Purchase this article with an account.
Emilie S. Chan, Chad Hochberg, Eugenio Maul, Luigi Ferrucci, David S. Friedman, Pradeep Y. Ramulu; Objective Quantification Of Physical Activity And Travel Outside The Home In Age-Related Macular Degeneration. Invest. Ophthalmol. Vis. Sci. 2011;52(14):1911.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Decreased visual acuity (VA) is associated with worse balance, falls, and greater reported mobility limitations. Here, we use tracking devices to measure physical activity and the frequency of out-of-home travel in the daily lives of subjects with age-related macular degeneration (AMD).
Control subjects with normal vision and AMD patients between 60-80 years were recruited. AMD patients had evidence of bilateral drusen, geographic atrophy, or choroidal neovascularization with bilateral VA loss to 20/32 or worse, or unilateral VA loss to 20/200 or worse. Physical activity over 1 week was monitored in terms of steps with an accelerometer. Out-of-home travel was monitored with a cellular network based tracking device.
37 controls and 28 AMD patients provided an average of 6.7 +/- 1.0 days of complete tracking data. Controls were younger than AMD subjects (69.9 vs. 74.1 years, p=.002) and more often non-white (p=.005). No group differences were found in gender, education, employment, cognition, or comorbid illnesses (all p>.2). Mean logMAR VA in the better eye was 0.04 +/- 0.12 for controls and 0.51 +/- 0.43 for AMD patients (p<.001).The median control subject walked 5,510 steps/day (IQR=3,455 to 7,454) while the median AMD subject walked 3,085 steps/day (IQR=2,011 to 6,096). In multivariable models, AMD patients with a better-eye VA less than 20/60 walked 43% less than controls (p=0.046), and each one-line drop in VA was associated with a 6.1% decrease in daily steps (95% CI: 0 to 12%, p=0.043). AMD patients were significantly more likely to be in the lowest tertile of daily steps taken (OR=5.8 for taking under 2930 steps/day; p=.037; 95% CI: 1.1 to 30.7).With regards to travel outside the home, the median control subject made 1.33 excursions/day (IQR=1.00 to 1.57), while the median AMD patient made 1.00 excursions/day (IQR=0.64 to 1.31). In multivariable models, AMD patients more often made 1 or fewer excursions/day as compared to controls (OR=3.5; p=0.056; 95% CI: 0.97 to 12.7), with even higher odds noted for AMD patients with better-eye VA less than 20/60 (OR=6.8; p=0.029; 95% CI: 1.2 to 37.8).
Many AMD patients restrict physical activity to levels far below recommended guidelines and also limit travel outside the home. The substantial impact of AMD on mobility outcomes demonstrates the importance of vision-preserving treatments, and highlights the need for mobility training to help maintain adequate levels of activity.
This PDF is available to Subscribers Only