Acute closed-angle glaucoma is an emergency situation. When fluid is suddenly blocked from draining out of the eye, pressure increases quickly, causing damage to the optic nerve. If acute closed-angle glaucoma is not treated, blindness develops rapidly.

• Several medications may be needed to lower the intraocular pressure (IOP). Eyedrops that block the production of fluid (aqueous humor) are usually used first. If eyedrops do not lower the pressure, oral or intravenous (IV) medications may be used.
• The drainage angle may be checked often using gonioscopy to monitor the effects of the medications on the angle. See gonioscopy in the Exams and Tests section of this topic.
• If medication does not lower the pressure, the person may need emergency laser treatment or surgery. Laser treatment or surgery creates a way for fluid to move easily from the back part (posterior chamber) to the front part (anterior chamber) of the eye.
• When medication is able to lower the pressure, laser treatment (laser iridotomy) is commonly done 1 week later. Surgery (surgical iridectomy) is used for difficult cases. See the Surgery section of this topic.
• Although closed-angle glaucoma affects one eye first, the other eye often (about half of the time) develops the condition within 5 years.¹ For this reason, the other eye is examined and also treated with a laser to prevent the condition from developing in it.