Keratoconus is an uncommon condition in which the dome-shaped cornea (the clear front dome of the eye) becomes thin and develops a cone-like bulge. As the condition progresses, the shape of the cornea is distorted, blurring your vision. Usually, keratoconus affects both eyes, although symptoms and progression in each eye may differ.
Early symptoms include mild blurring vision, increased sensitivity to light and glare, and mild eye irritation. The rate of progression varies. Keratoconus usually begins in the teenage years. It may progress slowly for 10 to 20 years. As it progresses, the most common symptoms are increased blurring, increased nearsightedness or astigmatism, inability to wear contact lenses, and frequent eyeglass prescription changes.
The causes of keratoconus are not known. Since an estimated 10% of people with keratoconus have a family member with the condition, some researchers believe genetics may play a role.
Mild keratoconus is often corrected with eyeglasses. However, as the condition progresses, rigid contact lenses are usually needed. Often, lenses specialized for keratoconus are best. If vision cannot be corrected with contact lenses, a corneal transplant may be recommended. Nonetheless, corneal transplants offer the best prognosis for clear vision.
New techniques have recently been evaluated to treat progressive keratoconus. One technique involves placing crescent-shaped acrylic inserts in the mid-periphery of the cornea. This has been shown to be effective in some patients. Another is a procedure in which the cornea is soaked in riboflavin and then bathed in ultra-violet light. This stiffens the cornea and can prevent worsening of the disease. You may want to discuss these technologies with your eye doctor.