Abstract
Purpose :
Visual field assessment lacks precision in areas of moderate-advanced damage. ARREST is a new test algorithm that doesn’t attempt to threshold accurately in such areas, but instead increases spatial fidelity [1]. Previous assessment of ARREST has been via computer simulation. This study aimed to verify the main performance predictions from such simulations: namely that ARREST should enable improved spatial information than a threshold 24-2 test, in similar time.
Methods :
ARREST, a variant of ZEST, applies the following: once a location has estimated sensitivity less than 17dB, we check that it is not an absolute defect (<0dB). Saved presentations are used to test extra locations near the scotomata, aiming for a total number of 250 presentations. Nine participants with spatially well circumscribed visual field defects due to glaucoma participated. ARREST testing was implemented using the Open Perimetry Interface on an O900 perimeter (Haag-Streit AG), as was a reference procedure, ZEST. Within the visual field quadrant with the highest sensitivity gradient, a high-definition visual field was measured twice using the OPI on the fundus-tracked Compass perimeter (CenterVue, SpA) as a separate reference. The agreement between the measured points (ARREST) and the high-fidelity fixation stabilised fields was compared to the agreement from simple interpolation of ZEST.
Results :
There was no significant difference in test duration between ARREST and ZEST (mean presentations of 247 for ZEST and 256 for ARREST: p=0.48). The median number of additional test locations added by ARREST was 7 (range: 2-9 locations). The agreement between ARREST and the high-density fields was better than simple interpolation in 7 of the 9 eyes. Examples of data for 4 participants is shown in Figure 1.
Conclusions :
ARREST substitutes presentations typically used to collect variable thresholds below 17dB to test extra locations. Improved spatial fidelity may improve understanding of the relationship between structural and functional damage in moderate to advanced glaucoma and allow assessment of progression in more damaged visual fields.
1.Turpin, Morgan, McKendrick, TVST, 2018: 7.5.35
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.