New York, Aug 7 (IANS) Lower blood manganese level and higher blood mercury level may increase risk of glaucoma, the leading cause of irreversible blindness worldwide, says a new study.

Abnormal body levels of essential elements and exposure to toxic trace metals have been postulated to contribute to the pathogenesis of diseases affecting many organ systems, including the eye, according to background information in the article.

Shan Lin of University of California, San Francisco in the US, and colleagues investigated the relationship between body levels of five trace metals (manganese, mercury, lead, cadmium, and arsenic) and the prevalence of glaucoma.

Researchers analysed data from 2,680 individuals (19 years and older) participating in the fourth Korea National Health and Nutrition Examination Survey between January 2008 and December 2009.

Analyses indicated that lower blood manganese levels and higher blood mercury levels were associated with greater glaucoma prevalence.

No association was found between blood lead or cadmium levels or urine arsenic levels and a diagnosis of glaucoma in the study population.

The study published online in the journal JAMA Ophthalmology.