Keratoconus surgery can be as simple as removing a scar that hinders rigid contact lens use to a corneal transplant. Other treatments include the insertion of rings into the cornea to flatten an area that bulges and causes blurred vision. Implantable contact lenses correct vision for some people who undergo keratoconus surgery, while collagen cross-linking can stop the progression of keratoconus in some patients.
An uncomplicated keratoconus surgery involves the implantation of rings into the cornea to correct myopia or astigmatism. Two plastic rings are used to flatten the part of the cornea that is abnormally curved. Lasers make tunnels before the rings are inserted. This form of keratoconus surgery can be effective for someone whose vision cannot be corrected by eyeglasses, and who cannot wear hard contact lenses. The surgery takes about 15 minutes and is done on an outpatient basis.
Another option for those who find hard contact lenses uncomfortable is called phototherapeutic keratectomy. A surgeon uses a laser or metal blade to remove a scar or bump on the cornea that rubs against a contact lens. This type of keratoconus surgery might allow the patient to tolerate a rigid contact lens to improve vision.
Collagen cross-linking, not widely used in some areas, can be employed after laser surgery to stabilize the cornea, and is used with or without implanted rings. In this method of surgery, the top layer of the cornea is removed, vitamin drops are placed on the cornea, and then ultraviolet (UV) light floods the eye. The UV light increases the number of fibers that stiffen the cornea. This procedure takes about a half-hour, and vision typically improves in three to six months.
If there is extensive scarring on the cornea, or the curve of the cornea is too pronounced for contact lenses, a corneal transplant is the only option for those seeking keratoconus surgery. Research has shown a very high success rate for cornea transplants, but the number of donors may not meet the demand of potential recipients. Some insurance policies may not cover corneal transplants.
The cornea covers the iris, the colored part of the eye, and normally is smooth, with slight rounding in the center and flatness on the edges. Light enters the cornea and passes through the retina, which sends signals to the brain to focus the object in sight. In patients with keratocunus, the cornea may be thin, steep in the center, and have an irregular surface.
Wearing glasses cannot correct keratoconus, but hard contact lenses may for those who can tolerate the discomfort. The condition usually starts in puberty and may or may not worsen in one eye or both. There is no way to predict how the disease will progress or who will be affected. Genetics are linked to keratoconus in about 15 percent of patients.