Keratoconus is progressive thinning of the cornea and the most common corneal disorder in the US, affecting one in every 2,000 Americans. It is more prevalent in teenagers and adults in their 20s.
Keratoconus arises when the middle of the cornea thins and gradually bulges outward, forming a rounded cone shape. This abnormal shape changes the cornea’s ability to refract light and can cause severe distortion and blurriness. Sometimes keratoconus is so severe it can cause corneal swelling and scarring that can severely impair vision.
Keratoconus can be inherited, but can also be caused by excessive eye rubbing. It is more common in groups of people who rub their eye frequently including patients with allergies and systemic diseases such as Lebers congenital amaurosis, Ehler-Danlos syndrome, and Down syndrome.
Keratoconus can usually be treated with glasses or special contact lenses. In about 10 to 20 percent of keratoconus patients, the corneal shape is too irregular for any kind of contact and a cornea transplant is required to improve vision. The survival rate of corneal transplant is about 90% in patients with keratoconus.
Collagen crosslinking is a new treatment for keratoconus. It uses riboflavin (Vitamin B2) and UV light to strengthen the cornea. It is like putting steel rebar in concrete to strengthen the wall of a building. With this new treatment, some keratoconus patients may stop having progressive corneal thinning.