Assesment of Central Corneal Thickness Using Corneal Dynamic Scheimpflug Analyzer Corvis ST, Sirius Kombine Scheimpflug-Placido Disk System and RTVue Anterior Segment Optical Coherence Tomography in Normal Eyes

Abstract

INTRODUCTION: To examine the repeatability of central corneal thickness (CCT) measurements by corneal dynamic Scheimpflug analyzer Corvis ST (Corvis), RTVue anterior segment optical coherence tomography (OCT) and Sirius corneal topography (Sirius) in normal eyes and compare the agreement of devices with each other. METHODS: Forthy right eyes of 40 patients were included in the study. Patients with active ocular pathology and a history of ocular trauma were excluded. All measurements were performed from 12: 00 to 15: 00 by the same physician. RESULTS: The mean age of the subjects was 35,5+-2,3 and 22 were males and 18 were females. Interclass correlation coefficient was 0.993 for Corvis, 0,998 for OCT and 0.990 for Sirius. CCT was 8,4u thinner in OCT compared with CORVIS and 4,0u thinner compared with Sirius. Limits of Agreement (LoA) of devices was -6,7 to 14.7u for Corvis and Sirius, -25.6u to 8.8u for Corvis and OCT, -19.9 to 13.0u for Sirius and OCT. Two devices which had the narrow LoA (which means the best agreement with each other) were Sirius and Corvis. DISCUSSION AND CONCLUSION: It has been observed that repeatibility of all three devices were very good for CCT measurement. Agreement of Sirius and Corvis was better when compared with other devices. Thus, Corvis and Sirius can be alternatively used in clinical practice. Since measurements performed by OCT were thinner than other devices, OCT can be used in clinical practice when minor changes are critical in CCT measurement.

Keywords

• central corneal thickness
• anterior optical coherence tomography
• corneal topography
• corneal dynamic scheimpflug analyzer corvis st.