An unhealthy cornea prevents light from entering the eye, which can cause blurred vision, or in advanced cases, blindness. This occurs when the cornea is swollen, or scarred, or irregular as in the disorder known as Keratoconus.
Cornea transplantation can successfully replace these unhealthy corneas with a healthy new one and restore vision. The corneal transplant is a wonderful procedure and has restored eyesight to millions. The most common reasons for undergoing a corneal transplant are to improve vision, reduce pain, or to maintain the structural integrity of the eye. Cornea transplants have been performed for several decades and approximately 40,000 are done in the USA yearly. New understandings and therapies of eye surface disease in tandem with advances in cornea transplantation have allowed for greater cornea transplant success than ever before.
With a conventional corneal transplant, the full thickness of the central 7-8 millimeters of the cornea is completely removed. A whole new donor cornea that has been prepared by an eye bank is carefully sutured in place with very fine stitches. These stitches can remain in the eye for over a year. You will not have any pain during the procedure or see the surgery while it is happening. On the day of surgery you will go home with a patch and shield over your eye. You will need to be seen one day after surgery, then one week after that, and then every 3-6 weeks, depending on how the eye is healing.
Unlike cataract surgery, where visual recovery is rapid, the healing time after a full thickness corneal transplant can take between 6 months to over one year before the best vision is obtained. The stitches used often cause the cornea to take on an irregular shape during the healing process that must be corrected with glasses or contact lenses.
Careful postoperative management is critical to ensure the success of the transplant. It will require you to take frequent visits to the doctor to measure the cornea, prescribe glasses or contacts, and remove the stitches over time. You must also use eye drops to prevent infection or rejection of the transplant, most likely for many years. Graft rejection occurs in approximately 10% of patients. This needs to be treated aggressively with steroids and usually heals. Occasionally, there are problems with sutures which can come loose, cause infections, or cause astigmatism. The astigmatism after traditional corneal transplant surgery can be significant enough that eyeglasses alone won’t give adequate vision. These patients may ultimately require contact lenses or additional surgery to reduce or eliminate the astigmatism. Eyes with a transplant are also more at risk from minor trauma. It is important to wear safety glasses at work or during sports.