Abstract
Purpose :
Vection is the illusory sensation of self-motion, and is largely driven by peripheral vision. Previously, our lab demonstrated that vection responses are either weaker or absent in patients with mild glaucoma. The purpose of this study is to determine whether virtual reality (Oculus Rift™ system) can display a vection stimulus that induces powerful vection responses in both healthy controls and patients with glaucoma. We hypothesize that although patients with mild glaucoma take longer to experience vection, the Oculus Rift will be able to induce strong vection responses in this population.
Methods :
Seventeen patients with mild, bilateral glaucoma (mean age 70.3 ±5 years) and sixteen controls with healthy vision (mean age 60.4 ±9 years) participated. The circular vection test used a random dot pattern projected on the Oculus Rift viewer. The dots rotated left to right at a velocity of 20deg/s (slow) or 40deg/s (fast). Participants viewed the stimuli monocularly for 2 minutes in each condition, and vection latency and duration were measured using a button-response box. After each condition, participants reported how strongly they felt vection, on a 1-10 scale.
Results :
There was no vection response in both conditions for 5 of 17 patients (29%) and 2 of 16 controls (13%). 2 x 2 mixed factorial ANOVAs showed that vection latency was significantly shorter for the control than for the glaucoma group (F(1,22) = 6.38, p = .019), but there was no significant difference between groups for vection duration or reported vection strength. Also, there was a significant main effect of stimulus velocity only on vection latency: mean vection latency was significantly shorter in the fast than in the slow condition (F(1,22) = 5.99, p = .023).
Conclusions :
Our preliminary data suggest that the Oculus Rift can produce vection responses in both patients with mild glaucoma and controls. However, fewer patients with glaucoma experience vection, and their vection latencies were longer. Despite this, patients with glaucoma still rate their vection strength similarly to controls. The Oculus Rift appears to be a viable new tool for studying vection—even in some patients with compromised peripheral vision.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.