Glaucoma is a group of eye conditions in which the pressure inside of the eye becomes too high. This elevated pressure causes damage to the optic nerve, which can lead to loss of vision. Lowering the eye pressure is the goal of glaucoma treatments. One of the most common types of treatment is glaucoma eye drops. There are several different types of eye drops that lower the eye pressure in different ways; often an eye doctor will prescribe multiple eye drops at once.
Prostaglandin Analogs
Prostaglandin eye drops lower eye pressure by relaxing the muscles in the eye and improving the outflow of the fluid inside the eye. Patients only have to take this type of eye medication once a day, so compliance is usually high. Side effects include potential change in eye color and eyelash growth. Examples include Xalatan (latanoprost), Lumigan (travoprost), Travatan Z (travoprost) and Rescula (unoprostone).
Beta Blockers
Beta blockers lower the pressure in the eye by decreasing the production of the fluid in the eye. These eye medications can impact heart rate and may cause problems in people with lung disease, diabetes or depression. Some available beta blockers are Timoptic XE (timolol maleate), OptiPranolol (metipranolol) and Betoptic S (betaxolol).
Alpha-Adrenergic Agonists
Alpha-adrenergic agonist eye drops also decrease the formation of the fluid inside the eye. Common side effects include red eye, itching and dilation of the pupil. Two of the available glaucoma medications in this class are Iopidine (apraclonidine) and Alphagan (brimonidine tartrate).
Carbonic Anhydrase Inhibitors
Carbonic anhydrase inhibitors decrease the amount of fluid inside the eye as well. This type of glaucoma medication usually is used in combination with other types of eye drops. Common side effects include burning and red eye. While there are a few eye drops in this class of medication such as Trusopt (dorzolamide hydrochloride) and Azopt (brinzolamide hydrochloride), carbonic anhydrase inhibitors also come in pill form.
Combination Medications
Some of the types of eye drops are prescribed together in order to achieve a bigger decrease in eye pressure. However, there are some combination medications where two different eye drops from two different classes of medications are combined to increase effectiveness and improve patient compliance. Examples of these are Cosopt, which is a combination of a beta blocker (Timoptic) and an alpha-adrenergic agonist (Trusopt), and Xalacom, which is a combination of a prostaglandin (Xalatan) and a beta blocker (timolol).
Other Medications
There are other glaucoma eye drops that are not prescribed by eye doctors very often any more. Parasympathomimetics such as pilocarpine increase the outflow of the fluid in the eye; these medications cause the pupil to shrink or constrict. Another type of drop called epinephrine both decreases the production of fluid in the eye and increases the outflow of the eye. These medications are generally used only in special cases or certain types of glaucoma.
