Material and Methods: After the full ophthalmologic examination of healthy volunteers, CCT measurements were taken with LenStar LS900, Topcon SA-1P and ultrasound pachymetry in the same session. The correlation of measurements with each other were evaluated with paired samples t-test and Bland-Altman graphs.

Results: Thirty six percent of 71 volunteers were female and 35% were male and the average age was 35.4±8,3 years. The mean spherical equivalent was d etected as -1.15±0.67 D. The mean CCT values measured by LenStar, Topcon SA-1P and ultrasonic pachymetry were 533,4±35.8 ?m, 542,9±36,6 ?m, 532,4±36,2 ?m, respectively. CCT measured with Topcon SA-1P was signifi cantly higher than the other two methods (p<0.001,in both cases). Also, there was no correlation between the measurements of Topcon CT1-P and other two devices. (LenStar; R=0,023 p=0,456, ultrasonic pachymetry; R=-0.010 p=0,762). The measurements obtained with LenStar and ultrasonic pachymetry were pretty close to each other (p:0,875). And there was a correlation between the measurements of the two devices (R=0.600, p=0.001).

Conclusion: The mean CCT measured by Topcon SA-1P was approximately 10 ?m higher than with both ultrasound pachymetry and LenStar. Hence, the corrected IOP presented by the device might be approximately 1 mm Hg lower than the true IOP. This condition can be important for glaucoma screening and especially in follow-up of patients with advanced stage glaucoma. Keywords : Central Corneal Thickness, Ultrasonic pachymetry, Optical low-coherence reflectometry