Repeatability of quantitative measurements of anterior segment analysis with swept‐source AS‐OCT in dry eye, ocular surface disease and healthy eyes

Abstract

AbstractPurpose: Dry eye and ocular surface disease (OSD) are the most common causes of eye discomfort with up to 50%1 of the global population affected. Anterior segment optical coherence tomography (AS‐OCT) is essential to diagnose and track ocular surface changes. This study aims at assessing the precision of a modern swept source AS‐OCT in OSD vs healthy control.Methods: Five clinical groups were included: G1 = Sjögren's syndrome (n = 46); G2 = Ocular Mucous Membrane Pemphigoid, Graft‐versus‐Host Disease, etc. (n = 58); G3 = Meibomian Gland Disease (n = 47); G4 = Miscellaneous (Neurotrophic, Exposure, Transplant, etc.) (n = 36); G5 healthy controls (n = 41). Three consecutive measurements using a radial scan mode were collected using the AS‐OCT Casia2 (Tomey, Japan) and the repeatability limits (RLs) were calculated. The following parameters were obtained: anterior chamber depth (ACD), AC width (ACW), angle opening distance (AOD) and angle recess area (ARA) both at 250, 500 and 750 μm, angle to angle (ATA), central thickness apex (CTapex), lens vault (LV), trabecular iris angle (TIA) and trabecular iris‐space area (TISA) both at 250, 500 and 750 μm. Dry eye metrics such as OSDI® questionnaire, fluorescein break‐up time (FBUT), tear meniscus height (TMH), conjunctival inflammation (INFLCONJ) and ocular surface staining (OSS) were considered.Results: The higher RLs values were observed within the G4 cohort considering AOD (0.28, 0.29, 0.36, 0.35, 0.43 vs G5 0.18, 0.21, 0.18, 0.20, 0.26 mm),ARA (0.08, 0.10, 0.16, 0.18, 0.25, 0.27 vs. G5 0.06, 0.06, 0.09, 0.10, 0.14, 0.15 mm2), CTapex (66.12 vs. G5 13.55 μm), TIA (33.90, 22.57, 14.55, 20.02 vs. G5 30.94, 18.31, 9.44, 14.76 degrees) and TISA (0.06, 0.07, 0.14, 0.15, 0.23, 0.24 vs. G5 0.04, 0.05, 0.08, 0.09, 0.12, 0.14 mm2). G1 cohort reported the worst dry eye metrics (OSDI 52.90 ± 20.58 score, FBUT 3.51 ± 2.36 s, TMH 0.10 ± 0.07 mm, INFLCONJ 1.07 ± 1.78 score, OSS 4.27 ± 2.35 score).Conclusions: This is the first study to consider anterior segment analysis repeatability limits in OSD vs healthy cohorts with the AS‐OCT Casia2. Despite G1 cohort reported the worse dry eye metrics, the higher repeatability limits were observed in the G4 Miscellaneous group.Reference1. Stapleton, F. et al. TFOS DEWS II Epidemiology Report. Ocular Surface 15, 334–365, doi:10.1016/j.jtos.2017.05.003 (2017).