A new study of South Koreans has linked lower levels of manganese in the blood and higher mercury concentrations to a greater risk of glaucoma.

The findings, published online by JAMA Ophthalmology, suggest a previously unknown risk factor for the disease, which is the leading cause of irreversible blindness worldwide, Medical Xpress reports.

For the study, Shan C. Lin, M.D., of the University of California-San Francisco, and colleagues tracked levels of five trace metals — manganese, mercury, lead, cadmium, and arsenic — in more than 2,600 Korean adults, as well as the prevalence of glaucoma.

The results showed those with low manganese and high mercury levels most likely to be diagnosed with glaucoma.

"Future prospective investigations will be necessary to confirm these associations and to explore the role of trace elements in the pathogenesis of glaucoma, as well as possible neuroprotective effects, which could lead to novel therapeutic targets in glaucoma management," the authors wrote.