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

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Imaging

Background:

• Keratoconus is a progressive thinning of the cornea.
• Retinal nerve fiber layer (RNFL) thickness is a key indicator of glaucoma and other optic neuropathies.
• Accurate RNFL measurements are crucial for diagnosis and monitoring.

Purpose of the Study:

• To assess the intrasession reproducibility of peripapillary RNFL thickness measurements using spectral-domain optical coherence tomography (SD-OCT).
• To compare RNFL measurement reproducibility between eyes with keratoconus and normal control eyes.

Main Methods:

• Peripapillary RNFL thickness was measured three times in one eye per participant during a single visit.
• Measurements were performed using SD-OCT with integrated eye-tracking and retest functions.
• Reproducibility was quantified using within-subject standard deviation (Sw), coefficient of variation (CV), and intraclass correlation coefficient (ICC).

Main Results:

• Overall global RNFL thickness showed high reproducibility in control eyes (Sw: 1.43 ± 0.24, CV: 1.28%, ICC: 0.969).
• Eyes with keratoconus demonstrated comparable intrasession reproducibility (Sw: 1.41-1.57, CV: 1.18-1.37%, ICC: 0.951-0.977).
• The ICC values for keratoconus eyes ranged from 0.951 to 0.977, indicating good consistency.

Conclusions:

• SD-OCT measurement of peripapillary RNFL thickness exhibits good intrasession reproducibility in eyes affected by keratoconus.
• These findings suggest SD-OCT is a reliable tool for evaluating RNFL in keratoconus patients.