Comparison of ultrasonic pachymetry, with a new optical biometry and tono-pachymetry

Abstract
The aim of this study was to compare the measurements of central corneal thickness (CCT) using the CT-1P tonopachymetry and AL-Scan optical biometry with those obtained with ultrasound (US) pachymetry. In this prospective study, CCTs were measured in 100 eyes of healthy subjects with the CT-1P tonopachymetry, AL-Scan optical biometry and US pachymetry, and the results were compared. The mean CCT taken with the CT-1P, AL-Scan optical biometry and US pachymetry were 514.1±34.96 µm, 540.00±29.57 µm and 542.53±31.2 µm, respectively. There were high correlations between CCT readings using US pachymetry and AL-Scan optical biometry (r=0.949, p= 0.001), between US pachymetry and CT-1P tonopachymetry (r=0.851, p< 0.001) and between AL-Scan optical biometry and CT-1P tonopachymetry (r=0.859, p< 0.001). Both AL-Scan optical biometry and CT-1P tonopachymetry are quick, non-contact devices that are easy to use and are reliable alternatives to US pachymetry for measuring CCTs.