Posters

Refraction after cataract surgery depending on intraocular lens calculation formula

Poster Details

First Author: Ē. Elksnis LATVIA

Co Author(s):    D. Raščevskis   G. Laganovska                 

Abstract Details

Purpose:

Prospective study was made to evaluate and compare predictability and accuracy of three IOL power calculation formulas (SRK/T, SRK II and Haigis) for IOL power calculation. The postoperative refractive expectations of patients having cataract surgery have been increased due to the advances in technology. Therefore, accurate intraocular lens (IOL) power calculation is very important to attain the postoperative target refraction. [6] Results between each formula could not differ, but frequently there are patients with a radical difference in calculations.

Setting:

Pauls Stradins Clinical university hospital, Riga, Latvia!

Methods:

Study included 25 eyes, who underwent phacoemulsification with IOL implantation. Postoperative refraction and refraction predicted by the SRK II, SRK/T and Haigis formulas were analyzed. The mean estimation error (EE), mean absolute estimation error (AEE) and the percentage of eyes within target refraction (EWTR) (± 0.50 D and ± 1.00 D) for all three formulas were compared. Analysis was repeated in three groups with three subgroups. These groups formed based on axial length (AL)keratometry (K value) and anterior chamber depth (ACD).

Results:

In overall study group, smallest mean AEE (0.33 ± 0.17) was provided by SRK/T formula. The highest percentage of EWTR was also found by using SRK/T (80% and 100%). SRK/T provided smallest mean AEE (0.55 ± 0.25 and 0.26 ± 0.18) for groups 1.1 (n = 8) and 1.3 (n = 7), however, there was no statistically significant difference between all formulas in group 1.3 (P = 0.22). In group 1.2 (n = 10), smallest mean AEE (0.37 ± 0.26) was obtained using SRK II. Haigis provided smallest mean AEE (0.31 ± 0.09) in group 2.1. In both, group 2.2 and 2.3 the smallest mean AEE was found by using SRK/T (0.43 ± 0.18) and 0.21 ± 0.09).

Conclusions:

Better results can be obtained using SRK/T formula in almost every eye, except SRK II formula may be preferred in eyes with moderate AL and Haigis formula in eyes with K value under 43D.

Financial Disclosure:

NONE