Ocular blood flow tonometer reproducibility: the effect of operator experience and mode of application

Abstract

Objective: The purpose of this study was to investigate whether the effect of learning and the reproducibility of measurements varied between the two methods of application (hand-held or slit-lamp mounted) of the ocular blood flow (OBF) tonometer.Method: Five consecutive measurements by each method were taken at one examination session on one eye of 35 healthy adults (mean age 36.6 years and range 17–84 years). The subjects were seated for all measures and the sequence of tonometer method was randomised between subjects.Results: A new operator does exhibit a significant learning effect and this learning effect is of a greater magnitude for the hand-held technique. No significant difference was found between methods for pulsatile ocular blood flow (POBF), IOP, pulse amplitude and heart rate. Both methods of application had a high coefficient of reliability for POBF: 0.91 for slit-lamp and 0.89 for hand-held.Conclusions: We conclude that results from both methods of OBF tonometer application are reliable and either method can be used for clinical and research studies. However it is important that new operators gain sufficient experience with the OBF tonometer to avoid initial operator-induced variability.