AUG 03, 2012
This novel prospective study in the June issue of Ophthalmology found that individuals with glaucoma with greater levels of visual field (VF) loss had substantial reductions in physical activity and walking. The study's authors conclude, therefore, that glaucoma patients with advanced bilateral VF loss may be at greater risk for the numerous negative outcomes associated with lower levels of physical activity.
The study included 58 glaucoma suspects without significant VF or visual acuity loss, who served as controls, and 83 glaucoma subjects with bilateral VF loss. All study participants were between 60 and 80 years old and wore an accelerometer for seven days while engaging in their normal activities.
The authors found that the median control subject engaged in 16.1 minutes of moderate or vigorous physical activity (MVPA) daily and walked 5,891 steps/day, as compared with 12.9 minutes of MVPA daily (P = 0.25) and 5,004 steps/day (P = 0.05) for the median glaucoma subject. In multivariate models, glaucoma was associated with 21 percent less MVPA (P = 0.37) and 12 percent fewer steps per day (P = 0.21) than controls, although these differences were not statistically significant. The authors note that the lack of between-group differences in MVPA may be due to the fact that glaucoma patients with mild bilateral VF loss had physical activity levels similar to or only slightly less than those of controls.
However, they found a significant dose response relating VF loss to decreased activity, with each 5 dB decrement in the VF of the better eye associated with 17 percent less MVPA (P = 0.03) and 10 percent fewer steps per day (P = 0.001). Glaucoma subjects in the most severe tertile of VF damage (better-eye VF MD worse than -13.5 dB) engaged in 66 percent less MVPA than controls (P = 0.001) and took 31 percent fewer steps per day (P = 0.001).
These results suggest that VF loss resulting from glaucoma did indeed impact physical activity. The ability to move freely and safely affects quality of life, as well as patient health, with higher levels of physical activity associated with better overall health outcomes, in addition to assisting in the control of glaucoma. The authors note that the impact of severe VF loss on physical activity and walking highlights the need for better methods to improve mobility outcomes in individuals with more advanced glaucoma.