Accommodative and Vergence Responses to a Moving Stimulus in Concussion

Area of Science:

• Neuroscience
• Ophthalmology
• Pediatrics

Background:

• Adolescent concussion frequently causes visual symptoms, especially with moving stimuli.
• The underlying mechanisms of associated oculomotor deficits are not fully understood.

Purpose of the Study:

• To objectively measure accommodative and vergence responses to a moving target in concussed adolescents and healthy controls.
• To investigate the role of disparity and blur cues in visual responses post-concussion.

Main Methods:

• Participants included 32 concussed adolescents and 32 controls.
• Eye movements (accommodation and vergence) were recorded using PowerRef 3 during binocular and monocular viewing of a moving target.
• Fourier analysis assessed response amplitudes at 0.1 Hz.

Main Results:

• Both groups showed higher responses in binocular conditions compared to monocular.
• Concussed participants exhibited significantly reduced monocular accommodative responses compared to controls.
• No significant group differences were found in vergence responses.

Conclusions:

• Accommodative and vergence responses rely heavily on disparity cues for both concussed and control groups.
• Concussed adolescents demonstrate mild accommodative deficits in monocular viewing conditions, suggesting issues in the absence of disparity cues.