Maintaining a moderate BMI, having breakfast, avoiding late dinner, limiting alcohol intake and exercising regularly were associated with a reduced risk of glaucoma. Photo: Getty Images.

Beyond the impact of medical and surgical interventions, just how much control can glaucoma patients and suspects exert over the course of the disease? Although lifestyle habits may represent modifiable risk factors in glaucoma, the association between the two is not well understood. Researchers recently investigated this and found that starting the day with breakfast, avoiding late meals, limiting alcohol intake and maintaining a moderate BMI reduce the risk of glaucoma.

Over three million participants who underwent health check-ups from 2005 to 2020 in Japan were included, with 39,975 developing glaucoma during the mean follow-up of 2,058 days. Regression analyses were performed and included variables of lifestyle (BMI, current smoking, frequency and amount of alcohol consumption, eating habits, exercise habits and quality of sleep), age, sex, hypertension, diabetes and dyslipidemia.

Obesity significantly increased the risk of glaucoma. The same results have been shown in previous studies, as well as some reporting obesity actually reduces the risk of glaucoma.

“These conflicting results between studies were attributed to different sociodemographic characteristics of the study population, different definitions of obesity and multiple metabolisms, such as insulin resistance, involved in the obesity spectrum,” the authors explained. “Our results of overweight/obesity were similar to those in Korea and different from those in the Netherlands, in the United States and those of African Americans. Therefore, we speculate that staying non-obese would work positively to prevent glaucoma for Asian individuals. We presume that the inconsistent association between obesity and glaucoma among the studies was partly owing to the different subtypes of glaucoma prevalent in each population.”

Skipping breakfast and having a late dinner were significantly associated with an increased risk of glaucoma, most likely due to elevated blood pressure and blood glucose levels, both risk factors for glaucoma. Late dinner was more associated with an increased risk in females compared with males.

With alcohol use, it’s been demonstrated that intraocular pressure peaks at night, meaning that daily intake of alcohol in the evening may help reduce this peak, resulting in the prevention of the development of glaucoma, the authors suggest. “On the other hand, daily volume of alcohol consumption more than 180ml (2.5 units) a day was associated with increased risk of glaucoma compared with less than 180ml a day,” the authors noted. “Our results were similar to a recent analysis of the UK Biobank that reported that regular drinkers with a greater quantity of alcohol intake demonstrated a higher prevalence of glaucoma in a dose-dependent manner.”

Exercising for more than 30 minutes twice a week was significantly associated with lower risk, whereas walking for more than one hour every day was significantly associated with a higher risk. The authors suggest that moderate intensity exercise—not excessive exercise—could be considered ideal. “Our results suggest that one hour of daily walking may be excessive and 30 minutes of exercise twice a week may be considered moderate,” they explained.

Being underweight was associated with a significantly increased risk of glaucoma only in females. “Underweight females have less adipose tissue, which is the major place of estrogen production especially for postmenopausal women,” the authors explained. “Recently, activation of G protein-coupled estrogen receptors exhibited neuroprotective effects against retinal ganglion cell degeneration. Thus, we speculate that insufficient plasma estrogen in underweight females could result in retinal ganglion cell degeneration, which is known to play a key role in the pathogenesis of glaucoma.”

The authors suggest these results may be useful for promoting the prophylaxis of glaucoma.

Fujita A, Hashimoto Y, Matsui H, et al. Association between lifestyle habits and glaucoma incidence: a retrospective cohort study. Eye (Lond). April 19, 2023. [Epub ahead of print].