Glaucoma-Related Differences in Gaze Behavior When Negotiating Obstacles

Abstract

PurposeSafe navigation requires avoiding objects. Visual field loss may affect how one visually samples the environment, and may thus contribute to bumping into objects and falls. We tested the hypothesis that gaze strategies and the number of collisions differ between people with glaucoma and normally sighted controls when navigating around obstacles, particularly under multitasking situations.MethodsTwenty persons with moderate–severe glaucoma and 20 normally sighted controls walked around a series of irregularly spaced vertical obstacles under the following three conditions: walking with obstacles only, walking and counting backward to simulate a conversation, and walking while performing a concurrent visual search task to simulate locating a landmark. We quantified gaze patterns and the number of obstacle contacts.ResultsCompared with controls, people with glaucoma directed gaze closer to their current position (P < 0.05). They also directed a larger proportion of fixations (in terms of number and duration) to obstacles (P < 0.05). Despite this finding, considerably more people with glaucoma contacted an obstacle (P < 0.05). Multitasking led to changes in gaze behavior in both groups, and this was accompanied by a large increase in obstacle contacts among those with glaucoma (P < 0.05).ConclusionsGlaucoma alters gaze patterns when negotiating a series of obstacles and increases the likelihood of collisions. Multitasking in this situation exacerbates these changes.Translational RelevanceUnderstanding glaucoma-related changes in gaze behavior during walking in cluttered environments may provide critical insight for orientation and mobility specialists and guide the design of gaze training interventions to improve mobility.

Mobility improvement of patients with peripheral visual field losses using novel see-through digital spectacles

“…In the walking track, lower central fixation scores without the remapping condition indicate that the patient gaze was shifted more toward nearby objects, while higher scores with the activated AR DSpecs suggested that patients were looking farther ahead. This observation was in agreement with a previous study that compared normal subjects and glaucoma patients gaze behavior in a walking test [8]. This implies that with AR DSpecs, our patients were demonstrating more normal eye movement behavior.…”

“…Mobility testing has been reported in PVFL patients [ 8 , 33 , 34 ], to assess the value of new technologies to help patients avoid collisions and assess their perceived FOV. Some implementations with AR headsets minified scene images in front of the eye, including the study by Trese and coworkers [ 9 ], however, no mobility tests were performed as we did with our device.…”

“…We built a walking track to determine if using the AR DSpecs could improve the ability of patients with PVFL to detect peripheral objects and safely navigate in an environment that mimicked daily mobility activities. The track was adapted from a study reported by Lajoie and associates to measure differences in mobility between normal and glaucoma patients [8].…”

“…The eye tracking system recorded the two trial conditions when the patient walked with AR DSpecs; with and without image remapping (two conditions of gaze data). Based on similar studies [8,26], we used the following eye gaze scores:…”

“…Lee and coworkers reported that glaucoma patients perform more saccades, although they miss peripheral objects [7]. Lajoie and associates demonstrated that glaucoma patients exhibit an altered gaze pattern compared to normal subjects, and experience more obstacle contacts [8].…”