Dual tasking and balance in those with central and peripheral vision loss.
OBJECTIVE
To investigate the effects of a secondary task on standing balance in patients with glaucoma or AMD compared with age-similar control subjects.


METHODS
Twelve AMD, 12 glaucoma, and 12 control participants underwent posturography under two standing conditions (eyes open on a firm or foam-rubber surface) and two tasks: quiet standing and undertaking a mental arithmetic task. Center of foot-pressure average displacement (root mean square [RMS]; in millimeters) was calculated.


RESULTS
The mean (SD) age of the participants in each group was as follows: controls 66.2 (6.4) years, glaucoma 69.2 (4.3) years, and AMD 72.2 (5.3) years. There were significant differences in RMS between controls and AMD patients when undertaking the mental arithmetic task standing on the firm surface (mean difference [SE]: 2.8 [0.8] mm, P = 0.005). There were significant differences between controls and AMD patients when undertaking the mental arithmetic task on the foam surface, with the difference between controls and glaucoma patients approaching significance (mean difference [SE]: control versus AMD = 3.1 [0.9] mm, P = 0.005; control versus glaucoma = 2.2 [0.9] mm, P = 0.06).


CONCLUSIONS
Postural instability increases with the addition of a secondary task in older persons, which may put them at greater risk of falls. Patients with central losses exhibit greater instability with the addition of a secondary task, particularly during somatosensory perturbations. The negative effects of secondary tasks on balance control in those with peripheral visual losses become more apparent under somatosensory perturbations.
National Institute for Health Research Biomedical Research Center for Ophthalmology, Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom.
Aachal
A
Kotecha
Reena
R
Chopra
Rachel T A
RT
Fahy
Gary S
GS
Rubin
D000368:Aged; D000375:Aging; D018450:Disease Progression; D005260:Female; D005684:Gait / Q000502:physiology*; D005901:Glaucoma / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008268:Macular Degeneration / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D004856:Postural Balance; D011187:Posture / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D015354:Vision, Low / Q000209:etiology / Q000503:physiopathology*; D014794:Visual Fields
age-related macular degeneration; balance; glaucoma; secondary task