The influence of age on adaptation of disparity vergence and phoria

Document Type

Article

Publication Date

4-1-2017

Abstract

A paucity of research exists to investigate whether the normal aging process influences the ability to adapt disparity vergence and phoria. Vergence eye movements and dissociated phoria were recorded from 49 healthy subjects (ages 20–70 years) using an objective eye movement tracking system. Four-degree vergence responses were modified using a double-step protocol. Dynamics of vergence were quantified via peak velocity. The phoria adaptation experiment measured the magnitude (net change in phoria level) and rate (magnitude divided by the time constant) of phoria adaption during 5 min of sustained fixation on a binocular target (40 cm/8.44° from midline). The magnitude of phoria adaptation decreased as a function of age (r = −0.33; p = 0.04). The ability to adapt vergence peak velocity and the rate of phoria adaptation showed no significant age-related influence (p > 0.05). The data suggest that the ability to modify the disparity vergence system and the rate of phoria adaptation are not dependent on age; whereas, the magnitude of phoria adaptation decreases as part of the normal adult aging process. These results have clinical and basic science implications because one should consider age when assessing the changes in the magnitude of phoria adaptation which can be abnormal in those with oculomotor dysfunctions.

Identifier

85012982048 (Scopus)

Publication Title

Vision Research

External Full Text Location

https://doi.org/10.1016/j.visres.2017.01.002

e-ISSN

18785646

ISSN

00426989

PubMed ID

28192091

First Page

1

Last Page

11

Volume

133

Grant

MRI CBET 1428425

Fund Ref

National Science Foundation

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