The effect of vision impairment on balance and posture of older adults: Simulated versus Real Vision Impairment

Abstract

Purpose : The Nintendo Wii Balance Board is an accurate and reliable tool to measure balance in a clinical setting. One issue with this is that we do not know what the baseline balance capability of an individual is before the onset of visual impairment. Thus, the increased variance in postural control due to vision loss cannot be separated from fall risk. One solution to this confound is to use simulated impairment goggles that replicate the loss of acuity that occurs with onset of vision loss. Therefore, the current study aimed to examine the impact of simulated vision impairment on balance and postural stability in community-dwelling older adults, and compare it to older adults with vision impairment.

Methods : Participants with normal, healthy vision were recruited through community-based events targeting older adults. Individuals diagnosed with a vision impairment (VIPs) were recruited from the Concordia Retinal Image Database. Fear of falling was assessed using the Activities-specific Balance Confidence (ABC) Scale. All participants performed the Timed Up and Go (TUG) with their normal correction. Participants with healthy vision also performed the TUG while wearing goggles simulating vision impairment (visual acuity 20/80, or 20/200). Normal correction and simulated impairment conditions were counterbalanced.

Results : Preliminary results show that the number of falls in the past year did not significantly differ between individuals with vision impairment (N = 31), and those with normal vision (N= 43). However, fear of falling did, F (1,68) = 9.62, p = 0.003. A Cohen's effect size value (d = 0.816) suggests a large effect size, even when controlling for age. The TUG times significantly differed between VIPs and controls, F(1, 69) = 10.61, p = 0.002, even in simulated impairment F(1,68) = 9.62, p = 0.003, as did total displacement recorded by the Wii (VIPs v. Controls: F(1, 66) = 25.56, p < 0.001; VIPs v. simulated impairment F(1, 68) = 15.17, p < 0.001.

Conclusions : VIPs have poorer postural control than older adults with vision corrected to 20/20, even in simulated vision impairment conditions. This indicates that there are additional factors contributing to decreased postural control in VIPs, besides decreased visual acuity and contrast sensitivity. The significant difference in the results of the ABC scale suggest fear of falling is a factor that merits further study.

This is a 2020 ARVO Annual Meeting abstract.