Abstract
Purpose: :
Purpose: To use an accelerometer device to determine if, and to what extent, glaucomatous visual field damage leads to restriction of physical activity over 1 week of normal activity.
Methods: :
Methods: Control subjects without significant vision or visual field (VF) loss, and patients with established perimetric glaucoma in both eyes wore an accelerometer device during all waking hours over one week. All patients were between ages 60 and 80. Accelerometer data were abstracted to quantify daily physical activity in terms of steps. Questionnaires were administered to evaluate relevant covariates, including age, gender, race, education, cognitive ability, and comorbid illness.
Results: :
Results: Between July 2009 and November 2010, 37 controls subjects and 65 glaucoma subjects were enrolled. Subjects had an average of 6.8 days of valid accelerometer data. The median steps per day for the control and glaucoma groups were 5,510 (IQR=3,455-7,454) and 5,137 (IQR=3,012-6,881) respectively. Within glaucoma patients, median steps per day were 5,141 (IQR=3,499-7,819), 5,616 (IQR=3,158-6,399) and 4,794 (IQR=2,447-6,497) for patients with mild, moderate and severe VF damage respectively. A 5dB drop in the better eye VF mean deviation (MD) was associated with a 12% decrease in the number of steps taken per day in a univariate analyses (p=0.049, 95% CI: 0-25%). In a multivariable model, MD remained a significant predictor of steps per day, with a 12% reduction in the number of daily steps per every 5dB worsening in the better eye VF (p=0.011, CI: 3- 20%). Education (9% more steps per additional year, p=0.003, CI: 3-15%) and comorbid illness (13% less steps per additional comorbidity, p= 0.063, 95% CI: -1-24%) were independent predictors of physical activity.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • clinical (human) or epidemiologic studies: risk factor assessment • visual fields