Bilateral vestibulopathy and age: experimental considerations for testing dynamic visual acuity on a treadmill

Area of Science:

• Neurology
• Ophthalmology
• Vestibular System

Background:

• Bilateral vestibulopathy (BVP) impairs dynamic visual acuity (DVA), affecting tasks like walking.
• Age may also influence DVA and test completion rates.

Purpose of the Study:

• To investigate the influence of age and BVP on DVA and test drop-out rates during treadmill walking.
• To assess the relationship between walking speed, DVA loss, and drop-out rates.

Main Methods:

• 44 BVP patients and 63 healthy subjects performed DVA tests on a treadmill at speeds of 0, 2, 4, and 6 km/h.
• Dynamic visual acuity loss was calculated as the difference between static and dynamic visual acuity.
• The impact of BVP and age on drop-out rate and DVA loss was analyzed.

Main Results:

• Both age and BVP significantly increased the drop-out rate (p ≤ 0.038).
• BVP patients showed significantly higher DVA loss across all speeds (p < 0.001).
• Age did not affect DVA loss, but higher walking speeds increased DVA loss in BVP patients (p ≤ 0.036).

Conclusions:

• Treadmill DVA testing is a functional measure of vestibular function, showing significant loss in BVP.
• Age and BVP increase drop-out rates at faster speeds, necessitating age-matched controls.
• Consider individual preferred walking speeds and limit speeds for older adults in DVA testing.