Eye Disorders: Keratoconus
Keratoconus is a rare condition of the cornea, occurring in perhaps 1 out of 5000 people. The cornea is normally a clear round dome which we see through on the front of the eye. In keratoconus, the corneal tissue becomes thin and weak, developing a cone-like bulge. The cause of keratoconus is not completely understood. There is probably a genetic component (there are families with keratoconus), as well as an environmental component (seen more commonly in allergic eye conditions and in people who rub their eyes a lot).
What are the symptoms of keratoconus?
The cornea is a very important refractive surface of the eye, meaning that it plays a large role in focusing light on the retina. A smooth and regular corneal surface is required for clear vision. The cornea becomes irregular and sometimes scarred in keratoconus, causing blurry vision and glare. Early in the disease process, symptoms may be very mild. Later, increasing astigmatism and myopia occur, leading to contact lens and glasses changes. Sometimes light sensitivity and eye irritation occur. Rarely in advanced situations, the cornea may suddenly swell (called hydrops), leading to a sudden drop in vision and discomfort.
How is keratoconus treated?
Rigid Gas Permeable contact lenses are often helpful to restore useful vision when glasses cannot help. It is not currently known (2010) whether contact lenses slow the progression of keratoconus, but that question is being investigated by the National Institutes of Health. When glasses and contacts are not helpful, a corneal transplant can be considered. Most people will not progress far enough to need a corneal transplant. All "eye rubbing" behavior should stop.
More information on this condition can be found at the National Eye Institute's website, under the corneal section.