7 Types of Glaucoma Eye Drops

Following a glaucoma diagnosis—which can be a lengthy process—you may have conflicting emotions. 

On the one hand, having a firm diagnosis can be comforting since you finally know what you have and how to proceed with treatment. On the other hand, you're probably curious about exactly how you'll treat your glaucoma.

Usually, one of the first treatments that healthcare providers recommend in treating glaucoma is eye drops. Here's what you should know about the seven types of commonly prescribed eye drops and their possible side effects.

How Do Eye Drops Treat Glaucoma?

Most commonly, healthcare providers prescribe eye drops to treat glaucoma, Christopher Starr, MD, an ophthalmologist at Weill Cornell Medicine, told Health. Eye drops treat glaucoma and prevent optic nerve damage by reducing intraocular pressure (IOP). An imbalance of fluids in the eye causes IOP. 

"[IOP] is the number-one modifiable risk factor of glaucoma, so we treat the pressure," said Dr. Starr. There are many different classes and specific types of eye drops that can help reduce IOP. "Some drops reduce production of aqueous humor [a type of fluid]. Others increase the outflow from the eye." 

List of Eye Drops for Glaucoma

Not everyone responds to every type of eye drop, Courtney Ondeck, MD, MPhil, an instructor in ophthalmology at Harvard Medical School, told Health. Additionally, people with advanced glaucoma may need to use a few different kinds of eye drops to tackle IOP from multiple angles.

A healthcare provider will likely start you on one type, then wait a few weeks to see if it's lowering IOP. If not, a healthcare provider may try a different eye drop in that category, one from another class, or a combination of two different types of drops. Eventually, if eye drops don't lower IOP, a healthcare provider may suggest lasers and surgery.

All eye drops may cause red, stinging, itching, painful eyes, dryness, and blurry vision after using them. Overall, seven different types of eye drops can treat glaucoma.

Prostaglandin Analogs

Prostaglandin analogs work by increasing the outflow of fluid from the eye. Some commonly prescribed prostaglandin analogs include:

• Xalatan (latanoprost)
• Travatan Z (travoprost)
• Zioptan (tafluprost)
• Lumigan (bimatoprost)

"Patients usually tolerate these pretty well. There are only a few minor side effects," said Dr. Ondeck. Some of the most common side effects of prostaglandin analogs include the following:

• Eye color change
• Darkening of the eyelid skin
• Eyelash growth
• Droopy eyelids
• Sunken eyes
• Light sensitivity

People with glaucoma only need to use prostaglandin analogs once daily. So, there's a good chance that people will use them as prescribed, ultimately increasing their efficacy. 

"Compliance is a major issue," noted Dr. Ondeck. "It's so much easier to remember to take medication once a day than three times a day."

Beta-Blockers

Beta-blockers lower IOP by decreasing the production of fluid in the eye. Some commonly prescribed beta blockers include:

• Betoptic (betaxolol)
• Timoptic or Betimol (timolol)
• Istalol or Timoptic in Ocudose (timolol maleate)

The downside to drops in that class is that they can have systemic side effects. In other words, side effects extend beyond just the eye and may include:

• Low blood pressure
• Fatigue
• Reduced pulse rate
• Irregular heartbeat
• Dizziness
• Shortness of breath

Those side effects are similar to how other beta-blockers (usually given to people with high blood pressure) work. Beta-blockers aren't good for people with asthma or respiratory conditions, like chronic obstructive pulmonary disease (COPD), because they may cause shortness of breath. Rarely, beta blockers can also cause low libido and depression.

People with glaucoma only need to take some beta blockers once daily. So, beta blocks can be a good option if you do not have pre-existing conditions that may worsen due to the potential side effects.

Carbonic Anhydrase Inhibitors (CAIs)

CAIs, available as eye drops or oral pills, decrease aqueous production in the eye. Some commonly prescribed CAIs include:

• Neptazane (methazolamide)
• Diamox Sequels (acetazolamide)
• Trusopt (dorzolamide)
• Azopt (brinzolamide)  

Some of the most common side effects of CAIs include:

• Rash
• Change in taste
• Abdominal pain
• Nausea
• Vomiting
• Fatigue
• Mental fuzziness
• Memory problems
• Depression

Additionally, side effects from the oral pill versions of CAIs specifically include:

• Tingling and weakness in the hands and feet
• Frequent urination
• Kidney stones

"[CAIs] need to be used with caution in people who have kidney issues," said Dr. Ondeck. People with glaucoma usually take CAIs three times daily to lower IOP. So, compliance can be an issue for some people, added Dr. Ondeck.

Alpha Agonists

Alpha agonists work by decreasing the production of fluid in the eyes and increasing drainage. Alpha agonists have two types of eyedrops: brimonidine and apraclonidine. Some commonly prescribed alpha agonists include Alphagan P or Qoliana (brimonidine tartrate) and Iopidine (apraclonidine).

Some of the potential side effects of alpha agonists include:

• Headaches
• Dilated eyes
• Drowsiness
• Dry mouth and nose
• Increase in blood pressure
• Irregular heartbeat

Also, according to Dr. Ondeck, alpha agonists can cause conjunctivitis (pink eye) and significant fatigue in older adults. 

In particular, healthcare providers do not recommend brimonidine for children and infants. Brimonidine passes through the blood-brain barrier, which may cause central nervous system (CNS) depression and toxicity. Complications include low blood pressure, slow heart rate, and hypothermia.

People with glaucoma usually use alpha antagonists three times daily for maximum efficacy.

Cholinergics (Miotic)

Cholinergic eye drops make the pupil smaller, which increases fluid drainage from the eye. Examples of cholinergic eye drops include Isopto Carbachol or Miostat (carbachol).

Cholinergic eye drops can also cause systemic side effects, such as:

• Dim vision (especially at night or in dark areas)
• Nearsightedness
• Headache

However, healthcare providers do not commonly prescribe cholinergic eye drops because of their potential side effects.

Rho Kinase Inhibitors

Rho kinase inhibitors, like Rhopressa (netarsudil), improve the outflow of ocular fluid.

Generally, rho kinase inhibitors don't cause systemic side effects. Still, some side effects of rho kinase inhibitors include:

• Corneal deposits
• Stinging
• Small bleeding underneath the skin of the eye and on the whites of the eyes 

Typically, people with glaucoma use rho kinase inhibitors once daily.

Combination Treatments

Combination medications are two different classes of eye drops combined into one medication. You may need to use two different types of drops to control your eye pressure effectively. A combination of eye drops also helps with compliance, said Dr. Ondeck. 

Some commonly prescribed combination medications include:

• Rocklatan (rho kinase inhibitor and prostaglandin analog)
• Combigan (beta blocker and alpha agonist)
• Cosopt (beta blocker and carbonic anhydrase inhibitor)
• Simbrinza (carbonic anhydrase inhibitor and alpha agonist)

"The only issue is sometimes they are only brand name drops. So, it could be an issue with getting insurance approval," added Dr. Ondeck. 

The number of times people with glaucoma use combination medications daily depends on the formula.

A Quick Review

Reducing IOP is one of the first steps in treating glaucoma. Several medications reduce that pressure, and eye drops are some of the easiest ways to deliver those medications. 

There are seven types of eye drops to treat glaucoma. Most eye drops cause dry, red, stinging, itching, or painful eyes and blurry vision after using them. But some have systemic side effects, affecting other body parts. Talking to a healthcare provider is important to determine what eye drop is right for you.