While medical science offers several conservative methods of correcting poor vision caused by corneal issues, some patients may opt for a cornea transplant when these other options can't help them. Corneal transplants, which usually involve replacing the damaged cornea with one from a human donor, are not always accepted by the body and may require lengthy recovery times, but in most cases they can restore vision to the affected eye.
A variety of problems might cause your cornea, the spherical transparent surface at the front of the eye, to stop refracting incoming light properly. These problems include keratoconus (a cone-like malformation in the cornea's shape), thinning of the corneal tissue, scarring from infections or injuries, ulceration or the clouding of the corneal surface, and a disorder known as Fuchs' dystrophy. Rarely, complications from laser vision surgery or cataract surgery might also leave you with a malfunctioning cornea.
Without the ability to correctly receive refracted light from the outside world, your retina cannot send coherent images to the brain, leading to blurred or cloudy vision. Fortunately, many corneal issues can be compensated for with corrective lenses and other technologies. But those who cannot benefit from these treatments may need to consider the possibility of having a cornea transplant.
There are two primary types of cornea transplants. The traditional kind, known as penetrating keratoplasty or PK, involves removing and replacing the full thickness of the corneal tissue. Usually a human cornea from a donor is used, but patients with a history of organ rejection may receive a synthetic cornea instead. The more recent type of transplant, known as endothelial keratoplasty or EK, removes and replaces only inner tissue at the rear of the cornea. EK makes sense when only this part of the cornea is diseased or damaged.
Recovery from a cornea transplant takes patience. You will be asked not to overexert yourself for a few weeks, and your vision in the treated eye may remain as least as bad as before for several months as the tissues heal and the eye becomes accustomed to its new cornea. Since the new cornea may not precisely duplicate the curvature of the old one, you may require corrective lenses to fully restore your vision. But as an alternative to total or permanent vision loss, cornea transplants can often repay the effort and expense involved.