Purchase this article with an account.
Fuensanta A Vera-Diaz, Ronalie Baldovino, Peter J Bex; Effect of target depth and field of view in dynamic accommodation and vergence responses of myopes and emmetropes. Invest. Ophthalmol. Vis. Sci. 2020;61(7):543.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Peripheral and binocular visual function play a key role in myopia. We examine how field of view and target depth affect the dynamic accommodation and vergence responses in young adults with emmetropia or myopia.
Dynamic accommodation responses (WAM-5500) and binocular eye position (Pupil Labs eye tracker) to sinusoidally moving stimuli from 1 to 4D over a cycle of 9 sec were simultaneously measured. Reponses were evaluated for three types of stimuli in random order: a real object (RO), a 3D stereoscopic image of the object (3D), and a flat 2D image of the object (2D). Measurements were taken under a free space (FS) condition and also a constricted field of vision (FOV) subtending 9°. Participants were young adults with emmetropia (n=12, SE: 0.27±0.35D) or myopia (n=18, SE: -2.80±0.35D). We fit the accommodation (OS monocular) and vergence raw data to sinusoids with amplitude and phase (latency) as free parameters. Mixed linear models were designed to evaluate the effect of stimuli on the responses’ amplitude and phase.
Mixed model analyses showed a significant main interaction of condition and refractive group on accommodation amplitude (p<0.01, η2=0.16). Smaller accommodation responses were found for RO compared to 3D and 2D conditions in myopes only (p<0.01). Emmetropes, not myopes, showed smaller amplitudes for the FOV conditions, reaching significance for 3D FOV (p=0.02). These effects are a consequence of differences in the closest (4D) stimuli (F=30.46, P<0.01). No effect of condition or refractive group was found in the accommodation phase shifts, with a trend for larger phase shifts in the FOV conditions. A stimulus condition by group effect interaction was also found on convergence amplitude (p =0.01, η2 =0.12). Convergence responses were smaller for the RO FOV condition compared to the 2D and 3D conditions (FS or FOV) (p<0.01) for all subjects, with myopes converging less than emmetropes for this condition (F=7.25, p=0.01) and more for 2D FS (F=4.57, p=0.04). No effect of condition or refractive group was found in phase shifts in convergence.
Stimulus depth and field of view size affect accommodation and vergence responses differently in myopes and emmetropes. Myopes responses for 2D and 3D stimuli are larger than emmetropes. Accommodation responses are affected by changes in the stimuli field of view in emmetropes, but not in myopes.
This is a 2020 ARVO Annual Meeting abstract.
This PDF is available to Subscribers Only