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Philip M. Bronstad; Measuring the usefulness of strabismic field expansion in hemianopia. Invest. Ophthalmol. Vis. Sci. 2018;59(9):637.
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© ARVO (1962-2015); The Authors (2016-present)
To determine the usefulness of the expanded visual field patients were tested in a driving simulator. While patients drove they pressed the horn button to indicate that they detected pedestrian hazards that appeared multiple times in different areas of their visual field.Because many of these patients have hemiplegia that interferes with their ability to quickly press the horn button as requested, we also measured the latency of their saccades that were directed towards the pedestrian hazards.
Seven hemianopic patients (ages 15 y.o. to 24; hemianopia onset perinatal to 17) were tested for their ability to detect pedestrians in a driving simulator. Pedestrians represented potential collisions and could appear within the blind, seeing, or expanded visual field. Dichoptic visual fields were measuredand standard clinical tests were used. Suppression was measured using standard clinical tests and an in-house developed anaglyph system. Eyetracking in the driving simulator was measured using SmartEye video eyetracker.
Average of median honk times (2.2 sec) were more than twice as long as saccade latencies (1.0 s), F(1,4) = 34.18, p=0.004. The effect of seeing vs expanded hemifield was not significant.
Button press responses appear to greatly overestimate the detection latencies for this population of patients with hemianopia. Response and saccade latency times for seeing and expanded visual fields are similar.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
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