Medical researchers in Australia have found a link between normal-tension glaucoma and an increased risk of developing dementia, according to a new study published in the British Journal of Ophthalmology. The disease pathway for normal-tension glaucoma is not fully understood, but the study authors say their findings suggest that it may share neurodegenerative pathways with dementia.

Lead author Sean Mullany, MD, from Flinders University in Australia examined 2 previous multiethnic studies that showed a link between primary open-angle glaucoma and dementia, and this led the authors to question whether specifically normal-tension glaucoma is linked to cognitive impairment and dementia.

"Cognitive impairment was found to be more than twice as prevalent in patients with normal-tension glaucoma than it was in those with high-tension glaucoma,” said Dr. Mullany. “Our finding of an association between this type of glaucoma and cognitive impairment supports a growing body of evidence suggesting an association between glaucoma and dementia.”

The researchers used the Australian and New Zealand Registry of Advanced Glaucoma to randomly select 248 patients aged at least 65 years old who had normal-tension glaucoma, and these were matched by age and sex with 349 patients with high-tension glaucoma.