Eye Health Center

Medicines to lower the pressure inside the eye (intraocular pressure, or IOP) are used to treat all types of glaucoma. They work either by reducing the amount of fluid (aqueous humor) that is produced by the eye or by increasing the amount of fluid that drains out of the eye. These medicines may be given as eyedrops; as pills; in liquid form by mouth; or, in emergency situations, through a vein. In most cases, eyedrops are used first.

In a sudden (acute) attack of closed-angle glaucoma, medicines may be used to lower the pressure in the eye. Medicines that close (constrict) the pupil may be used to open the drainage angle. If medicines lower the eye pressure after an episode of acute closed-angle glaucoma, laser treatment is usually done soon afterwards to prevent such an episode from occurring again. If the medicines do not lower the pressure in the eye, laser treatment will need to be done immediately.

In congenital glaucoma, medicines may be used to reduce the pressure in the eyes and decrease the cloudiness of the clear front surface (cornea) of the eye. Medicines usually do not work over a long period of time and are usually used only until surgery can be done.

In the media, much has been said about the possibility of using marijuana to treat glaucoma. Inhaled marijuana smoke has been shown to result in an average 25% reduction in intraocular pressure (IOP), but the effect lasts only for about 3 to 4 hours. Also, not all people who use marijuana have this reduction in IOP; it only occurs in about 60% to 65% of users. The smoke also has toxic effects on other parts of the body, particularly the lungs, and substances in the smoke cause changes in mental state. The amount of marijuana a person needs to smoke to keep eye pressure down would cause significant side effects. Because of these toxic and psychoactive effects, along with the short duration of the beneficial effect of lowering pressure in the eye, marijuana is considered a poor treatment option and is not recommended for glaucoma.¹¹

Medication Choices

Medicines used to treat glaucoma lower the pressure in the eyes (intraocular pressure, or IOP) by either decreasing the amount of fluid produced by the eyes or increasing the amount of fluid that drains out of the eyes.

Medicines that decrease the amount of fluid produced by the eye include:

• Beta-blockers (such as Betagan, Betimol, Betoptic, Ocupress, OptiPranolol, and Timoptic).
• Adrenergic agonists (such as Alphagan, Epifrin, Iopidine, and Propine).
• Carbonic anhydrase inhibitors (such as Azopt, Diamox, Neptazane, and Trusopt).
• Hyperosmotics (such as Osmitrol, Osmoglyn, and Ureaphil).

Medicines that increase the amount of fluid that drains out of the eye include:

• Cholinergics (such as Carboptic, Isopto Carpine, Phospholine, Pilocar, Pilopine, and Pilostat).
• Adrenergic agonists (such as Alphagan, Epifrin, Iopidine, and Propine).
• Prostaglandin analogs (such as Lumigan, Travatan, and Xalatan).