A tight shirt might make some men look hunky, but adding a tight necktie might affect how they see. A new study shows that a collar or tie can pinch off blood flow and raise the pressure inside the eye--the most common risk factor for glaucoma. Constricting cravats might also worsen glaucoma or prevent a proper diagnosis.
About 3 million Americans suffer from glaucoma, the leading cause of preventable blindness in the US. In 75% of cases, high pressure in the eyes damages the optic nerve and leads to gradual loss of vision. (Although high eye pressure is the most prevalent risk factor, only 2% of people with high eye pressure go on to develop glaucoma every year.) Previous research has shown that increasing blood pressure in the head--by blowing up a blood pressure cuff around the neck or hanging a volunteer upside down by the feet, for example--can double eye pressure. Even minor activities such as holding one's breath during a glaucoma test can result in higher-than-normal readings. Ophthalmologist Robert Ritch of the New York Medical College in Valhalla and colleagues tested whether neckties can also influence eye pressure.
The researchers measured the eye pressure in 20 men with normal vision and 20 men with glaucoma before, during, and after tightening their neckties for 3 minutes. "If I can't slide my index finger between the neck and the collar, that's tight," says Ritch. The researchers found that tight neckties increased the pressure in 60% to 70% of both normal and glaucoma patients' eyes, probably by constricting the jugular vein, through which blood returns from the head to the heart. In addition, ties can skew measurements of eye pressure, confounding diagnosis and treatment, the researchers report in the 29 July British Journal of Ophthalmology.
The study points out another factor to consider when testing for glaucoma, says ophthalmologist Theodore Krupin of Northwestern University's Feinberg School of Medicine in Chicago, Illinois. Tight ties might interfere with glaucoma medicine as well, he says. Glaucoma drugs reduce eye pressure by controlling the passage of fluids into and out of the eye, but not pressure due to constricted blood flow. "If you have high-pressure glaucoma, and you're going around with a tight collar or necktie, your pressure will go up and your medicine isn't going to work," Krupin says. Hopefully, the study won't increase the risk of a 1970s-style, open-shirt-and-gold-chain revival.