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 within-subject 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.