Observer variation in the sonographic measurement of optic nerve sheath diameter in normal adults

Ballantyne, S.A., O'Neill, G., Hamilton, R. and Hollman, A.S. (2002) Observer variation in the sonographic measurement of optic nerve sheath diameter in normal adults. European Journal of Ultrasound, 15(3), pp. 145-149. (doi: 10.1016/S0929-8266(02)00036-8) (PMID:12423741)

Abstract

Aim: To quantify the observer variation in the sonographic measurement of optic nerve sheath diameter (ONSD) in normal adults. Materials and methods: Sixty-seven normal adult volunteers underwent ultrasound examination of each eye by three independent observers using a 7 MHz sector probe. Three measurements were made of each eye by each observer and a mean value calculated for each eye. Median and 5th–95th centile values for both intra- and inter-observer variation were calculated for the three observers. Results: The median intra-observer variation was ±0.1 mm, with 5th–95th centile values of ±0–0.4 mm. The median inter-observer variation was ±0.2–0.3 mm, with 5th–95th centile values of ±0–0.7 mm. Careful review of examination technique by the three observers after the first 17 examinations was shown to reduce both intra- and inter-observer variation. Conclusion: The sonographic measurement of ONSD is a readily learned, reproducible technique with low intra- and inter-observer variation. The average inter-observer variation (±0.2 mm) is comparable to the inherent variability of the ultrasound machine. The importance of standardisation of examination technique is stressed.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Ballantyne, Dr Stuart and Hamilton, Dr Ruth
• Authors: Ballantyne, S.A., O'Neill, G., Hamilton, R., and Hollman, A.S.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: European Journal of Ultrasound
• Publisher: Elsevier
• ISSN: 0172-4614
• ISSN (Online): 1438-8782
• Published Online: 01 November 2002