Abstract
Purpose :
The impact over visual tasks of a simulated central scotoma in healthy subjects overcomes interfering complications associated with retinal diseases or aging. Patients with age-related macular degeneration (AMD), do not benefit from a head-unrestrained viewing in a smooth pursuit task. The current study investigates the role of a head-unrestrained setting over a simulated and enhanced scotoma applied to healthy participants in a smooth-pursuit task to look for similar head-movement strategies.
Methods :
Participants were asked to pursuit a moving target with unrestricted head movement while playing a 2D Pong game in VR. The moving target consisted of a 3° ball moving with an average velocity of 21.74°/s (SD: ±0.63) from one side to the other of the screen following a randomised triangular trajectory. The subjects controlled both paddles to keep the moving ball inside the playing area. Five participants were tested in 3 conditions: normal, scotoma, and augmented scotoma simulation. In the 2nd condition, eye-tracking was used to simulate a 12° circular scotoma occluding the central visual field (VF). In the 3rd condition, a 2° circular augmentation, with a diameter of 27° was implemented around the simulated scotoma. Figure 1 shows an example of a target trajectory in the 3rd condition. Each condition was tested for 15 minutes within 5 min blocks. Head velocity was calculated as the head position vector's velocity changes across subsequent frames. Velocity was averaged across each condition for each subject. A Kruskal–Wallis test investigated the effect of condition type over median head velocity.
Results :
Individuals with no simulation, simulated and augmented simulated scotoma have similar head velocities with no effect across the three conditions over the head movement strategy, χ2(2) = 0.38, p = .83.
Conclusions :
As previous studies using patients showed, head velocity was not affected in head-unrestrained VR gaming smooth pursuit task in normal, scotoma simulated, and augmented simulated scotoma conditions. The congruence of the results with the literature indicates that these new VR simulations can be further utilised to investigate oculomotor control under common eye disorders for future patient use.
This is a 2021 ARVO Annual Meeting abstract.