NOV 28, 2018
Glaucoma
This longitudinal, observational study assessed the association between physical activity and rate of visual field loss in patients with glaucoma.
Study design
Researchers recruited 141 patients (mean age 65 years) with suspect or manifest glaucoma; each participant wore accelerometers for 1 week to define the level of physical activity. The assessment included average steps per day, minutes of moderate-to-vigorous activity and minutes of nonsedentary activity. Multivariate analysis was performed to identify factors associated with rates of visual field loss.
Outcomes
At baseline, the eye mean deviation was -6.6 dB and average steps per day was 5,613 steps/day. The unadjusted average rate of vision loss was 0.36 dB/year.
Multivariable analysis revealed that visual field loss was significantly slower in patients who demonstrated more steps and moderate-to-vigorous activity (both P<0.001). More nonsedentary activity also reduced progression of visual field loss (P=0.005). An additional 5,000 steps or 2.6 hours of nonsedentary activity reduced the average rate of loss by approximately 10%. Older age, non-white race, glaucoma or cataract surgery and moderate baseline vision field damage (-6dB ≥ MD > -12dB) was associated with increased rates of visual field loss.
Limitations
There are multiple potential confounding factors to the study findings, such as socioeconomic levels, patient health awareness, medication adherence, overall health behaviors and other comorbidities. The use of accelerometers as a surrogate for physical activity is also limited because it cannot capture all forms of physical exercise or provide contextual information on the type and purpose of activity.
Clinical significance
In this study, physical activity correlated with a decrease in visual field progression in patients being treated for glaucoma. If this association is validated in further prospective studies, it would present a novel modifiable risk factor that could help prevent progressive glaucoma damage.