Posters

Effect of Haigis-T formula of a swept-source optical biometer on prediction of corneal astigmatism correction with toric intraocular lenses

Poster Details

First Author: H.Lee SOUTH KOREA

Co Author(s):    M. Kim   W. Wee                 

Abstract Details

Purpose:

Haigis-T formula (H-T) of a Swept-Source Optical Biometer (IOLMaster�Â�® 700) has been newly provided to calculate toric intraocular lens (IOL) power and astigmatism. We compared the accuracy of H-T with that of Z Calc provided from Zeiss toric calculator for predicting corneal astigmatism correction with a toric IOL.

Setting:

Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea Laboratory of Ocular Regenerative Medicine and Immunology, Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute, Seoul, Korea

Methods:

Medical records of 17 eyes from 15 patients who underwent uneventful cataract surgery with toric IOL (AT TORBI 709M�Â�®) implantation were retrospectively reviewed. The mean preoperative corneal astigmatism was 2.06 D. The magnitude of error (ME) defined as the difference between surgically induced astigmatism vector (SIA) and target induced astigmatism vector (TIA) predicted by H-T and Z Calc was compared. The absolute magnitudes of error, predicted refractive errors and absolute errors calculated by the 2 calculators were also compared.

Results:

The mean postoperative SIA was 2.412 D. The ME predicted by H-T and Z Calc was 0.157 D and 0.171 D, respectively, with a significant difference (p = 0.028, Wilcoxon signed rank test). The absolute magnitude of error, predictive refractive error and absolute predictive refractive error were not significantly different between H-T and Z Calc.

Conclusions:

The magnitude of astigmatic correction predicted by H-T of IOLMaster�Â�® 700 seems to be underestimated compared to that of Z Calc from Zeiss toric calculator. The accuracy of the calculation from H-T for spherical equivalent of IOL seems to be comparable to that from Zeiss toric calculator.

Financial Disclosure:

NONE