Higher Water Intake May Be Linked to Greater Risk of Dry Eye Disease

Jelle Vehof, MD

High intake of water was not associated with a reduced risk of dry eye disease (DED), according to new findings from a large, population-based study.

In fact, higher water intake appeared to be linked to a slightly higher prevalence of DED and DED-related symptoms according to the data.

“Based on these findings, advising dry eye patients to increase water intake is not justifiable,” wrote study author Jelle Vehof, MD, Department of Ophthalmology, University of Groningen, University Medical Center Groningen. “To fully understand any effect of water consumption on dry eye, future interventional studies should be conducted.”

Determining modifiable risk factors and interventions that help prevalent DED development may lessen the burden of the disease. It has been linked to substantial reductions in quality of life and yields a significant economic burden, with hard to treat symptoms.

Clinicians may recommend drinking more water to alleviate DED symptoms, but there is a lack of research assessing the effect of water intake on ocular surface health. Vehof and colleagues hypothesized that greater intake is associated with lower risk of DED.

The current study included participants from the population-based Lifelines cohort study, which examined health-related behaviors in those living in the north of the Netherlands (n = 167,729).

Investigators assessed DED using the Women’s Health Study (WHS) dry eye questionnaire as the main outcome. The frequently-used questionnaire asks questions including “How often do your eyes feel dry (not wet enough)?”, “How often do your eyes feel irritated?”, and “Have you ever received a diagnosis of dry eye?”.

Meanwhile, a food frequency questionnaire calculated total water intake stemming from beverages consumed, foods ingested, and the metabolic breakdown of the ingested macronutrients and alcohol. Investigators additionally calculated 24-h urine volume to provide information about the acute hydration status of the patient and validate the questionnaire’s findings.

From the Lifelines population, 51,551 individuals had available data and were thus included in the study. The prevalence of WHS-defined DED was 9.1% and were more likely to occur in females than males. Mean total water intake was 2491 ml/day, with beverage water contributing 62% of total water consumed with trest made up of food water (28%) and metabolic water (10%).

The data show a greater water intake was tied to a higher risk of having WHS-defined DED in all analyses. After correcting for comorbidities and medications, the odds ratio (OR) or having DED was 1.011 per 100 ml/day (95% confidence interval [CI], 1.004 - 1.017; P = .003).

Then, after adjustments for all comorbidities and medications, each 100 ml of urine volume increased the risk of having WHS-defined DED with around 1% (OR: 1.010 per 100 ml/day; 95% CI, 1.005 - 1.015; P <.001).

Excluding participants with report clinical diagnosis of DED still revealed higher total water intake was associated with increased odds of having symptomatic DED in all models (OR, 1.010 per 100 ml/day; 95% CI, 1.006 - 1.1015; P <.001).

The study, “The relationship between habitual water intake and dry eye disease,” was published in Acta Ophthalmologica.