Inter-examiner agreement of the AS-OCT Visante corneal thickness

Abstract

Purpose To determine the inter-examiner agreement of the manual values of central and peripheral corneal thickness as measured by optical coherence tomography (AS-OCT Visante) and to assess the agreement between AS-OCT Visante pachymetry, Orbscan II and ultrasound pachymetry (USP). Methods Central and peripheral (4.0 mm from the corneal centre to the superior, inferior, nasal and temporal areas) corneal thickness was analyzed in 30 eyes of 15 patients (mean age, 26.8 ± 6.8 years), with the AS-OCT Visante both automatically (Global-Pachymetry Map) and manually (Flap Tool). The Orbscan II and USP (Corneo-Gage Plus) pachymetry were also assessed. Inter-examiner reproducibility for the manual values of the AS-OCT Visante was calculated. Automatic and manual AS-OCT pachymetries were compared for all corneal locations. Results Good inter-examiner agreement was obtained for the manual values of the AS-OCT Visante for all locations studied (p = 1.00). The automatic value was significantly different from the manual value for both central and inferior pachymetry (37 ± 10 μm and 27 ± 11 μm respectively; p < 0.05). Good linear correlation was found between the automatic AS-OCT Visante, the Orbscan II and USP, although there were statistically significant differences (p < 0.01) between all of the corneal locations, with the exception of the manual values of the AS-OCT Visante and the Orbscan II for the central corneal thickness (CCT) measures. Conclusions The AS-OCT Visante has high inter-examiner agreement for manual values (Flap Tool). The automatic analysis (Global-Pachymetry Map) provides different corneal thickness values (centrally and peripherally) than those obtained manually for the same corneal scan.