Not everyone is a good candidate for a conventional cornea transplant. Patients who have suffered through rejection of their donor corneas aren't good candidates for another transplant, and this is where keratoprosthesis comes in. If one of your loved ones has suffered through a failed cornea transplant, here's what you need to know about keratoprosthesis.
What is keratoprosthesis?
Keratoprosthesis is a surgical procedure that replaces diseased or damaged corneas. It is similar to conventional cornea transplant surgery, but there is one major difference. Your loved one's diseased corneas will be replaced with artificial corneas instead of donor corneas.
Why is keratoprosthesis done?
Conventional cornea transplants aren't always successful, and with each failed transplant, the risk of another failure increases. About 21% of transplants fail in the first decade, but the replacements for these failed transplants are even more likely to fail. The initial replacement usually lasts about 12.3 months, while the second lasts 11.4 months, and the third only lasts 8.7 months. Rather than putting your loved one through multiple surgeries that aren't likely to be successful, your surgeon will recommend keratoprosthesis.
What are the artificial corneas made of?
There are a few different types of artificial corneas. Some are made of silica, a naturally occurring substance that is clear and strong. Silica is biocompatible, which means that rejection is less likely. Other artificial corneas are made from water-filled polymer. These are soft and allow nutrients to pass through, mimicking the behavior of real corneas. Some types are also made of collagen, a material that naturally occurs within the human body. All of these types have their own set of benefits, and the surgeon will carefully evaluate which type is best for your loved one.
How successful is this surgery?
Keratoprosthesis has a higher success rate than traditional cornea transplant surgery among patients who have already had failed transplants. Success rates can be as high as 90% five years after the procedure, as long as the patient follows a strict regimen. Your loved one will be prescribed a long-term antibiotics regimen and will also have to wear contact lenses. Contact lenses are important because they spread tears evenly across the eye and keep the new cornea from drying out.
Conventional cornea transplant surgery doesn't always work, but when it fails, patients have other options. Keratoprosthesis is a great option for patients in this situation, so talk to your loved one's surgeon, such as Todd S. Kirk, MD, about this procedure.