Eye dryness, itchiness can go away with a bout of physical activity

For individuals with dry and itchy eye complaints, engaging in aerobic exercise can bring major relief, a study has found.

“With so much of our activity tied to screen usage, dry eye symptoms are becoming increasingly common,” according to Heinz Otchere, study co-author and a PhD candidate in vision science at the University of Waterloo in Canada. “Instead of having to use eye drops or other alternative treatments, our study aimed to determine if remaining physically active can be an effective preventative measure against dryness.”

The study included 52 university students aged 18–25 years who were athletes (n=26, mean age 22.4 years, 50 percent male) or nonathletes (n=26, mean age 21.8 years, 65.4 percent male). They underwent an aerobic exercise session using a treadmill, following the Bruce treadmill test protocol until exhaustion. Athletes exercised at least five times per week, while nonathletes did only once per week.

Otchere and colleagues performed visual examinations prior to and after the exercise regimen. They measured distance visual acuity (VA), stereopsis, noninvasive tear break-up time (TBUT), and phenol red thread test.

At baseline, the athletes had much higher TBUT than nonathletes (mean, 14.6 vs 11.9 s; p=0.021). No significant between-group differences were observed in other ocular measurements.

Following exercise, tear secretion improved for the athletes, with the mean basal tear secretion increasing from 22.3 mm to 25.8 mm (p<0.001). Meanwhile, the nonathletes showed only a borderline increase in tear secretion, from 21.42 mm to 23.73 mm (p=0.08). The athletes also showed a more favourable improvement in TBUT compared with nonathletes (mean, 17.7 vs 14.8 s; p=0.004). [Exp Eye Res 2022;214:108865]

With regard to other outcomes, exercise improved the VA without significant between-group difference, whereas stereoacuity remained unchanged after exercise in either group. Gender did not influence the differences in tear function measures between athletes and nonathletes after exercise. On the other hand, the duration of exercise exerted a borderline effect on the tear film stability (p=0.068) after exercise.

Blinking covers the eyes in tear film, an essential protective coating necessary for maintaining healthy ocular function, Otchere noted. When there is tear film instability, the ocular surface can develop dry spots, causing symptoms such as itchiness or stinging and burning sensations.

“Our findings support the differential effect of maximal incremental treadmill exercise on tear secretion and tear film stability between athletes and nonathletes. Thus, increased physical fitness and the duration of exercise might be crucial in the improvement of tear function through aerobic exercise,” according to the authors.

“It can be challenging for people to regularly exercise when the demand is there to work increasingly longer hours in front of screens,” Otchere said. “However, our findings show physical activity can be really important for not just our overall wellbeing, but for our ocular health too.”