Information on Cornea Transplants

Cornea implants, or corneal ring implants, are clear pieces of acrylic surgically implanted in the corneas of the eyes. The corneas are the clear, outside shells of the front of the eye. The implants are in the shapes of half-circles, and two cover the sides of the cornea but not the center. The implants permanently flatten the cornea to help correct vision problems due to the shape of the eye. Even though they are permanent, they can be removed, especially if they create problems with night vision.

Function

• Cornea implants help correct mild nearsightedness with mild or no astigmatism. They're also used to treat cornea diseases such as keratoconus and cornea thinning. Due to restrictions imposed by the U.S. Food and Drug Administration (FDA), only adults over 21 who have had stable vision for at least one year may be considered for the implant surgery.

Features

• For treating mild nearsightedness, implants flatten the cornea to refocus the rays of light, thereby improving vision. They are currently not approved to treat moderate or severe nearsightedness. Eighty-eight percent of nearsighted implant patients have not needed glasses and contact lenses within a year after the implant surgery.To correct keratoconus, a degenerative disorder that causes the cornea to form a cone shape, the implants flatten the tip of the cone on the cornea to reduce the distorted vision. Patients with mild keratoconus usually will not need corrective lenses, but those with moderate or severe most likely will.

Post-Surgery

• The surgery is an outpatient procedure and takes only about 15 minutes to complete. Eighty to ninety to percent of all patients will have a sharp improvement in their vision within the first day after the procedure. The implants are placed underneath the cornea's nerves, so patients will not be able to feel them. Others will not be able to see them unless they look closely into a patient's eyes.

Risks

• Cornea implants have their fair share of risks and complications from the surgery. These risks include infection from the surgery, vision glare or halos, problems with night vision, overcorrection, or undercorrection. So far, there have not been any studies on long-term risks of implants so these side effects are still unknown.

Considerations

• Most people think of laser surgery over cornea implants to help correct nearsightedness, but one advantage implants have over laser surgery is that they can be removed if there are any problems. Once the laser surgery is performed, it cannot be undone. All potential patients should also be aware that not everyone is a candidate for implant surgery. Be sure to discuss all potential options to help improve your vision with your doctor.