TFOS DEWS II Report Executive Summary

This article presents an Executive Summary of the conclusions and recommendations of the 10-chapter TFOS DEWS II report. The entire TFOS DEWS II report was published in the July 2017 issue of The Ocular Surface. A downloadable version of the document and additional material, including videos of diagnostic and management techniques, are available on the TFOS website: www.TearFilm.org

Determination of the corneal asphericity after myopia surgery with the excimer laser: A mathematical model

PURPOSE. To determine the theoretical change of corneal asphericity within the zone of laser ablation after a conventional myopia treatment, which conforms to Munnerlyn’s paraxial formula and in which the initial corneal asphericity is not taken into consideration. METHODS. The preoperative corneal shape in cross section was modeled as a conic section of apical radius R1 and shape factor p1. A myopia treatment was simulated, and the equation of the postoperative corneal section within the optical zone was calculated by subtracting the ablation profile conforming to a general equation published by Munnerlyn et al. The apical radius of curvature r2 of the postoperative profile was calculated analytically. The postoperative corneal shape was fitted by a conic section, with an apical radius equal to r2 and a shape factor p2 equal to the value that induced the lowest sum o