Glaucoma is an eye disease caused by damage to the optic nerve. This damage is usually caused by pressure on the nerve due to buildup of fluids called aqueous humor inside the eye. Medication for glaucoma usually comes in the form of eye drops that either decrease the production of aqueous humor or increase the rate at which the fluids drain from the eye. If eye drops are not effective, oral medications or surgery may be necessary to prevent vision loss.
There are two common types of glaucoma: primary open angle glaucoma and angle closure glaucoma. Primary open angle glaucoma happens when the drainage channels in the eye become blocked. It is typically a gradual process, with vision becoming worse over time. Angle closure glaucoma typically happens much more suddenly, and when it does, it is considered a medical emergency. Angle closure glaucoma is caused by the iris bulging forward into the drainage angle between the cornea and iris, blocking drainage of fluid from the eye.
Angle closure glaucoma is usually treated in the hospital. Medication for glaucoma during a hospital stay is usually administered through an IV or injection. Usually doctors will use several types of medication to decrease the eye pressure as quickly as possible.
Medicated eye drops are the most common medication for glaucoma. Prostaglandin-like compounds, miotic or cholinergic agents, and epinephrine compounds are all types of medicated eye drops that increase the drainage of aqueous humor. Alpha agonists increase drainage and also decrease the production of aqueous humor inside the eye. Beta blockers and carbonic anhydrase inhibitors reduce the production and amount of aqueous humor.
If medicated eye drops are not enough to decrease the pressure inside the eye, another medication for glaucoma may be prescribed. Carbonic anhydrase inhibitors can also be taken orally for greater effectiveness. Different people may experience different side effects, so often a physician will try a few different medications before finding the best one for a specific patient.
If medication for glaucoma is not effective, surgery is another option. The most common type of surgery is a type of laser surgery where a high energy laser beam is used to open the drainage pathways that have become blocked. This is a short and simple procedure that does not require a hospital stay. To treat acute glaucoma or glaucoma that has not responded to medications or laser surgery, a trabeculectomy may be necessary. In this procedure, a surgeon creates an opening in the eye for fluid to drain freely.