Keratoconus is a degeneration of the cornea (first lens of the eye) which becomes thin, bends and deforms preventing it from a correct performance and leading to a significant vison distortion due to the irregular astigmatism it causes. It normally starts at an early age, in adolescence, and may progress up to 30-35 years of age. Usually, a keratoconus present in an adult older than 40, doesn’t move forward and remains stable.

This pathology’s aetiology is multifactorial. In some cases, there exists a genetic predisposition whereas in other ones it appears without having any relation with heredity. The most important risk factor to favour the appearance of a keratoconus is eye rubbing. Children or teenagers who stroke their eyes frequently and strongly must be taught to stop doing so and ought to be taken to the ophthalmologist’s in order to discover and treat the underlaying reason of their itching. In other cases, the keratoconus is related to general pathologies such as atopic dermatitis, Marfan syndrome, Down syndrome, etc.

There exist different severity stages. From the asymptomatic one to a sudden vision loss. The most usual one, is a progressive visual acuity diminishment over time and in relation to the cornea’s deformation advance, the result of corneal astigmatism increase.

According to the severity of each case there exist different treatments: · Glasses or gas permeable rigid contact lenses for initial or stable cases. · Collagen reticulation by means of UVA rays or cross-linking to try to stop the keratoconus advance. · Intracorneal rings to try to modify the cornea’s shape and reduce astigmatism. · In truly severe cases, the only possible solution is corneal transplantation which may be lamellar or complete (penetrating ketaroplasty).