Keratoconus is a progressive corneal thinning of unknown cause in which the cornea assumes a conical shape, with progressive irregular astigmatism and deterioration of visual acuity. The normal anterior corneal surface is prolate, and it could be described as conic (flattening of the radius of curvature from the apex toward the periphery)1. In keratoconus corneas, the steepening of the central ...