Test–retest variability of Randot stereoacuity measures gathered in an unselected sample of UK primary school children
- 1Private Practice, Stotfold, Hertfordshire, UK
- 2School of Health Studies, Institute of Health Research, University of Bradford, Bradford, UK
- 3School of Optometry and Vision Science, University of Bradford, Bradford, UK
- Correspondence to Brendan T Barrett, School of Optometry & Vision Science, University of Bradford, Richmond Road, Bradford BD7 1DP, UK;
Contributors PA designed the study, monitored data collection, input data to spreadsheet, contributed to analysis and interpretation of data, and revised the paper. AJS conducted the statistical analysis, and contributed to the writing and revision of the paper. BTB also designed the study, contributed to analysis and interpretation of data, and wrote the initial draft of the paper.
- Accepted 12 November 2011
- Published Online First 8 February 2012
Aim To determine the test–retest reliability of the Randot stereoacuity test when used as part of vision screening in schools.
Methods Randot stereoacuity (graded-circles) and logMAR visual acuity measures were gathered in an unselected sample of 139 children (aged 4–12, mean 8.1±2.1 years) in two schools. Randot testing was repeated on two occasions (average interval between successive tests 8 days, range: 1–21 days). Three Randot scores were obtained in 97.8% of children.
Results Randot stereoacuity improved by an average of one plate (ie, one test level) on repeat testing but was little changed when tested on the third occasion. Within-subject variability was up to three test levels on repeat testing. When stereoacuity was categorised as ‘fine’, ‘intermediate’ or ‘coarse’, the greatest variability was found among younger children who exhibited ‘intermediate’ or ‘coarse’/nil stereopsis on initial testing. Whereas 90.8% of children with ‘fine’ stereopsis (≤50 arc-seconds) on the first test exhibited ‘fine’ stereopsis on both subsequent tests, only ∼16% of children with ‘intermediate’ (>50 but ≤140 arc-seconds) or ‘coarse’/nil (≥200 arc-seconds) stereoacuity on initial testing exhibited stable test results on repeat testing.
Conclusions Children exhibiting abnormal stereoacuity on initial testing are very likely to exhibit a normal result when retested. The value of a single, abnormal Randot graded-circles stereoacuity measure from school screening is therefore questionable.
- Childrens vision's vision
- depth perception
- school vision screening
- clinical trial
- child health (paediatrics)
- contact lens
- visual perception
Competing interests None.
Patient consent Obtained.
Ethics approval Ethics approval was provided by the ethics committee of the University of Bradford.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement Data available on request from the corresponding author: