Blindness was once an incurable, and hardly treatable, condition. In recent decades, corneal transplant has been pursued as a way of correcting certain forms of blindness, particularly those that affect the cornea – the clear outer layer of the visible portion of the eye. More than 40,000 successful corneal transplants are performed each year, according to Dr. Murat Kalayoglu of OphthalmologyWeb, but problems can persist and complicate the success of such a procedure (an estimated 60,000 are unsuccessful according to medical device companies). A shortage of corneal tissue is also an issue, as the World Health Organization estimates that approximately 10 million people could benefit from a transplant.
One solution is a more recent type of corneal transplant procedure, which also aims to restore sight – the implantation of an artificial cornea called a keratoprosthesis. The artificial cornea is a clear acrylic prosthesis implanted into the eye. A lot of work on the clinical applicability and safety of the design and procedure has been done in Boston – known as Boston Keratoprosthesis. A few other types are also commercially available for surgeons from other medical device companies.
In early December 2010, one such surgery restored one Englishman’s sight. As reported by ITN News, Norman Simpson regained sight a couple of weeks after receiving a keratoprosthesis. The man had been blind for 10 years after falling and damaging the cornea of his one good eye. He had undergone 70 prior procedures attempting to restore his sight with donor tissue, with no success until now. The surgery was performed on his left eye using a keratoprosthesis that consisted of a stabilizer ring and plastic lens. Donor tissue between the two pieces is stitched to the eye to hold the cornea in place according to Thomas Moore at SkyNews.
The 2-hour procedure was performed under local anesthetic, and surgeons hope it will no longer be only a last ditch treatment for blind patients who do not respond to other treatments. The Centre for Sight in Essex estimated that a few thousand patients could benefit from the procedure. However, the procedure can be expensive and will only help those who are blind due to corneal damage. They expect the implant to remain healthy and viable for many years with regular follow-up checks and antibiotic drops. Simpson is one of just a handful of patients in the UK to receive the transplant. In the U.S., approximately 600 Boston Keratoprostheses have been transplanted since obtaining FDA approval in 1992.