Comparison between central corneal thickness measurements by oculus pentacam and ultrasonic pachymetry

Abstract

Purpose: To compare the accuracy of central corneal thickness (CCT) measurements by the oculus pentacam scheimpflug system, with those obtained with the DGH ultrasound pachymeter (UP) and to assess the agreement between the two devices.

Methods: In a prospective study, measurement agreement was assessed in 984 eyes of 492 healthy subjects using both oculus pentacam and ultrasonic pachymetry at the Eye Consultants Center, Riyadh, Saudi Arabia.

Result: In the measurement agreement experiment, the mean CCT was 552.4 +/- 37.0 microm with oculus pentacam and 544.1 +/- 35.4 microm with ultrasonic pachymetry. Regression analysis showed a high correlation between the values obtained with both devices (r = 0.912, P < 0.001). Compared with UP, pentacam overestimated the CCT by a mean of 8.2 microm as demonstrated in a Bland-Altman plot.

Conclusion: the CCT measurements by the pentacam and UP are highly correlated. The pentacam agrees well with UP and is a reliable alternative to UP in CCT measurements.