Posters

Differences in central corneal thickness according to measurement device in patients with severe dry eye disease

Poster Details

First Author: A.Celebi TURKEY

Co Author(s):    G. Mirza              

Abstract Details

Purpose:

It was aimed to compare central corneal thickness (CCT) measurement via Spectral Domain- Optical Coherence Tomography (SD-OCT) and ultrasonic pachymetry in patients with dry eye disease (DED) to determine the level of agreement between these 2 methods.

Setting:

Prospective observational study

Methods:

This study included 28 severe DED patients. CCT measurement via Cirrus SD-OCT was performed before ultrasonic pachymetry. The paired samples t-test was used to compare CCT values. Matching analysis between both methods was performed using intraclass correlation coefficient (ICC). Intrasession reliability of the measurement methods was calculated via the concordance correlation coefficient (CCC), variation equivalent, and Pearson’s correlation coefficient. The Bland-Altman procedure was used to graphically represent the differences between CCT measurements obtained via the 2 methods, as well as in the matching limits a 95% limits of agreement (LoA).

Results:

The study included 56 eyes of 24 female and 4 male patients. Mean age of the patients was 50.9±11.3years (range: 26-68 years). Mean CCT via Cirrus SD-OCT was 523.82±30.98µm, versus 530.050±31.85µm via ultrasonic pachymetry; the mean difference between the 2 methods’ measurements was significant (6.23µm)(paired samples t-test,P<0.001). The Bland-Altman plot showed good agreement between the examiners; LoA width was 14.8µm. The ICC for repeatability was 0.974 (95%CI:0.955-0.984). The CCC between the 2 methods’ CCT measurements was 0.973 (95%CI:0.958-0.983). The variation equivalent was 0.976 and Pearson’s correlation coefficient was 99.3%, which also indicated high correlation between the 2 methods’ measurements.

Conclusions:

The present findings show that in patients with DED Cirrus SD-OCT provides reliable intraobserver CCT measurements and consistent agreement between independently trained observers. However, the difference in CCT based on SD-OCT and ultrasonic pachymetry measurement should always be a consideration when interpreting CCT values in DED patients. FINANCIAL DISCLOUSRE: NONE