Repeatability, reproducibility, agreement characteristics of 2 SD-OCT devices for anterior chamber angle measurements

Abstract

ObjectiveTo evaluate the agreement, reproducibility, and repeatability of 2 spectral domain optical coherence tomography (SD-OCT) devices in Schwalbe’s line (SL)–based anterior chamber angle parameters. MethodsThe inferior anterior chamber angle of 65 eyes from 65 participants (33 right eyes and 32 left eyes) were scanned twice with the Nidek RS 3000 Advanced SD-OCT and Cirrus SD-OCT. SL angle opening distance (SL-AOD) and SL trabecular-iris-space area (SL-TISA) were graded by masked certified graders at the Doheny Image Reading Center. ResultsThe mean SL-AOD/SL-TISA was 617.3 ± 237.9 µm/0.211 ± 0.086 mm2 for the Cirrus and 633.7 ± 219.3 µm/0.218 ± 0.080 mm2 for the Nidek RS 3000 Advanced SD-OCT. The repeatability (intraclass correlation coefficients [ICCs] >0.936) and intergrader reproducibility (ICCs >0.915) in SL-AOD and SL-TISA with Cirrus OCT were excellent. The repeatability (ICCs >0.948) and intergrader reproducibility (ICCs >0.709) in SL-AOD and SL-TISA with the Nidek RS 3000 Advanced SD-OCT were moderate to good. Moderate agreement between the 2 devices was also documented with a mean difference of −15.3 (limits of agreement [LoA] −246.5 to 277.1) mm for SL-AOD and 0.006 (LoA −0.096 to 0.108) mm in SL-TISA. ConclusionBoth devices were able to provide consistent angle measurements, but repeatability and reproducibility were better in Cirrus SD-OCT than in Nidek RS 3000 Advanced SD-OCT.