Keratoconus, which literally means "cone-shaped cornea", is a fairly uncommon condition in which the cornea becomes thin and starts to bulge. An eye affected by keratoconus will develop a pointed shape, much like the end of a football. The cause of this condition is currently unknown, but researchers believe that genetic may be a factor. An estimated 10% of people with the condition have a family member with keratoconus.
Keratoconus will generally affect both eyes, although the severity can differ in each eye. The symptoms will usually become noticeable in those in their teens and early twenties. The symptoms often change as the person ages.
Early symptoms may include:
- blurry vision
- distortion of vision
- increase in light sensitivity
- mild irritation
- glare in the eye
The rate of progression of keratoconus varies with each person. Often, keratoconus progresses slowly for 10 to 20 years and will then suddenly stop.
As it progresses, more common symptoms include:
- increased nearsightedness or astigmatism
- increased blurriness and distortion of vision
- needing frequent eyeglass prescription changes
Sometimes, the condition will progress rapidly, leaving those affected by keratoconus with scarring of the cornea. This causes the cornea to become less smooth and clear. As a result of the scar tissue, even more blurring and distortion of vision can occur.
Treatment of keratoconus depends on the individual, and the severity/progression of the condition. In the early stages, vision can be corrected by eyeglasses. But as the condition becomes worse, rigid contacts can be necessary to ensure that light entering the eye is refracted evenly. A person with keratoconus should not rub their eyes, as this causes the thin corneal tissue to become even more irritated.
Those affected by keratoconus are not candidates for LASIK and PRK. These procedures should never be performed on those with this condition, and doing so will make a thin and unstable cornea even worse.
A corneal transplant is recommended when non-surgical treatments no longer improve vision. This surgery is only needed by 10-20% of patients. During the procedure, the surgeon will remove the diseased cornea from the eye and replace it with a donor cornea. Corneal transplant will relieve some of the symptoms of keratoconus, but it may not provide you with perfect vision. Sometimes, eyeglasses and contacts are still necessary.