Título

COMPARISON OF THE GALILEI G4 SCHEIMPFLUG SYSTEM AND THE ITRACE ABERROMETER FOR THE MEASUREMENT OF ANTERIOR SEGMENT PARAMETERS IN CATARACT PATIENTS

Objetivo

To compare anterior segment parameters obtained by the Galilei G4 Scheimplflug system (Ziemer Ophthalmics, Switzerland) and the iTrace aberrometer (Tracey Technologies, TX, USA) in cataract patients.

Método

Preoperative and postoperative best corrected visual acuity (BCVA), spherical equivalent, cornea spherical aberration, angle kappa, keratometry readings in the flat (Kf) and steep (Ks) meridians were measured with the Galilei and iTrace systems in 49 eyes of 37 cataract patients. Statistical evaluation was performed using the paired t test, Pearson correlation, and Bland-Altman analysis for comparison of measurement techniques.

Resultado

The average of differences with confidence interval estimated by Hodges-Lehman and Wilcoxon test between Galilei and iTrace measurements were: for Flat SimK, the mean of differences was 0.137, (p = 0.149). For Flat SimK axis, mean of differences was - 4.11, (p = 0.599). For Steep SimK, the mean of differences was 0.202, (p = 0.060). For Steep SimK axis, the mean of differences was 11.2, (p = 0.070). For SimK, mean of differences was 0.169, (p = 0.028). For spherical aberration, the mean of differences was 0.107, (p = 0.261). For angle kappa, the mean of differences was 0.078, (p = 0.001). The Spearman correlation coefficient between devices were: for Flat SimK, Ro Spearman was 0.939, (p < 0.001). For Flat SimK axis, Ro Spearman was -0.641, (p < 0.001). For Steep SimK, Ro Spearman was 0.9677, (p < 0.001). For Steep SimK axis, Ro Spearman was 0.748, (p < 0.001). For SimK, Ro Spearman was 0.961, (p < 0.001). For Spherical aberration, Ro Spearman was 0.540, (p < 0.001). For angle kappa, Ro Spearman was 0.745, (p < 0.001). The total ocular aberration obtained with iTrace, in the preoperative was 0.454 (±1.44) and in postoperative, it was 0.109 (±0.08), (p =0.038).

Conclusão

Our study suggests that Galilei and iTrace have good concordance in measurement of some parameters of the anterior segment of the eye, such as keratometry and axis, but they are not interchangeable in relation to measurement of angle kappa and spherical aberration.