The morphology of the optic nerve head in the Singaporean Chinese population (the Tanjong Pagar study): part 1—optic nerve head morphology
- R R A Bourne1,2,3,4,
- P J Foster4,5,
- C Bunce4,
- T Peto4,
- R A Hitchings4,
- P T Khaw4,5,
- S K L Seah6,
- D F Garway-Heath5,6
- 1Huntingdon Glaucoma Diagnostic & Research Centre, Huntingdon, UK
- 2Research Unit, Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- 3Anglia Ruskin University, Cambridge, UK
- 4Moorfields Eye Hospital, London, UK
- 5UCL Institute of Ophthalmology NIHR Biomedical Research Centre, London, UK
- 6Singapore National Eye Centre, Singapore
- Professor R Bourne, Huntingdon Glaucoma Diagnostic & Research Centre, Department Ophthalmology, Hinchingbrooke Hospital, Huntingdon PE29 6NT, UK; rupert.bourne{at}lshtm.ac.uk
- Accepted 14 September 2007
Abstract
Background/aims: To investigate the correlation between optic disc parameters and their association with demographic variables in a Chinese population.
Methods: Disc data were obtained from 929 subjects aged ≥40 years from the Tanjong Pagar glaucoma survey of Singapore, using a novel planimetric method of sequential stereo-photographs. Biometric data (refractive error, keratometry, axial length, anterior chamber depth, lens thickness) were used to calculate ocular magnification. Camera magnification was quantified with a model eye. A “normal” dataset of 622 subjects was generated by exclusion of subjects with abnormal results on psychophysical testing, an occludable angle or an intraocular pressure >97.5th percentile in either eye.
Results: Median disc area (DA), cup area (CA), and rim area (RA) were 2.09 (range 1.28–4.01) mm2, 0.69 (0.01–1.90) mm2 and 1.38 (0.82–2.50) mm2, respectively. There was strong evidence of an association between DA and RA (Spearman’s rho 0.624, p<0.001). DA and RA were significantly greater in men (median DA = 2.20; range 1.30–3.56; median RA, 1.45; range 0.85–2.30) than women (median DA, 2.00; range 1.28–4.01; median RA, 1.36; range 0.82–2.49, p<0.001). DA increased with age (Spearman’s rho 0.115, p = 0.004), while RA was unrelated (rho –0.041; p = 0.308).
Conclusions: The morphometric characteristics of optic discs in Chinese Singaporeans are very similar to those described in other groups, with the temporal sector rim having the smallest area. Disc and rim areas vary with sex (men>women). Disc area (but not that of the rim) increases with age.
Footnotes
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The data-collection phase of this study was funded by the National Medical Research Council (Singapore). The International Glaucoma Association funded Mr Rupert Bourne’s research fellowship. This research has received a proportion of its funding from the Department of Health’s National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology. The views expressed in this publication are those of the authors and not necessarily those of the Department of Health.
