Corneal topography in preoperative evaluation for laser keratorefractive surgery - a review.

Corneal topography is a mandatory investigation in the preoperative evaluation of the patient candidate for laser keratorefractive surgery, in order to assess the corneal shape, to determine the radii of curvature and the corneal thickness. Abnormal corneal topography is the most important identifiable risk factor for corneal ectasia. This paper reviews the principles of successive generations of topographers and illustrates several normal and abnormal corneal topographies.