Postural stability changes during large vertical diplopia induced by prism wear in normal subjects

Area of Science:

• Neuroscience
• Human Physiology
• Vision Science

Background:

• Postural stability is crucial for daily activities.
• Visual input significantly influences postural control.
• The impact of induced diplopia on postural stability requires further investigation.

Purpose of the Study:

• To investigate the effects of induced vertical diplopia on postural stability in healthy adults.
• To determine if postural control mechanisms adapt to prolonged abnormal visual input.

Main Methods:

• 20 healthy adults participated in the study.
• Postural stability was measured using electric stabilometry.
• Participants wore 6-prism-diopter prisms inducing vertical diplopia for 60 minutes, with measurements taken at intervals.
• Measurements were recorded with eyes open and eyes closed.

Main Results:

• Postural stability, measured by sway path length, significantly improved (shortened) when eyes were closed after 60 minutes of prism wear (p < 0.05).
• No significant changes in postural stability were observed when participants' eyes were open during prism wear.
• These findings indicate differential effects of induced diplopia on postural control depending on visual input availability.

Conclusions:

• Large vertical diplopia induced by prisms does not impair postural stability when vision is available (eyes open).
• Postural stability improves with eyes closed under induced diplopia, suggesting enhanced reliance on non-visual sensory information.
• This implies that compensatory postural control mechanisms can be reinforced under conditions of non-fusible diplopia.