Purpose: To compare central corneal thickness (CCT) measured by Galilei and Orbscan II with that by ultrasonic (UIS) pachymetry in unoperated eyes.
Methods: CCT was measured in 184 unoperated eyes of 92 healthy retractive surgery candidates using Galilei, Orbscan II, and U/S pachymetry. Considered as a benchmark, measurements by U /S pachymetry were compared to those obtained by the other two devices. Agreement between the three instruments was assessed using regression analysis, mountain plots, and Bland-Altman plots.
Results: Mean CCT was 544.4±33.4 mm, 546.7±37.9 mm, and 555.8±29.6 mm, as measured by ultrasonic pachymetry, Orbscan II, and Galilei systems, respectively. Mean differences between readings measured by U /S pachymetry and those measured by Orbscan II (acoustic coefficient 0.96) and Galilei were 2.3 mm and 10.2 mm, respectively. Despite this discrepancy, Galilei had a better agreement with U /S pachymetry as compared to Orbscan II (correlation coefficient of 0.947 vs 0.817). Considering acoustic coefficient of 0.98 for Galilei, its CCT readings were more similar to U /S pachymetry.
Conclusion: Galilei is well correlated with U/S pachymetry for measurement of CCT in normal eyes and by applying an acoustic coefficient of 0.98 for Galilei, its records can be considered equivalent to U/S pachymetry. Further investigations are required to address its accuracy in abnormally thin corneas such as corneal ectasia and after refractive surgeries.