Optimized Nomogram Development for LASIK and PRK

Commercially available software programs can create nomograms for use in surgical planning for refractive surgery procedures that make optimal use of available data. These nomograms have been termed “Optimized Nomograms.” In the development of optimized nomograms, data sets are grouped according to treatment profiles consisting of the specific laser, surgeon, laser software version, Hertz rate, treatment zone diameter, keratome, plate thickness, and user-defined parameters. Regression analyses are performed according to models derived by using actual data sets, and may incorporate linear, nonlinear, logarithmic, scalar, and higher order analyses. Regression results are screened using relevant statistics and only those variables found to have a significant effect on outcomes are used. The data used in the regressions are filtered for outliers, and are limited by using a trailing window analysis with a 0.1 diopter (D) threshold. The variables used in specific nomograms vary among data sets, showing the need for personalization of nomograms for each surgeons and each treatment profile. Optimized nomograms have been shown to result in significant improvement in the correlation of outcomes with the planned results. Optimized nomograms can significantly improve surgical outcomes. Their use depends on consistency in technique and equipment