Improving Spatial Resolution and Test Times of Visual Field Testing Using ARREST

Abstract

PurposeCorrectly classifying progression in moderate to advanced glaucoma is difficult. Pointwise visual field test–retest variability is high for sensitivities below approximately 20 dB; hence, reliably detecting progression requires many test repeats. We developed a testing approach that does not attempt to threshold accurately in areas with high variability, but instead expends presentations increasing spatial fidelity.MethodsOur visual field procedure Australian Reduced Range Extended Spatial Test (ARREST; a variant of the Bayesian procedure Zippy Estimation by Sequential Testing [ZEST]) applies the following approach: once a location has an estimated sensitivity of <17 dB (a “defect”), it is checked that it is not an absolute defect (<0 dB, “blind”). Saved presentations are used to test extra locations that are located near the defect. Visual field deterioration events are either: (1) decreasing in the range of 40 to 17 dB, (2) decreasing from >17 dB to “defect”, or (3) “defect” to blind. To test this approach we used an empirical database of progressing moderate-advanced 24-2 visual fields (121 eyes) that we “reverse engineered” to create visual field series that progressed from normal to the end observed field. ARREST and ZEST were run on these fields with test accuracy, presentation time, and ability to detect progression compared.ResultsWith specificity for detecting progression matched at 95%, ZEST and ARREST showed similar sensitivity for detecting progression. However, ARREST used approximately 25% to 40% fewer test presentations to achieve this result in advanced visual field damage. ARREST spatially defined the visual field deficit with greater precision than ZEST due to the addition of non–24-2 locations.ConclusionsSpending time trying to accurately measure visual field locations that have high variability is not productive. Our simulations indicate that giving up attempting to quantify size III white-on-white sensitivities below 17 dB and using the presentations saved to test extra locations should better describe progression in moderate-to-advanced glaucoma in shorter time.Translational RelevanceARREST is a new visual field test algorithm that provides better spatial definition of visual field defects in faster test time than current procedures. This outcome is achieved by substituting inaccurate quantification of sensitivities <17 dB with new spatial locations.

Custom extraction of macular ganglion cell-inner plexiform layer thickness more precisely co-localizes structural measurements with visual fields test grids

“…The locations of the projected VF stimuli were corrected for lateral displacement of GCs relative to the underlying stimulated photoreceptors due to elongation of Henle fibers at the central fovea 16 , 20 , as per Drasdo et al’s Fig. 6 27 and consistent with previous studies applying this methodology 7 , 16 , 18 , 33 . Irrespective of individual fovea to optic disc tilts, the VF-based paradigms were maintained at a tilt of 0° to maintain consistency with natural head positioning during VF testing and therefore ensure that structural measurements were accurately extracted over retinal locations stimulated by VF test points (Fig.…”

Increasing the Spatial Resolution of Visual Field Tests Without Increasing Test Duration: An Evaluation of ARREST

“…8 ARREST is designed to add additional locations in areas of steep visual field gradient without increasing test duration. 3 Second, current test procedures repeatedly assess perimetrically blind locations at each subsequent test visit. Testing locations that are well established to be at the measurement floor (0 dB) provides no additional information.…”

“…ARREST does not retest locations with established sensitivity of < 0 dB. 3 The third limitation of current procedures is the well-studied higher test-retest variability in moderate and advanced visual field loss, [11][12][13][14][15][16] which reduces the accuracy of sensitivity estimates. Recently, Gardiner et al 16 have shown that testing locations with sensitivity below approximately 15 to 19 dB with current SAP implementations does not provide information that is particularly clinically useful due to the degree of measurement noise.…”

“…The saved presentations are used to increase spatial density to assess new locations adjacent to established scotomas. 3 For locations where sensitivity is greater than 17 dB, normal thresholding approaches apply. In summary, the ARREST approach only modifies the current test grid and test algorithm when there are visual field sensitivities < 17 dB in the previous visual field test.…”

“…In simulation, the performance of ARREST was comparable to Zippy Estimation by Sequential Testing (ZEST) on a 24-2 test grid in detecting visual field progression, while improving spatial resolution with 25% to 40% fewer stimulus presentations than the ZEST 24-2 test procedure. 3 The current study was designed as a feasibility study of the ARREST approach in people with glaucomatous visual field loss, to determine whether the main predictions from computer simulation are realized in human testing. We compared the performance of ARREST against ZEST (a variant of procedures used in commercial perimeters).…”