Physical activity reduces glaucoma risk
MedWire News: Adopting a more active lifestyle may help improve low ocular perfusion pressure levels, thereby tackling a major risk factor for glaucoma, say researchers.
Ocular perfusion pressure (OPP) is the difference between arterial blood pressure (BP) and intraocular pressure (IOP). It is therefore thought that factors known to affect BP, such as exercise, are likely to affect OPP.
Jennifer Yip (University of Cambridge, UK) and colleagues examined the link between previous physical activity and current OPP in 2512 men and 3138 women, aged 48 to 89 years. Their results are published in the journal Investigative Ophthalmology and Visual Science.
Using a detailed questionnaire taken at baseline (1993-1997), the participants were classed as inactive, moderately inactive, moderately active, or active.
The researchers found that this self-assessed activity level was associated with eye pressure measurements taken at eye examinations from 2006 through 2010. Moderate physical exercise was associated with a 25% reduction in the risk for low OPP, after adjusting for age, gender and other confounding factors.
"It appears that OPP is largely determined by cardiovascular fitness," commented Paul Foster (University College London Institute of Ophthalmolgy), one of the study authors, in a press release. "We cannot comment on the cause, but there is certainly an association between a sedentary lifestyle and factors which increase glaucoma risk."
The effect of physical activity on OPP was found to be independent of IOP, and largely dependent on diastolic BP. The risk for diastolic perfusion pressure was 27% lower in the active individuals compared with those that were less active.
OPP is an important determinant of ocular blood flow, and instability or dysregulation of this flow has been linked to glaucoma, explain Yip et al. "Physical activity has a protective effect on other disorders associated with dysregulation in older people, such as frailty syndrome, and similar physiologic pathways may be evident in [glaucoma]," they write.
The active study participants had 1.2 mmHg higher mean diastolic perfusion pressure than the less active individuals, which the authors describe as "small" and "may appear clinically insignificant on an individual level." But they emphasize that "small shifts in population mean values can have a significant impact on disease frequency."
Foster believes their findings hold significant value for glaucoma prevention. "Before now, the only modifiable risk factor was IOP, altered by medication, laser or surgery," he said. "We believe our study points toward a new way of reducing glaucoma risk, through maintaining an active lifestyle. This is a way that people can participate in altering their risk of glaucoma and many other serious health problems."
By Chloe McIvor