To determine the repeatability of the optical characteristics of the retinal nerve fiber layer (RNFL) measured with optical coherence tomography (OCT) in healthy Chinese individuals.

In this cross-sectional study, 50 eyes of 50 normal subjects were consecutively recruited. RNFLs were imaged twice using a Cirrus OCT device with a 5-line raster macular scan and an optic disc cube mode in one day by a single operator. Customized software was used to measure RNFL optical characteristics, including optical density and the attenuation coefficient. Repeatability of OCT and customized software measurements were described by intraclass correlation coefficients (ICCs) , coefficients of variation (COVs) and the Bland-Altman method.

The mean and standard deviation of age were 51.2±8.1 years. The mean and standard deviations of macular RNFL thickness, optical density and the attenuation coefficient were 34.38±3.45 μm, 117.90±6.02 grey and 1.99±0.16, respectively. The mean and standard deviations of optic disc RNFL thickness, optical density and the attenuation coefficient were 89.07±3.19 μm, 138.10±18.25 grey and 3.48±0.64, respectively. All the evaluated RNFL parameters had good to excellent reproducibility. ICC ranged from 0.712 to 0.952 and COV ranged from 2.20% to 6.54%. The bias between two OCT measurements were -0.01 grey/0.33 grey and 0.01/-0.01, respectively, for macular and optic disc RNFL optical density and attenuation coefficients. Customized software showed excellent reproducibility in RNFL measurements. ICC ranged from 0.928 to 0.979 and COVs all bellowed 6% (1.35%-4.24%) for RNFL parameters measurement.

In our population of normal adult Chinese eyes, there is good repeatability of RNFL optic characteristics measured by OCT and customized software.

Tomography, optical coherence; Repeatability; Retinal nerve fiber layer; Optical characters; Optical density; Attenuate coefficient