Abstract
Purpose :
To identify, as part of a cross-sectional, case-control study, gait characteristics in AMD patients that may put them at a higher risk for mobility difficulty and increased falls than visually normal controls.
Methods :
Twenty-nine patients with AMD and 20 controls without AMD, all between the ages of 65 and 90 years and walking without any mobility devices, were recruited from the Wilmer Eye Institute, Johns Hopkins. The GAITRite electronic walkway was used to collect temporal and spatial gait parameters. Multiple linear regression models were utilized to assess association between gait parameters and AMD status after controlling for age, gender, and body mass index (BMI). For each measure, gait variability was judged via the inter-stride coefficient of variation value.
Results :
Study participants were predominantly white (86%) and the majority were female (55%). Mean age of the full study population was 73.51 (SD: 8.14) years, while mean BMI was 27.80 (SD: 5.44) kg/m2. Median better-eye acuity (logMAR) was 0.23 (IQR=0.18, 0.36) and -0.02 (-0.08, 0.02) for the AMD and control groups (p=0.00), respectively, while median binocular logCS values were 1.44 (IQR=1.32, 1.56) and 1.76 (1.76, 1.80) (p=0.00). In regression models, AMD patients had significantly slower walking speeds (β= -11.79 cm/sec, 95% CI = -22.87, -0.72, p=0.037) and stride velocity (β= -11.92 cm/sec, 95% CI = -23.10, -0.73, p=0.037) as compared to controls. AMD was also associated with greater variability in stride length (β= -1.24 %, 95% CI = -2.26, -0.23, p=0.018) and stride velocity (β= -1.95 %, 95% CI = -3.61, -0.28, p=0.023) as compared to controls. There were no group differences in base of support, step length, and stride length, or variability in base of support and step length.
Conclusions :
When compared to controls, AMD patients have significantly slower walking speeds and exhibited greater gait variability. Each of these gait parameters has been previously associated with a greater risk of fall, suggesting that these gait characteristics may contribute to mobility issues and falls in patients with AMD.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.