Relationship between age and peripapillary retinal nerve fibre layer thickness: An optical coherence tomography study

Abstract

Objective: To evaluate the relationship between age and peripapillary retinal nerve fibre layer thickness in healthy Chinese subjects. Design: Cross-sectional study. Setting: Regional hospital, Hong Kong. Participants: Healthy volunteers (n=218) of Chinese ethnicity with spherical equivalent of -6 to +4 dioptres were recruited for study from October 2001 to March 2003. Ocular examination was carried out and measurements of peripapillary retinal nerve fibre layer thickness were performed using optical coherence tomography (Carl Zeiss Humphrey OCT 2 machine), in a circular pattern of 3.4 mm diameter, centred on the optic disc. Main outcome measures: Mean retinal nerve fibre layer thickness and age. Results: The mean age was 40 (standard deviation, 17; range, 11-69) years. The mean peripapillary retinal nerve fibre layer thickness was 111.6 (standard deviation, 18.5; range, 52.0-155.0) μm. Age correlated significantly with peripapillary retinal nerve fibre layer thickness (r= -0.28, P<0.0001). Conclusion: Mean peripapillary retinal nerve fibre layer thickness (based on optical coherence tomography) correlates negatively with age, which can interfere with the assessment and monitoring of glaucoma patients. An age-adjusted normogram may be necessary to interpret results.