In Reply Although the article by Ladas et al1 focuses on the Holladay 1, Hoffer Q, SRK/T, and Haigis formulas, my commentary does acknowledge the more modern Olsen, Barrett, and Holladay 2 formulas in paragraph 8 and in references 6 and 7.
Ultimately, I believe that even more sophisticated approaches incorporating additional measurements such as anterior corneal curvature, posterior corneal curvature, corneal thickness, or wavefront analysis will become more prevalent as advanced diagnostic imaging instruments become routinely used. Formulas replacing simple traditional keratometry with more detailed anterior segment assessment via optical coherence tomography,2 Scheimpflug imaging,3 or ray tracing analysis4 have already been described.