Myopia ups risk of glaucoma

Individuals with myopia are at increased risk of developing glaucoma, with a steeper risk increase observed among those with higher-degree myopia, according to the results of a meta-analysis.

Researchers searched multiple online databases for population-based studies reporting myopia as covariate and open-angle glaucoma (OAG). The initial search yielded 1,595 articles, of which 24 were included in the meta-analysis.

The total study population comprised 514,265 individuals, and the studies had been conducted in 11 countries including the US, India, China, Japan, South Korea, Australia, Singapore, Myanmar, Sri Lanka, Greece, and Barbados.

Myopia was stratified into the following categories, based on spherical equivalent (SE) refractive error: low, moderate, moderate-to-high, and high degree. Thirteen studies defined myopia based on an SE refractive error of −0.5 dioptre (D), while seven others reported myopia of SE less than −1.0 D.

Pooled data showed that myopia of any category was associated with a higher likelihood of OAG (odds ratio [OR], 1.88, 95 percent confidence interval [CI], 1.66–2.13; I², 53 percent). The risk of OAG associated with myopia was similar in subgroups defined by ethnicity (Asians vs Westerners; p=0.80) or geographic areas (p=0.06).

The increase in the odds of OAG was commensurate with the degree of myopia (low: OR, 1.50, 95 percent CI, 1.29–1.76; moderate: OR, 1.69, 95 percent CI, 1.33–2.15; moderate-to-high: OR, 2.27, 95 percent CI, 1.74–2.96; high: OR, 4.14, 95 percent CI, 2.57–6.69).

According to the dose-response meta-analysis, each unit (1-D) increase in myopia was associated with a 21-percent increase in the risk of OAG (OR, 1.21, 95 percent CI, 1.15–1.28).

The findings underscore the importance of increased awareness of the risk of glaucoma among individuals with myopia, regardless of its degree. Importantly, more vigilant monitoring is needed among patients with myopia worse than −6 D, given the steeply increasing risk incurred in high-degree myopia.