision to become the 2011 US Blind Golfer’s Association National Champion.
Elliot Perlman, MD, a corneal surgeon at the Rhode Island Eye Institute, helped restore patient Mike McKone’s vision. After multiple failed corneal transplants and loss of vision in both eyes, Dr. Perlman implanted a Boston Keratoprosthesis (artificial cornea) in Mike’s right eye in 2010. After several months, Mike’s vision improved dramatically. (Read more about The Boston Keratoprosthesis (“K-Pro”)
Mike Mckone has also been involved with Insight, located in Warwick, Rhode Island, that promotes independence and opportunities for children and adults with vision loss at no cost. Insight referred Mike to Rhode Island Services for the Blind and there he was encouraged to play golf despite the barriers of his vision loss.
If you would like more information regarding the services of Insight, please contact Chris Butler at 401-941-3322.