Agreement Between Spectral-Domain and Swept-Source Optical Coherence Tomography Retinal Thickness Measurements in Macular and Retinal Disease.

INTRODUCTION: To assess inter-device agreement in optical coherence tomography-derived retinal thickness measurements in patients with known macular conditions between spectral-domain and swept-source optical coherence tomography (OCT). METHODS: Two hundred seventy-two subjects were included in the study. They consisted of 91 male (33.5%) and 181 female (66.5%) subjects, and 132 left (48.5%) and 140 right (51.5%) eyes. Each subject underwent spectral-domain OCT (SD-OCT, Spectralis, Heidelberg Engineering; RTVue XR Avanti XR HD, Optovue) and swept-source OCT (SS-OCT; DRI-OCT-1, Atlantis, Topcon) in a single imaging session performed by the same clinical trial-certified technician. The comparison of retinal thickness reproducibility between devices was performed using Bland-Altman analyses and across the entire data set using the intraclass correlation coefficient (ICC). RESULTS: The ICC of the retinal thickness measurements (95% confidence interval) made using all three OCT instruments was 0.81 (0.77-0.84). The mean difference in mean retinal thickness between Spectralis SD-OCT and Topcon SS-OCT was 59.1 µm (95% limit of agreement [LoA] -21.7 to 139.8 µm). The mean difference in mean retinal thickness between Optovue SD-OCT and Topcon SS-OCT was 21.8 µm (95% LoA -34.7  to 78.3 µm). CONCLUSIONS: Retinal layer thickness measurements vary between SS-OCT and SD-OCT devices. We describe inter-device agreement in retinal thickness between SS-OCT and SD-OCT in patients with macular conditions. Clinicians should be aware of the differences in retinal thickness values when imaging patients using different OCT devices and should consider using the same OCT device model in order to monitor clinical change. TRIAL REGISTRATION: ClinicalTrials.gov Identifier (NCT02828215).