Medical Management / Drops
Most of the patients being treated for glaucoma are started on drops to help lower their IOP (Intraocular Pressure). Here is a list of commonly used classes of medications that are used in the treatment of ocular hypertension and glaucoma.
Different classes of medications often have different colored caps on the bottles and that is how they can be easily recognized by your physician provider.
Prostaglandin analogues (turquoise cap)
Since their introduction to the market in the early 1990’s prostaglandin analogues have become the first line drug of choice for most patients with glaucoma or ocular hypertension, due in part to their effectiveness and ease of use (once nightly dosing). The medication works by increasing the flow of fluid out of the eye (through the uveoscleral system) and therefore reducing the intraocular pressure. It can lower IOP anywhere from 25-35% and is usually administered at night, before bedtime.
Side effects of this medication include mild eye redness, increased pigmentation of the iris (the colored part of the eye), increased eyelash growth, and possible darkening of eyelid skin. Your doctor may avoid prescribing this medication if there is a history of certain eye conditions such as macular edema (swelling in the central part of the retina), herpetic corneal infections, and active inflammation in the eye (iritis/uveitis).
This medication exists in the following formulations:
- Latanoprost (Xalatan, Xelpros – preservative free)
- Travoprost (Travatan)
- Bimatoprost (Lumigan)
- Tafluprost (Zioptan – preservative free)
B-Blockers (yellow cap)
This class of medications works by reducing the amount of fluid (aqueous humor) production inside the eye and thereby lowering the intraocular pressure. It is effective in reducing IOP by about 20-30% for non-selective formulations and 15-20% in B1 selective formulations. The main difference is that the B1-selective blockers are less likely to cause breathing difficulties in patients with existing obstructive lung disease.
Ocular side effects of this medication include burning, redness and corneal anesthesia. Systemic side effects can include low blood pressure, low heart rate, fatigue, shortness of breath, and rarely reduced libido and depression. For these reasons, B-blockers (especially non-selective B-blockers) are typically avoided in patients with a history of asthma/COPD or other breathing problems, bradycardia (slow heart rate) and myasthenia gravis.
Below are the currently available formulations for this class of medications:
- Non-selective
- Timolol Maleate (Timoptic)
- Timolol Hemihydrate (Betimol)
- Timoptic Ocudose (preservative free)
- Cosopt PF (combination of Timolol + Dorzolamide – preservative-free)
- B1 Selective
- Betaxolol (Betoptic-S)
Alpha Agonists (purple cap)
Alpha agonists lower intraocular pressure by primarily lowering the production of fluid (aqueous humor) inside the eye and also partly by increasing the outflow of fluid leaving the eye. This class of medications (specifically Brimonidine) has also been shown to have a possible neuroprotective effect in experimental animal models of glaucoma.
Adverse effects of this medication include burning and an allergic reaction (follicular conjunctivitis) with redness and itching of the eye and eyelids which can occur in 30% of patients. Other systemic effects that have been reported include fatigue, headache, dry mouth and nose, drowsiness, and respiratory depression (especially in neonates).
This class of medications should be used with caution in elderly, those with severely compromised cardiovascular systems, kids younger than 8 years of age, and adults taking MAOIs (monoamine oxidase inhibitors).
Below are the commercially available formulations of this class of drugs:
- Brimonidine (Alphagan P) 0.1%, 0.15%, 0.2%
- Combigan (combination of Brimonidine and B-blocker timolol)
- Simbrinza (Brimonidine + CAI brinzolamide)
CAI’s - Carbonic Anhydrase Inhibitors (orange cap)
This class of medications functions to lower intraocular pressure by reducing the production of aqueous humor inside the eye. These medications are related to the sulfa family of drugs so if you have a severe reaction to sulfa medications please alert your doctor. Many patients with prior allergic reactions to sulfa medications can tolerate CAI’s without significant problems.
This class of medications exists in topical form (eye drops) as well as in pill form (oral medications). Common side effects of topical formulations include burning and stinging on installation, and less frequently a periocular contact dermatitis (eyelid skin becomes red, swollen, crusty and leathery).
Systemic side effects of the oral medications can include tingling of your fingers/toes, metallic taste in mouth, nausea/stomach upset, frequent urination, electrolyte imbalance (loss of potassium) and less frequently drowsiness, depression and kidney stones. For the above reasons the oral formulation of this class of medications is only used as a last resort for a short/limited period of time.
- Eye drops:
- Dorzolamide
- Brinzolamide (Azopt)
- Cosopt (combination of dorzolamide + timolol)
- Simbrinza ( combination of brinzolamide + brimonidine)
- Oral (pill) form:
- Acetazolamide (Diamox)
- Methazolamide (Neptazane) – slightly more expensive, but fewer side effects (better tolerated)
ROCK inhibitors (Rho-Kinase Inhibitors) (white cap)
This class of medications is the latest to be approved by the FDA and just recently came on the market a few years ago. It is a unique class of medications because it is the first one that works directly on the trabecular meshwork (part of the eye where the majority of the fluid flows out through a series of drainage canals) to relax the tissue and allow for improved outflow and therefore lower intraocular pressure. It also has an effect to lower episcleral venous pressure and reduce fluid production slightly, all mechanisms contributing towards a lower intraocular pressure.
It has been clinically proven to be as, if not, more effective than Timolol in published studies. Most common ocular adverse effects include burning, redness and blurred vision. It has no systemic side effects and is easy to use with once nightly dosing.
The following are commercially available formulations of this class of medications:
- Netarsudil (Rhopressa)
- Rocklatan (Netarsudil and Latanoprost combination)