Repeatability, reproducibility and normative ranges for EyeGuide Focus testing system in elite male rugby players

Objectives

The EyeGuide Focus system is a simple, portable, test of visual tracking with potential use for concussion screening. This study investigated the repeatability, reproducibility, distribution, and modifiers of EyeGuide Focus measurements in healthy elite Rugby players.

Design

Cross sectional repeated measures study and controlled pre-test post-test sub-study.

Methods

EyeGuide Focus testing was performed in a medical room at rest. Test-retest repeatability (within-subject standard deviation (Sw), coefficient of variation (CV), repeatability coefficient (RC)) and reliability intra-class correlation coefficient (ICC A,1) of 3 test results were evaluated. The distribution of best score across replicates was then examined using summary statistics, and the influence of subject characteristics investigated. A controlled pre-test post-test sub-study examined the effect of exercise on best EyeGuide Focus score using an analysis of covariance (ANCOVA).

Results

A total of 769 elite male Rugby players underwent EyeGuide Focus testing. Repeated test scores demonstrated positively skewed distributions. Test-retest repeatability (Sw 1.46, CV 46.0 %, RC 2.85, natural log transformed data) and reliability (ICC 0.41, natural log transformed data) were low. The distribution of best EyeGuide Focus score was unaffected by previous concussion, eye conditions, or age. No learning or exercise effects were apparent in the controlled pre-test post-test sub-study (ANCOVA, n = 89, p = 0.69).

Conclusions

EyeGuide Focus test-retest repeatability and reliability were low and could limit diagnostic accuracy.

Best test score achieved across repeated measurements is a possible metric for operationalisation and future research is required to determine if this differs in patients with concussion compared to normal subjects.