Earlier this year, physicians at the Glaucoma Center of Michigan warned that anticholinergics can lead to acute angle-closure glaucoma, but these are not the only common drugs that can cause this extremely painful condition.

Acute angle-closure crisis can lead to vision loss if not treated immediately. It occurs when the pupils dilate and trap aqueous humor between the iris and cornea. Pressure from the aqueous humor, which is unable to flow normally, increases and pushes the iris against the trabecular meshwork. During an acute angle-closure crisis, pressure within the eye can approach five times the normal level. Such high pressure can damage the optic nerve in just a couple of days.

Connections between the brain and the gastrointestinal tract can lead to abdominal pain, nausea, and vomiting, sometimes so severe that physicians may initially suspect appendicitis.

Other common symptoms include blurred vision or other visual disruption, eye redness, and enlarged or irregular pupil shape. Medications that increase the risk of acute angle-closure glaucoma include anticholinergics commonly found in OTC cold, nausea, and allergy medications such as brompheniramine, chlorpheniramine, dimenhydrinate, diphenhydramine, doxylamine, meclizine, promethazine, pyrilamine, and triprolidine.

Prescription anticholinergics that increase the risk include those used to treat asthma and chronic obstructive pulmonary disease (ipratropium bromide and tiotropium bromide), overactive bladder (tolterodine and oxybutynin),and antacids (cimetidine and ranitidine). Both selective serotonin reuptake inhibitors and tricyclic antidepressants have anticholinergic effects.

Other drugs that may cause acute angle-closure crisis include ephedrine, sulfonamide, and oral steroids.

Topiramate, which is commonly prescribed for migraines, also increases the risk of this unusual form of glaucoma.

Because individuals who take topiramate typically already experience frequent, severe headaches, asking about the location of the pain and other symptoms may help distinguish an acute angle-closure crisis from a particularly ferocious migraine and direct them to care that could save their sight.

While anyone can experience acute angle-closure glaucoma, the condition occurs most often in people over age 50 years with cataracts, those with farsightedness, women, Asians, and individuals known to have narrow angles or who have a family history of angle-closure glaucoma.

Customers with acute angle-closure glaucoma are experiencing a medical emergency and should be seen immediately by an ophthalmologist or an emergency department with an ophthalmologist on call. Without treatment, blindness can occur in 1 or 2 days.

Treatment focuses on reducing pressure in the eye, either through eye drops or creating a hole in the iris, usually with a laser. Laser iridotomy can relieve pressure and resolve pain immediately. All implicated medications should be stopped as well.

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