Measurement of central corneal thickness by different techniques

Abstract

Purpose The aim of this study was to compare the central corneal thickness (CCT) measurements by three different techniques: pentacam, noncontact specular microscopy, and ultrasound biomicroscopy (UBM) devices. Patients and methods This prospective observational cross-sectional study was performed on patients seeking medical care at the outpatient clinic of Ophthalmology Center at Mansoura University. They were consecutively recruited and selected, and measurement of CCT by pentacam, UBM, and specular microscopy was done. Thereafter, the results were compared as an evaluation study of all techniques. Results This study included 200 eyes of 100 patients. The age of the included patients in the study ranged from 20 to 50 years. The mean age was 34.56±9.94 years. The CCT ranged from 465 to 630 µm, with a mean of 532.88±34.15 µm when measured by pentacam. When measured by specular microscopy, it ranged from 456 to 601 µm, with a mean 531.92±33.64 µm, and when measured by UBM, it ranged from 463 to 602 µm, with a mean 533.97±31.10 µm, with P value of 0.824 (nonsignificant). Conclusion CCT measurements obtained by UBM tend to be thicker than those obtained by pentacam and noncontact specular microscopy, but the measurements of all three are strongly positively correlated with each other. So, any of these devices can be easily substituted by the other for the measurement of CCT.

Keywords

• corneal thickness
• pentacam
• specular microscopy
• UBM