Corneal topography plays an important role in laser in situ keratomileusis (LASIK). Preoperative screening permits the detection of keratoconus and other corneal shape anomalies that may be a contraindication for refractive surgery. Monitoring the progress of the surgical outcome with topography is helpful to detect postoperative complications such as decentration and clinically significant irregular astigmatism. LASIK compares favorably with PRK for the treatment of low to moderate myopia in terms of early achievement of refractive stability, but induction of modest amounts of irregular astigmatism can be a concern.