Corneal epithelial thickness changes as imaged by Fourier-domain optical coherence tomography in eyes with keratoconus

Abstract

Purpose The purpose of this study was to document changes in the corneal epithelium as imaged by Fourier-domain optical coherence tomography (OCT) in cases of keratoconus.Patients and methods This is a comparative cross-sectional study including 20 eyes of 14 patients with keratoconus (n=20, study group) and 16 eyes of eight normal individuals (n=16, control group). Both groups were imaged using Scheimpflug imaging corneal topography and Fourier-domain AS-OCT system. Corneal epithelial thickness maps obtained by the AS-OCT system were studied and compared between the two groups.Results There was no statistically significant difference in mean corneal epithelial thickness between study and control groups (unpaired Student’s t-test, P<0.05). Minimum corneal epithelial thickness was statistically significantly less and maximum corneal epithelial thickness was statistically significantly more in the study group compared with the control group (unpaired Student’s t-test, P<0.05). Corneal epithelial thickness was least in the central, temporal, and inferotemporal sectors of the study group. A distinct pattern of epithelial thinning over the thinnest pachymetry and highest back elevation with varying degrees of surrounding epithelial thickening located in the inferotemporal quadrant was observed in 71.43% of the study group.Conclusion Recognizable corneal epithelial thickness changes are seen in keratoconic eyes. The diagnostic potential of such changes need to be further investigated.