Keratoconus.

Keratoconus is a slowly progressive, non-inflammatory disorder of the eye characterized by thinning and protrusion of the cornea. Typically diagnosed in the patient's adolescent years, keratoconus may lead to substantial distortion of vision primarily from irregular astigmatism and myopia, and secondarily from corneal scarring. The classic histopathologic features include breaks in Bowman's layer and thinning of the corneal stroma. The etiology of keratoconus remains unclear. Form fruste keratoconus shows little progression, and has become known due to videotopographic analysis; it is very important to rule out in refractive surgery candidates. Treatment begins first and foremost with contact lenses, progressing to surgery as contact lens intolerance develops, with the goal of stabilization, including: cross-linking, intrastromal corneal ring segments and corneal transplantation.