Comparison of central corneal thickness using anterior segment optical coherence tomography, ultrasound pachymetry, and orbscan

Background The thickness of the cornea is a sensitive and important indicator for the health of the cornea. It is beneficial for evaluating endothelial pump function and corneal barrier, monitoring the disorders of the cornea such as keratoconus and corneal edema, and choosing patients for refractive surgery. Aim The aim of this work was to compare central corneal thickness (CCT) using orbscan, ultrasound pachymetry (USP), and anterior segment optical coherence tomography (AS-OCT). Patients and methods This prospective study was carried out on 60 eyes of 30 individuals aged from 18 to 40 years old and with clinically normal cornea who attended the outpatient clinic of Tanta University Hospital and Nour El Ein Hospital from April 2018 till March 2019. Results There was no statistically significant difference in mean minimal measurement of the thickness of the central cornea as measured by the three devices. There was a statistically significant difference in the mean maximal measurement of the CCT as detected by the three devices. The average CCT was statistically significantly different across the three devices. Conclusions OCT, USP, and orbscan were reliable for CCT measurement. Orbscan and USP were more reproducible, but OCT and ultrasound were more technically dependent. The average CCT was the highest by orbscan.