Corneal prosthesis restores vision in patients blinded by corneal disease -
A new review article in the June issue of Focal Points a monthly publication of the American Academy of Ophthalmology, calls keratoprosthesis a viable alternative to standard cornea transplants to help people with corneal blindness. Co-written by R. Rony Sayegh, MD, a surgeon with the Eye Institute University Hospitals, the document states that if the standard corneal transplantation is effective in treating many of the 8 million cases worldwide of corneal blindness, keratroprosthesis is an important alternative when standard treatment fails.
"There is no doubt that Keratoprosthesis helped restore vision in many patients blinded by corneal disease," said Dr. Sayegh, who is also assistant professor of ophthalmology Case Western Reserve University School of medicine, who co-authored the paper with Natalie A. Afshari, MD, Professor of ophthalmology and head, Division of cornea and refractive surgery of the Shiley Eye Center, University of California , San Diego, La Jolla, Calif. a corneal prosthesis is a surgical device that is assembled with a given cornea and transplanted to replace corneas severely damaged or diseased. the surgery is relatively rare and is performed to restore vision in patients corneas severely damaged due to congenital birth defects, infections, inflammation, injury and chemical burns.
the most widely used device for this procedure in the US is the prosthesis Boston (Boston KPro). It consists of a front plate with a clear plastic rod, which houses the optical part of the device, a rear plate, and a titanium locking ring. Each year, only about 0 patients in the US receive KPro compared to 36,700 corneal transplants nationwide.
"The KPro is reserved to a small but significant number of people who are blinded by severe cornea conditions," said Dr. Sayegh. "If a patient undergoes several standard cornea transplants, blood vessels unhealthy can develop leading to a rejection of the transplanted cornea, making it impossible to keep the grafts clearer standards for vision. the Boston KPro and other prostheses can give these people a last chance to have his sight and be able to function independently again. "
Dr. Sayegh has recently begun testing a new design for the K-Pro that has a titanium back plate that joins via a new trigger mechanism for the rear plate to fit on the front plate, which avoids the need for an additional locking ring.
"the new design eliminates added piece and makes it easier for the surgeon to assemble the device," said Dr. Sayegh. "More importantly, fewer components can result in improved the overall safety of the procedure, and it is likely that this design update will become the new standard. "
many members of the cornea service at university hospitals studied and helped the development of keratoprosthesis Boston. the availability of this technique for residents of Northeast Ohio has helped a number of patients regain vision after many years of blindness.
Dr. Sayegh said that there are other types available keratoprostheses, and we chose a surgeon must depend on the patient's needs and the severity of his condition.
"the most effective devices tend to have a more wide range of indications, are less expensive and are easier to surgically implant, preferably in a single step by a single surgeon, employing techniques familiar to most surgeons. Good anatomical retention and ability to restore the best achievable visual potential are other important factors for the success of corneal prosthesis. Lastly, a favorable safety profile with a low occurrence of complications, particularly those threatening the view is of the essence. clinicians should be able to identify appropriate candidates for the procedure, and the choice corneal prosthesis used must be adapted to the patient's specific condition, "he said.
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