Purchase this article with an account.
Rakie Cham, Mark S Redfern, Caitlin O'Connell, Ian P Conner, Gadi Wollstein, Kevin C Chan; Sensory Integration Abilities for Balance in Glaucoma. Invest. Ophthalmol. Vis. Sci. 2020;61(7):917.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Falls risk increases with glaucoma. The inability to see obstacles such as steps or stairs is one mechanism of falls. Another potential mechanism is reduced postural control. The impact of glaucoma on the ability to centrally integrate sensory information relevant for balance has not been systematically investigated. The goal of this study is to assess the influence of glaucoma severity on sensory integration abilities for balance.
Eleven adults diagnosed with glaucoma were recruited. Glaucoma severity was determined using two measures: (1) a functional measure, specifically visual field mean deviation (MD) assessed by automated Humphrey perimetry and (2) a structural measure, specifically retinal nerve fiber layer (RNFL) thickness as measured by OCT. Standing balance was assessed using an adapted version of the Sensory Organization Test (SOT) that probes the ability to integrate visual, somatosensory and vestibular information for balance control (Nashner, 1997). The six SOT postural conditions were used, each lasting 3 min. Underfoot center of pressure was used to compute sway speed. Statistical analyses consisted of mixed linear models performed within each postural condition, with glaucoma severity as a fixed effect and subject as the random effect. The dependent measure was sway speed. Statistical significance was set at 0.05.
A worse visual field deficit, as reflected by MD, in the better eye was associated with increased sway speed in the first four SOT conditions (p<0.05), i.e. conditions involving altered or absent visual OR somatosensory information. This effect was not found in conditions when the postural control system relies solely on the vestibular system to maintain balance (SOT Conditions 5-6, p>0.2). Visual field deficits in the worse eye and structural damage in either eye, as reflected by RNFL thickness, were not associated with sway speed under any of the postural conditions.
Balance is impacted by glaucoma under conditions where sensory integration is challenged. Interestingly, visual field severity and sway speed were associated even during the eyes closed condition. This may suggest a central sensory integration mechanism. Further research is warranted. Reference.Nashner, L. M. (1997). Computerized Dynamic Posturography. In G. P. Jacobson, et al. (Eds.), Handbook of balance function testing. San Diego, CA: Singular Publishing Group, Inc.
This is a 2020 ARVO Annual Meeting abstract.
This PDF is available to Subscribers Only