Posters

Astigmatism evaluation in patients with toric intraocular lens

Poster Details

First Author: A.Lencova CZECH REPUBLIC

Co Author(s):    L. Filipova   Z. Hlinomazova           

Abstract Details

Purpose:

The aim of our study was to evaluate the preoperative and postoperative values of corneal astigmatism measured by three different devices (IOL Master, Pentacam, and topographer) in patients after refractive lens exchange with implantation of intraocular monofocal toric lens and to analyse the refractive outcome.

Setting:

European Eye Clinic Lexum, Prague, Czech Republic

Methods:

Our study comprised 20 eyes of 11 patients who underwent an uneventful clear lens extraction with implantation of a toric monofocal lens with plate haptic (AT TORBI 709M, Carl Zeiss Meditec) between 2011 and 2013 for a correction of hyperopia with astigmatism (19) and mixed astigmatism (1). The mean patient age was 54 years (range 46 to 67 years). Keratometry readings were obtained with optical biometry (IOL Master), Pentacam, and a topographer. The astigmatism of posterior ocular surface was measured by Pentacam. We evaluated the correlation of final objective and subjective refraction with the amount and axis of astigmatism measured with different types of devices. Keratometry values based on IOL Master were used for IOL calculations. The mean follow-up was 1 year.

Results:

The preoperative keratometry measured with optical biometry was 42.21 ±2.10 D (K1) and 45.12 ±2.75 D (K2), with Pentacam 42.33 ±1.79 D (K1) and 44.97 ±2.55 D (K2), and with topographer 41.77 ±1.94 D (K1) and 44.74 ±2.33 D (K2). The mean preoperative astigmatism was 2.90 ±1.61 D based on IOL Master and 2.96 ± 1.56 D based on topographer. The astigmatism measured by Pentacam (based on anterior corneal surface) was significantly lower than values from IOL Master and topographer (p˂0.05), with the mean value of 2.65 ±1.48 D. The mean postoperative amount of astigmatism was 3.01 ±1.60 D based on IOL Master, 3.06 ±1.54 D based on topographer and 2.73 ±1.49 D based on Pentacam. The mean preoperative value of astigmatism of posterior corneal surface was 0.67 ±0.32 D, while postoperative values were 0.63 ±0.24 D. Decimal uncorrected distance visual acuity increased from the mean preoperative value of 0.18 ±0.16 to 0.75 ±0.20 one year after the surgery. The mean spherical equivalent changed from +4.86 ±2.91 D to -0.03 ±0.52 D. The subjective astigmatism 1 year after the surgery was 0.58 ±0.55 D.

Conclusions:

The keratometry values based on IOL Master measurements are suitable for toric lens calculation and allow to obtain an accurate refractive outcome. When keratometry values obtained with Pentacam are used, there is a risk of residual postoperative astigmatism. FINANCIAL INTEREST: NONE