Retinal nerve fiber layer measurement of the Hong Kong Chinese population by optical coherence tomography

Abstract

Purpose: To obtain retinal nerve fiber layer (RNFL) measurements by optical coherence tomography in a local, normal Hong Kong Chinese population and to identify the correlation of the measurement with age cross -sectionally. Methods: A total of 129 normal Hong Kong Chinese volunteers of different age groups were recruited for this study. The RNFL was measured by optical coherence tomography (OCT; OCT 2000; Humphrey Instruments, San Leandro, CA). Results: Mean ± SD peripapillary RNFL measurements at the superior, inferior, temporal, and nasal regions were 145 ± 24, 154 ± 26, 98 ± 32, and 87 ± 16 μm, respectively. There was a highly significant negative correlation in average RNFL measurement with increasing age (3.3 μm per decade, P < 0.001). A significant negative correlation with increasing age was also identified in the RNFL measurements in all the regions (P < 0.05) and decreased at similar extent. Conclusion: The RNFL thickness of the Hong Kong Chinese population, as measured by OCT, appeared to decrease over time. The OCT normative values used for determining RNFL measures "outside of normal" should be developed on an age-specific, or at least age-adjusted, basis.