Holladay 2 vs 1

The Holladay 2 formula is a 7-variable predictor of Effective Lens Position (ELP) using AL, K, ACD, LT, WTW, AGE and Adult Refraction before affected by the Cataract. There are at least 25 articles now that show the improved efficacy since we introduced the formula in 1995. The more you know about the anatomy of the eye, the better you can predict the ELP.

In the last year (2017) we also introduced the Holladay Nonlinear Regression in Long Eyes to improve the accuracy. All Formulas make hyperopic errors in LONG EYES and WANG/KOCH were the first to recognize this and had regression formulas for the H1 only.

Today, using the H2 and the Nonlinear Regression in LONG EYES will give the best results.