Raise your morning cup of joe and youll raise your intraocular pressure? Cinch up your tie too high and youll push up your IOP too high as well? Two new studies refine what we know about coffee intake, tight neckties and elevated IOP.
Coffee. Eye doctors routinely warn glaucoma patients that drinking coffee can temporarily increase IOP. But the Blue Mountains Eye Study (no relationship to Jamaica Blue Mountain coffee) found that this is not true for all glaucoma patients and suspects.1
Researchers examined 3,654 participants ages 49 and older and surveyed them about their daily intake of coffee and tea. Specifically, researchers found that participants with open-angle glaucoma (OAG) who were regular coffee drinkers had significantly higher mean IOP (19.63mm Hg) than people with OAG who didnt drink coffee (16.84mm Hg), after adjusting for age, sex and systolic blood pressure.
However, researchers found no association between coffee (or caffeine) consumption and higher IOP in participants with ocular hypertension or in those without open-angle glaucoma.
Neckties. Two years ago, researchers from the State University of New York Downstate College of Medicine concluded that a tight necktie increases IOP in both normal subjects and glaucoma patients, and that it could affect both the diagnosis and management of glaucoma.2
But a new study found that the IOP increase from a tight necktie lasts only minutes.3
Researchers in Ireland performed a random, masked study of IOP in 18 normal control subjects and 19 patients who had primary open-angle glaucoma. Three minutes after tightening the necktie, mean IOP increased slightly (0.56mm Hg) in the normal group and significantly (1.58mm Hg) in the glaucoma group. Twelve minutes later, mean IOP decreased by 0.89mm Hg in the normal group and decreased significantly by 0.94mm Hg in the glaucoma group. There was no correlation between the change in mean IOP and the patients age or collar size.
Avoidance of wearing a tight necktie over an extended period is therefore not necessary in patients with glaucoma, the researchers concluded.
1. Chandrasekaran S, Rochtchina E, Mitchell P. Effects of caffeine on intraocular pressure: the Blue Mountains Eye Study. J Glaucoma 2005 Dec;14(6):504-7.
2. Teng C, Gurses-Ozden R, Liebmann JM, et al. Effect of a tight necktie on intraocular pressure. Br J Ophthalmol 2003 Aug;87(8):946-8.
3. Talty P, OBrien PD. Does extended wear of a tight necktie cause raised intraocular pressure? J Glaucoma 2005 Dec;14(6):508-10.