Variability of Measurements of the Optic Nerve Head and Peripapillary Retinal Blood Flow by Scanning Laser Doppler Flowmetry

Kim, Dong Myung; Chung, Eui Sang

Abstract

The objective of this study was to evaluated the ariability of measurements of the optic nerve head(ONH) and peripapillary retinal blood flow using Heidelberg Retina flowmeter. Ten eyes of 10 ocularly normal subjects underwent scanning laser Doppler flowmetry. Each eye was scanned in 2 sessions which were separated by 30 minutes. In each session, 5 scans centerd on the ONH using a 10*2.5 degree scan angle were obtained. We identified 10 locations(4 locations in the cup of ONH) and took measurements at the same locations in all scans. The coefficient of variation(CVs, %) for volume, flow, and velocity ranged from 8.1 to 13.0%, 9.9 to 16.0%, and 9.9 to 14.6%, respectively. The CVs of measurements in the neural rim, peripapillary retina, and cup ranged from 9.1to 15.9%, 8.1 to 10.7%, and 11.8 to 16.0%, respectively. The Pearson's coefficients of correlation (r) showed significant correlation in the all parameters in the peripapillary retina and in the flow and velocity in the neural rim. In conclusion, scanning laser Doppler flowmetry provides reproducible measurement of ONH and retinal blood flow.