Eye drops and oral medications are the current first choice for treating glaucoma patients in the U.S., sometimes in combination with laser treatments. The goal for all glaucoma treatments is to reduce internal eye pressure by facilitating fluid drainage and/or regulating the amount of fluid produced by the eye. The Glaucoma Research Foundation provides an overview of the most commonly prescribed glaucoma medications and their side effects.*

Types of glaucoma medications

Glaucoma drugs are classified by their active ingredients.

• Prostaglandin analogs (PGAs): Prostaglandins are a group of lipids that the body manufactures at sites of infection or injured tissue. They help control inflammation, blood flow, and blood clot formation. Prostaglandin analogs help increase the outflow of fluid (called aqueous humor, or AH) from the eye, which reduces pressure.
• Beta blockers: High blood pressure increases pressure on the eye, and beta blockers are used to reduce blood pressure. They do this by blocking the fight-or-flight effects of the hormone adrenaline (epinephrine), thus slowing the heartbeat. Beta blockers also dilate blood vessels, which improves blood flow.
• Alpha agonists: Alpha agonists lower intraocular pressure (IOP) by decreasing fluid (AH) production and increasing drainage. 
• Carbonic anhydrase inhibitors (CAIs): Carbonic anhydrase is an enzyme found in a wide variety of body tissues, including the eye. Like alpha agonists, CAIs reduce eye pressure by hindering the production of AH.
• Rho kinase (ROCK) inhibitors: Rho kinase is involved in regulating the shape and size of cells in the body, and it’s linked to factors that affect AH outflow from the eye. ROCK inhibitors change the shape of the fluid’s pathway and, therefore, increase flow.
• Combined medications: For patients who require more than one type of medication, a doctor may prescribe what is called a “combined medications.” Some examples of these are Cosopt®, which is the combination of a beta blocker and a CAI; Combigan®, which is an alpha agonist and a beta blocker; and Simbrinza®, which is a beta blocker-free combination of brinzolamide and brimonidine.

While PGAs are generally the first class of medication prescribed for glaucoma, it’s not uncommon for ophthalmologists to add a second, or even a third, medication to the mix over time, depending on the need. Fluid output fluctuates during the day and night, and since glaucoma drugs work in different ways, sometimes one is not sufficient to regulate eye pressure around-the-clock.

Side effects of glaucoma medications

All medications have potential side effects. Adverse effects of glaucoma medications can range from mild eye irritation to more severe symptoms, such as bleeding, shortness of breath, and depression. 

Some of the most common glaucoma medications and their potential side effects include:

• Prostaglandin analogs: Alteration of eye color, darkening of eyelid, eyelash growth, eyelid droop, sunken appearance of eyes, and eye redness, itching, and stinging.
• Beta blockers: Low blood pressure, slowed pulse rate, fatigue, shortness of breath, decreased libido, and depression, though the latter two occur infrequently.

• Alpha agonists: Drowsiness, dryness of mouth and nose, fatigue, headache, eye burning and/or stinging, and possible allergic reactions. 

• Carbonic anhydrase inhibitors: Eye drops may result in eye stinging or burning. Pills may cause stomach upset, fatigue, frequent urination, memory loss, and tingling sensations in the feet and hands. 
• Rho Kinase Inhibitors: Deposits in your cornea, and redness, stinging, and/or burst small blood vessels in the white parts of the eye. 

Combined medications may result in combined side effects from each of the medications taken. 

Why to take your medications as prescribed

Unpleasant side effects aren’t the only reason why people being treated for glaucoma might not take their drugs as recommended. Some additional reasons include forgetfulness and financial concerns.

Forgetfulness

Getting into the habit of taking a new medication can be a challenge. Taking your glaucoma drugs as directed can make a large difference when it comes to vision preservation, so it’s important to find ways to take your medicine on time from day one. 

A few ways to help you remember are to:

1. Coordinate taking your medicine with another daily activity, such as drinking your morning coffee or brushing your teeth.
2. Set an alarm on your wrist watch or phone.
3. Keep your medicine bottle or package where you can’t help noticing it.

Financial concerns

Like many other medications, glaucoma drugs can be expensive, and some may not be covered by your insurance, depending on your provider and plan. There are, however, organizations and programs that offer financial assistance to help you pay for glaucoma treatments.

*Radhakrishnan, S. and Iwach, A. (2018, July 23). Glaucoma Medications and their Side Effects [Web Page]. Glaucoma Research Foundation. Retrieved July 22, 2020 from https://www.glaucoma.org/gleams/glaucoma-medications-and-their-side-effects.php

Any sources from outside of Prevent Blindness do not imply an endorsement from Prevent Blindness. The contents of the material used are the responsibility of the authoring organization, Responsum Health.