Repeatability and agreement of five imaging systems for measuring anterior segment parameters in healthy eyes

• DOI: 10.4103/ijo.ijo_729_16
• Publication Date: 2017-05-17T06:19:28Z
• Authors: Mukesh Kumar; Rohit Shetty; Chaitra Jayadev; HarshaL Rao; Debarun Dutta
• Keywords: Sirius; Repeatability; Coefficient of variation

Purpose: The purpose of this study is to assess the repeatability and agreement five imaging devices, namely, Pentacam (Oculus), Sirius (CSO), Orbscan IIz (Bausch Lomb), Corvis ultrasound pachymetry (UP, Tomey) in measuring steep keratometry (sKm), flat (fKm), central corneal thickness (CCT), thinnest (TCT), anterior chamber depth (ACD) healthy individuals. Design: This was prospective, comparative study. Subjects: Forty-six Indian patients. Materials Methods: eyes 46 participants underwent three consecutive scans on each device by a single examiner. Within-subject standard deviation, test–retest (TRT), coefficient variation (COV) for assessing Bland–Altman plots between mean measurements machine were analyzed. Main Outcome Measures: devices sKm, fKm, CCT, TCT, ACD. Results: TRT sKm ranged 0.23 diopter (D) (with Pentacam) 0.83 D Orbscan). same ACD, CCT 0.28 0.74 Sirius), 7.78 μm (Sirius) 19.81 (Orbscan), 0.05 mm (Orbscan) 0.07 (Sirius), 7.36 18.02 respectively. fKm with significantly lower than those Sirius. TCT measurement that (4.53 μm) (7.15 μm). There statistically significant differences all parameters devices. 95% limit analysis wide pairs Significant proportional bias detected ACD Pentacam. Conclusions: estimates Pentacam, Orbscan, Sirius, Corvis, UP good. However, cannot be used interchangeably segments measurements.