Comparison Of Corneal Higher-Order Aberrations Measured With A Pentacam Hr Scheimpflug Camera And A I-Trace Ray-Tracing Aberrometer

Published 2022 - 40th Congress of the ESCRS

Reference: PP03.05 | Type: ESCRS 2022 - Posters | DOI: 10.82333/8eg1-by32

Authors: Chan-Ho Cho* ¹ , Do Hee Jung ¹ , Kang Yeun Pak ¹

¹Ophthalmology,Inje University College of Medicine, Haeundae Paik Hospital,Busan,Korea, Republic Of

Purpose

The purpose of this study was to compare the measured difference in high-order corneal aberrations between the Pentacam HR based on the Scheimpflug principle and the ocular aberrometer i-Trace based on the ray-tracing principle.

Setting

Retrospective, consecutive study

Methods

Total 84 eyes of 69 patients were enrolled in this study, who had no ocular surgery history from January to December 2021 and had both Pentacam HR and i-Trace devices measured on the same day. Higher corneal aberrations (HOAs) were analyzed using the root mean square (RMS) values of the Zernike 3rd and 4th terms in the area 4 mm from the center of the cornea. Paired t-test was used to measure the average difference between the two instruments, and the correlation was analyzed by Pearson correlation coefficient. The agreement between the two instruments was analyzed using the Bland-Altman plot.

Results

There were no significant differences in total HOA (0.231 vs. 0.215 um, p=0.440), coma (0.125 vs. 0.133, p=0.581), and spherical aberration (0.051 vs. 0.033, p=0.181) between the i-Trace and Pentacam. There was a significant difference in trefoil (0.125 vs. 0.088 um, p=0.006) between the i-Trace and Pentacam. In correlation analysis, total HOAs (r=0.464, p<0.001), coma (r=0.705, p<0.001), and spherical aberration (r=0.235, p=0.032) showed a significant correlation between the two instrument measurements. Trefoil or secondary astigmatism showed no significant correlation between the two instruments. The Bland-Altman plot showed low agreement between the two instruments in all high order aberration items.

Conclusions

The total corneal HOA, corneal coma and corneal spherical aberration measured by Pentacam HR and i-Trace showed a significant correlation, and there was no significant difference in the measured values between the two devices. However, in the remaining high-order aberration items, the correlation between the two instruments was low and the overall degree of agreement was low, so the complementary interpretation of the measurements between the two instruments is thought to be limited.