Abstract
Purpose :
Accurate assessment of central anterior segment parameters is crucial for assessing primary angle closure and determining strategies for anterior segment surgery. Hence, we aim to evaluate the reproducibility and agreement of the new hyperparallel optical coherence tomography (Cylite Optics, Melbourne, Australia) in the measurement of central biometric parameters compared to IOL Master 700 (CarlZeiss Meditec AG, Jena, Germany) and swept-source OCT (SS-OCT, CASIA SS-1000, Tomey Corporation, Nagoya, Japan).
Methods :
Cross-sectional study. Phakic subjects >40 years, with no relevant ophthalmic history were consecutively recruited from glaucoma. Each subject underwent Cylite, IOL Master, CASIA and gonioscopy on the same day before pupillary dilation in a dark room (7.5 lux). A second Cylite scan was obtained in a consecutive subset of patients (patient number 10 to 30, N=20) by a different operator to assess intra-device reproducibility. Anterior chamber depth (ACD) was obtained by Cylite, IOL Master, and SS-OCT, while lens thickness (LT) and axial length (AL) were obtained by HP-OCT and IOL Master only. Bland-Altman analyses were performed.
Results :
77 subjects’ scans were analyzed (62 open and 15 closed angles on gonioscopy). Two HP-OCT scans did not yield AL measurements (IOL Master AL were 29.15 and 31.04 mm, respectively). There were no significant measurement differences between the two sets of HP-OCT scans for any of the central biometric parameters (test re-test agreement). Lens thickness showed a significant mean difference of 0.07 mm (95%CI 0.04 to 0.10; p <0.001) when measured by HP-OCT in comparison to IOL Master. ACD measured by CASIA showed a consistent significant mean difference of ~0.42 mm (95%CI 0.39 to 0.45; p <0.001) in comparison to both, IOL Master and Cylite.
Conclusions :
Central biometric parameters assessed by Cylite demonstrated good test-retest agreement. While ACD and AL exhibited excellent agreement, the measurement LT by Cylite may underestimate values in comparison to IOL Master. Notably, ACD, a cardinal risk factor for angle closure, as measured by CASIA, may not be regarded as interchangeable when compared to measurements obtained from IOL Master and Cylite.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.