Intra-examiner repeatability and agreement of central corneal thickness measurements by four different optical devices and an ultrasound pachymeter

Session Details

Session Title: Cornea
Session Date/Time: Friday 10/02/2017 | 08:30-10:00
Paper Time: 09:24
Venue: Brussels Room 0.4

First Author: N.Buyuktortop Gokcinar TURKEY
Co Author(s): N. Ornek  E. Yumusak  S. Yorubulut  Z. Onaran        

Abstract Details

Purpose:

To compare the repeatibility and agreement of central corneal thickness (CCT) measurements by spectral domain optical coherence tomography (OCT), combined Scheimpflug placido system corneal topography (CT), optical biometry (OB), specular microscopy (SM) and ultrasound pachymeter. (UP).

Setting:

K?r?kkale University, School of Medicine, Department of Ophthalmology and K?r?kkale University Department of Statistics

Methods:

Central corneal thickness in 122 eyes of 61 subjects was measured two times by a single observer using four different optical devices, namely: Nidek RS-3000 Advance OCT, CSO Sirius combined Scheimpflug placido disc system CT, Nidek AL-Scan partial coherence interferometry based OB, Tomey EM-3000 SM and Reichert iPac ultrasonic pachymeter . Corrected pachymetry values in the software of SM device were also recorded. The agreement between devices were evaluated by Bland-Altman plots and 95% limits of agreement. The correlation of CCT values were analyzed with Pearson correlation test. Intra-examiner repeatibility for each device was analyzed with intraclass correlation coefficient.

Results:

The mean CCT by OCT, CT, OB, SM, corrected SM and UP were 545.16 ﾱ 29.85, 537.68 ﾱ 32.39, 532.47 ﾱ 28.22, 527.59 ﾱ 32.76, 540.47 ﾱ 32.78 and 545.21 ﾱ 31.51 ﾵm, respectively. There were statistically significant correlations among all devices (p<0,01). There was no statistically significant difference in the mean CCT between OCT and UP; and between CT and corrected SM. But, there were statistically significant differences in the mean CCT among the other devices (p<0.05). The mean paired differences between devices were ranging between 0.058 ﾵm and 17.621 ﾵm. Intra-examiner repeatibility was excellent in all devices (>0.96).

Conclusions:

Quite different results may be obtained with different techniques of CCT measurement. Therefore, it would be better to choose the same or the most compatible devices for CCT evaluation and follow-up.

Financial Disclosure:

None