Accuracy of a novel ultrasound biomicroscope for measuring corneal epithelial thickness and agreement with an SD-OCT based device.

Publication date: Oct 09, 2025

To assess the accuracy of corneal epithelial thickness (ET) measurements in healthy and post transepithelial photorefractive keratectomy (post-T-PRK) eyes using a novel ultrasound biomicroscope (Insight 100, ArcScan, Colorado, USA) and to compare the agreement with the measurements provided by a spectral-domain optical coherence tomographer (RTVue-XR, Optovue, Fremont, CA). In total, 32 healthy and 38 post-T-PRK eyes were included. Three consecutive measurements of right eye were acquired with the Insight 100 VHF-UBM and RTVue-XR SD-OCT. Accuracy was analyzed using intraclass correlation coefficient (ICC), test-retest repeatability (TRT), within-subject coefficient of variation (CoV), and within-subject standard deviation (S). Agreement was assessed by Bland-Altman analysis and paired t-tests. The precision of the normal eyes were higher than post-T-PRK eyes. Central epithelial thickness (CET) had the best repeatability and reproducibility, CoV was 0. 5%∼1. 71%. The S and TRT was 0. 35um and 0. 79um in normal eyes, 1. 02um and 1. 92um in post-T-PRK eyes. ET has poor repeatability in normal eyes. However, post-T-PRK eyes have the worst repeatability at ET and ET . Agreement of CET was excellent in both groups. The widest 95% LoA range appeared at ET of normal and post-T-PRK eyes, with 0. 72∼8. 74um and -9. 51∼7. 32um, respectively. The Insight 100 provides good repeatability and reproducibility for ET measurements in normal and post-T-PRK eyes. CET can be used interchangeably between Insight 100 and RTVue-XR, however, it is not recommended for other positions.

Semantics

Original Article