Do you know of any reason why someone using pressure-controlling eyedrops should not take ginkgo herbal supplements? I've been taking ginkgo for six months, and during that time, my eye pressure has increased to 19, up from 14. I have used Xalatan drops nightly for two years to control my eye pressure, and we are about to add another beta-blocker prescription eyedrop to the treatment.

W.D.

Many older people take ginkgo biloba because some studies have suggested that it may improve one's memory. Because this herbal preparation "thins" the blood, concerns have been raised about the effect it may have when combined with other medications or supplements that slow blood clotting, such as aspirin and vitamin E. However, it is not known whether ginkgo or other ingredients found in ginkgo supplements may interact with glaucoma medications, such as Xalatan.

Glaucoma is a condition in which the pressure within the eye is elevated. If the pressure is not brought under control with Xalatan or other medications, glaucoma can damage the optic nerve and lead to blindness.

If you suspect ginkgo may be interfering with your glaucoma medication, you may want to stop taking the herbal supplement and have your eye doctor check to see if it makes any difference in your eye pressure.

Also, keep in mind that the recent rise in your eye pressure may have occurred whether or not you were taking the ginkgo. While Xalatan is effective at lowering eye pressure in many patients with mild to moderate glaucoma, it is common for patients with moderate to severe glaucoma to need additional medications. Please talk with your doctor to determine what the best course of action is to control your eye pressure.