Abstract
Purpose :
Visual field tests using the HFA3 Model 860 (ZEISS, Dublin, CA) conduct threshold testing for multiple points across the visual field. Due to the length of testing time and the nature of responding to varying visual stimuli, visual field tests necessarily involve attention. Sustained attention skills and response styles vary across patients, and visual field test results may be affected by cognitive factors unrelated to vision. Attention effects on visual field testing would also be expected to vary with the duration of the test, as ability to sustain attention decreases as duration increases. The purpose of this study is to compare measures of reliability on the SITA Standard 24-2C and SITA Faster 24-2C on the HFA 3 to patient response styles, as measured by a continuous performance test, to measure their degree of interaction.
Methods :
The Cogquiz (www.cogquiz.com) Continuous Performance Test (CPT) was administered to 10 healthy normal participants who had also been administered the SITA Faster 24-2C and SITA Standard 24-2C tests. Participants with a low response time (RT) on the CPT are classified as having a liberal response style that emphasizes speed over accuracy. Participants with a high RT are classified as having a conservative response style that emphasizes accuracy over speed. Correlations between errors (loss of fixation and false positives), on the visual field tests and RT on the CPT were run to determine the degree of interaction between attention and visual field test reliability.
Results :
Participants with lower RT on the CPT (M=484.2ms) committed more errors on the visual field tests (M=3.2) than participants with higher RT (Mean RT=598.8ms; Mean errors=1.5). Differences between the two groups were significant (T=2.61, p<0.05). Response time was strongly negatively correlated with errors on the HFA tests (r=-0.71, p<0.05).
Conclusions :
Patients with a liberal response style showed a greater number of errors on the SITA Standard 24-2C and SITA Faster 24-2C visual field tests than patients with a more conservative response style. While all participants made errors on the SITA Standard test, only those with latency scores greater than one standard deviation below the mean made any errors on the SITA Faster test. This suggests that for some patients with highly liberal response styles, the SITA Faster visual field test will yield more reliable results than longer visual field tests.
This is a 2020 ARVO Annual Meeting abstract.