Keratoconus is an eye condition in which there is a gradual deterioration of the structure of the cornea, causing it to thin and bulge out. Usually discovered during adolescence, this degenerative disorder of the eye causes decreased visual acuity (sharpness) and distortion of images. Keratoconus affects one person in a thousand. This condition is not associated with redness, inflammation or other acute symptoms and therefore may go undetected for years.
Although it occurs in populations throughout the world, it seems to occur more frequently in certain ethnic groups such as South Asians. The exact cause of keratoconus is uncertain, but it has been associated with detrimental enzyme activity within the cornea. A number of sources suggest that keratoconus likely arises from a number of different factors: genetic, environmental or cellular, any of which may form the trigger for the onset of the disease.
In early stages of keratoconus, spectacles or soft contact lenses can suffice to correct for the mild astigmatism. As the condition progresses, these may no longer provide the patient with a satisfactory degree of visual acuity, and most clinical practitioners will move to managing the condition with rigid contact lenses. When thinning of the cornea becomes excessive, or scarring, as a result of contact lens wear, a corneal transplantation or penetrating keratoplasty becomes required.