Intrasession reproducibility of RNFL Thickness measurements using SD-OCT in eyes with keratoconus

BACKGROUND AND OBJECTIVE: To evaluate the intrasession reproducibility of the peripapillary retinal nerve fiber layer (RNFL) thickness measurements obtained by spectral-domain optical coherence tomography (SD-OCT) in eyes with keratoconus and normal eyes. PATIENTS AND METHODS: Peripapillary RNFL thickness measurements with SD-OCT were repeated three times during the same visit using the eye tracker and retest function in one eye of each participant. Reproducibility was evaluated using withinsubject standard deviation (Sw), coefficient of variation (CV), and intraclass correlation coefficient (ICC). RESULTS: For the overall global RNFL thickness, the values of the three parameters were Sw (± 1.96 standard error) 1.43 ± 0.24, CV 1.28%, ICC (95% confidence interval) 0.969 (range: 0.947-0.983) in control eyes and Sw (± 1.96 standard error) from 1.41 ± 0.26 to 1.57 ± 0.34, CV from 1.18% to 1.37%, and ICC (95% confidence interval) from 0.951 (range: 0.909-0.976) to 0.977 (range: 0.938-0.993) in eyes with keratoconus. CONCLUSION: Measurement of peripapillary RNFL thickness by SD-OCT shows a good intrasession reproducibility in eyes with keratoconus.