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Reliability of gaze-contingent perimetry
Nikita Thomas1,2, Jennifer H Acton1, Jonathan T Erichsen1
1School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, Wales, CF24 4HQ, UK.
Behavior Research Methods
|September 11, 2023
Summary
Continuous gaze-contingency (CGC) offers a more accurate method for visual field testing, especially for individuals with nystagmus. This new technique improves reliability and precision in measuring visual field sensitivity.
Area of Science:
- Ophthalmology
- Neuroscience
- Vision Science
Background:
- Standard automated perimetry is limited by eye movements, affecting reliability in patients with unstable fixation like nystagmus.
- Existing microperimetry with partial gaze-contingency (PGC) offers partial correction for eye movements.
- Accurate visual field testing is crucial for detecting and monitoring vision loss.
Purpose of the Study:
- To introduce and evaluate a novel 'continuous gaze-contingency' (CGC) method for visual field examination.
- To assess the accuracy and reliability of CGC compared to PGC and no gaze-contingency (NoGC).
- To demonstrate the utility of CGC in individuals with infantile nystagmus and healthy observers.
Main Methods:
- Developed and implemented a continuous gaze-contingency (CGC) visual field testing system.
- Compared CGC with PGC and NoGC in measuring the blind spot edges in infantile nystagmus cases.
- Evaluated stimulus positional error and test-retest variability of CGC, PGC, and NoGC in healthy participants.
Main Results:
- CGC demonstrated greater accuracy in measuring blind spot edges in infantile nystagmus compared to PGC and NoGC.
- CGC achieved the lowest stimulus positional error (± 0.29°) in healthy observers, outperforming PGC (± 0.54°) and NoGC (± 0.81°).
- CGC exhibited test-retest variability comparable to or better than PGC and NoGC.
Conclusions:
- Continuous gaze-contingency (CGC) is a reliable and precise method for visual field examination in healthy individuals.
- CGC shows promise for accurate visual field threshold estimation, even in patients with infantile nystagmus.
- This novel approach enhances the reliability of visual field testing, particularly for individuals with fixation instability.
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