Corneal thickness mapping by 3D swept-source anterior segment optical coherence tomography

{PURPOSE:} To assess accuracy and repeatability of central corneal thickness ({CCT)} measurements obtained by swept-source anterior segment optical coherence tomography ({AS-OCT)}, spectral-domain retinal {OCT} with corneal module and ultrasound pachymetry ({USP)}, and to assess repeatability of pachymetric mapping with {AS-OCT.} {METHODS:} 50 healthy volunteers were recruited. A single, experienced operator analysed the right eye of each participant twice in the same session with {AS-OCT} ('corneal map' routine), retinal {OCT} and {USP.} {CCT} measurements were compared using repeated-measures analysis of variance, Bonferroni test, Pearson correlation and Bland-Altman plots. Repeatability of thickness maps and {CCT} measurements were assessed using Alpha of Cronbach, intraclass correlation coefficient ({ICC)} and coefficient of repeatability. {RESULTS:} Mean {CCT±SD} was 540±28.9 μm for {AS-OCT}, 544±29.5 μm for retinal {OCT} and 549.3±31.7 μm for {USP;} the differences were statistically significant (p{\textless}0.01). {CCT} measurements obtained with the three instruments were highly correlated: r was 0.965 for {AS-OCT/USP}, 0.962 for retinal {OCT/USP} and 0.984 for {AS-OCT/retinal} {OCT} comparison. The repeatability of {CCT} measurements was higher for {AS-OCT} than for the other devices (p{\textless}0.001). Repeatability of pachymetric maps was excellent ({ICC=0.999).} {CONCLUSIONS:} Pachymetric maps by swept-source {AS-OCT} showed excellent repeatability. {CCT} measurements obtained by {AS-OCT}, {USP} and retinal {OCT} were highly correlated although not identical