Calculating equivalent K readings.

摘要

I congratulate Symes and Ursell1 on their well-designed, well-executed study and their excellent discussion comparing automated keratometry (K) and Scheimpflug in the preoperative assessment of cataract patients. In their study, they confirmed almost exactly the results we found in the original article on equivalent K readings over a 4.5 mm zone,2 with a difference of only -0.018 diopter (D), a 95.3% r value, and a standard deviation of 0.47 D (ours was 0.56 D for the laser in situ keratomileusis [LASIK] patients). I would like to comment on 2 points raised in the article.