3D Virtual Environment Human Navigation Task in Glaucoma

Abstract

Purpose : To evaluate navigational abilities and spatial cognition in patients with glaucoma using a virtual-reality environment, the Virtual Environment Human Navigation Task (VE-HuNT).

Methods : The VE-HuNT is a CAVE immersive virtual reality environment consisting of 3 vertically-oriented 4K 80-inch 3D LED Screens, with 3 screens aligned at a 135° configuration. Software developed in-house creates spatial displays that simulate approximately 150° of a person’s field of view. Patients wear polarizing glasses to discern a 3D image during testing and navigate through the virtual environment using a steering wheel and an accelerator pedal. In the present study, navigational abilities were investigated in glaucoma patients and control subjects by performing way-finding tasks in different square virtual rooms with different arrangements of visual cues, such as colored walls and 3D objects (chair, potted plant). Subjects were initially instructed to drive to a clearly indicated location in each virtual room. Subsequent trials were conducted requiring the patient to revisit the initial location, which was no longer visibly marked but reappeared when the subject drove within a defined short distance. Trials are repeated with the subject starting from different starting points. Subjects showed no evidence of cognitive impairment as assessed by the Montreal Cognitive Assessment Test(MoCA).

Results : 135 trials were conducted in a pilot investigation of 3 subjects with bilateral glaucomatous visual field loss and 3 controls. Glaucoma subjects performed significantly slower than control subjects in the way-finding task requiring integration of multiple spatial cues (47.7 ± 37.5s vs. 14.9 ± 8.5s; P=0.005; GEE model adjusting for multiple correlated observations). The average path length to target was significantly longer in glaucomatous subjects than controls (9.5 ± 7.3m vs. 5.7 ± 1.7m; P=0.05; GEE model). No significant differences between glaucoma and controls were seen in the environments that had orientation landmarks not requiring integration of multiple spatial cues.

Conclusions : Glaucomatous visual field loss was associated with increased time in completing certain navigational tasks performed on a virtual reality environment. The VE-HuNT system may serve as a tool for investigation of navigational abilities and spatial cognition in subjects with impaired vision and to distinguish their deficits with those of patients with impaired spatial cognition.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.