Assessment of optic disc parameters among healthy adult Malays by Heidelberg Retinal Tomograph II

BACKGROUND: This study aims to assess the optic disc characteristics in healthy adult Malays and to correlate them with age, gender and refractive errors. DESIGN: Cross-sectional study. PARTICIPANTS: A total of 200 voluntary participants (106 women and 94 men) among Malay students aged 20 to 37 years at Health Campus, Universiti Sains Malaysia. METHODS: The relationship between Heidelberg Retinal Tomograph parameters with age, gender and refractive error were analysed with correlation tests and multiple linear regression analyses. MAIN OUTCOME MEASURES: Twelve parameters, that is, disc area, rim area, cup area, cup to disc area, cup volume, rim volume, height variation contour, cup shape measure, mean cup depth, maximum cup depth, mean retinal nerve fibre layer thickness and retinal nerve fibre layer cross-sectional area. RESULTS: Disc area, rim area and cup : disc area ratio averaged 2.24 ± 0.52 (mean ± standard deviation), 1.64 ± 0.32 and 0.25 ± 0.12 mm(2) , respectively. Five parameters (disc area, cup area, cup volume, cup : disc area ratio and mean retinal nerve fibre layer thickness) showed statistically significant difference between men and women. Age was negatively and significantly correlated with rim area with coefficient r = -0.21, P = 0.003. All optic disc parameters were significantly correlated (P < 0.05) with disc area, except cup shape measure. CONCLUSIONS: One or more of optic disc parameters were affected significantly by age, gender and disc area in healthy adult Malays' eyes. These factors need to be considered during the evaluation of optic disc.