Posters

Comparing intraocular lens power prediction post keratorefractive myopic surgery using the True K vs various formulas/methods

Poster Details

First Author: A.Abulafia ISRAEL

Co Author(s):    W. Hill   D. Koch   L. Wang   G. Barrett           

Abstract Details

Purpose:

To evaluate the accuracy of methods of intraocular lens (IOL) power prediction after previous laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) comparing the Barrett True K formula with various formulas/methods available on the American Society of Cataract and Refractive Surgery IOL power calculator.

Setting:

Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, and private practice, Mesa, Arizona, USA

Methods:

The following methods/formulas were evaluated and compared to the Barrett True-K formula: Adjusted Atlas, Masket, Modified-Masket, Wang-Koch-Maloney, Shammas and the Haigis-L. A separate analysis was made to evaluate and compare the True-K to the Shammas and the Haigis-L formulas in eyes without any data regarding the surgically induced change in refraction (ΔMR).

Results:

Overall, 88 eyes were available for analysis. The Barrett True-K had a significantly smaller median absolute refraction prediction error as compared to all other formulas (except for Masket), a significantly smaller variances compared to Wang-Koch-Maloney, Shammas and the Haigis-L formulas and a greater percentage of eyes within ±0.50 D and ± 1.0 D of refractive prediction errors. When ΔMR was not used, the True K had a significantly smaller median absolute refraction prediction errors and a greater percentage of eyes within ±0.50 D and ± 1.0 D of refractive prediction errors as compared to the Shammas and the Haigis-L formulas.

Conclusions:

The Barrett True-K formula gave better or similar results as compared to various methods and formulas from the ASCRS online calculator.

Financial Disclosure:

NONE