Keratoconus is a degenerative disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than its normal gradual curve. The exact cause of keratoconus is uncertain, but has been associated with detrimental enzyme activity within the cornea. A genetic link seems likely, as the incidence rate is greater if a family member has been diagnosed.
Keratoconus can cause substantial distortion of vision, with multiple images, because of irregular astigmatism. It is typically diagnosed in the patient's adolescent years and gets worse in the twenties and thirties. The deterioration in vision can affect the patient's ability to drive a car or read normal print., in case that both eyes are afflicted. In most cases, corrective lenses are effective enough to allow the patient to continue to drive legally and likewise function normally. Further progression of the disease may require surgery including intrastromal corneal ring segments, corneal collagen cross-linking, or corneal transplantation. However, despite the disease's unpredictable course, keratoconus can often be successfully managed with little or no impairment to the patient's quality of life.