Medications
Medications to lower the pressure inside
the eye (intraocular pressure, or IOP) are used
to treat all types of
glaucoma. They work either by reducing the amount of
fluid (aqueous humor) that is produced by the eye or by
increasing the amount of fluid that drains out of the eye. These medicines may
be given as eyedrops; as pills; in liquid form by mouth; or, in emergency
situations, through a vein. In most cases, eyedrops are used first.
In a sudden (acute) attack of
closed-angle glaucoma, medicines may be used to lower
the pressure in the eye. Medicines that close (constrict) the pupil may be used
to open the
drainage angle. If medicines lower the eye pressure
after an episode of acute closed-angle glaucoma, laser treatment is usually
done soon afterwards to prevent such an episode from occurring again. If the
medicines do not lower the pressure in the eye, laser treatment will need to be
done immediately.
In
congenital glaucoma, medicines may be used to reduce
the pressure in the eyes and decrease the cloudiness of the clear front surface
(cornea) of the eye. Medicines usually do not work over a long period of time
and are usually used only until surgery can be done.
In the media,
much has been said about the possibility of using
marijuana to treat glaucoma. Inhaled marijuana smoke
has been shown to result in an average 25% reduction in intraocular pressure
(IOP), but the effect lasts only for about 3 to 4 hours. Also, not all people
who use marijuana have this reduction in IOP; it only occurs in about 60% to
65% of users. The smoke also has toxic effects on other parts of the body,
particularly the lungs, and substances in the smoke cause changes in mental
state. The amount of marijuana a person needs to smoke to keep eye pressure
down would cause significant side effects. Because of these toxic and
psychoactive effects, along with the short duration of the beneficial effect of
lowering pressure in the eye, marijuana is considered a poor treatment option
and is not recommended for glaucoma.11
Medication Choices
Medicines used to treat glaucoma lower the pressure in
the eyes (intraocular pressure, or IOP) by either decreasing the amount of
fluid produced by the eyes or increasing the amount of fluid that drains out of
the eyes.
Medicines that decrease the amount of fluid produced by
the eye include:
- Beta-blockers (such as Betagan,
Betimol, Betoptic, Ocupress, OptiPranolol, and Timoptic).
- Adrenergic agonists (such as Alphagan, Epifrin,
Iopidine, and Propine).
- Carbonic anhydrase inhibitors (such as Azopt, Diamox,
Neptazane, and Trusopt).
- Hyperosmotics (such as Osmitrol,
Osmoglyn, and Ureaphil).
Medicines that increase the amount of fluid that drains
out of the eye include:
- Cholinergics (such as Carboptic, Isopto
Carpine, Phospholine Iodide, Pilocar, Pilopine HS, and
Pilostat).
- Adrenergic agonists (such as Alphagan,
Epifrin, Iopidine, and Propine).
- Prostaglandin
analogs (such as Lumigan, Travatan, and Xalatan).
Some medicines have two different medicines mixed into
one bottle. Examples include Cosopt, which contains both a carbonic anhydrase
inhibitor and a beta-blocker, and Combigan, which contains both an adrenergic
agonist and a beta-blocker.
What To Think About
When medicines are used to treat
glaucoma, the goal is to prevent further damage to the optic nerve by lowering
the pressure in the eyes. The level of pressure in the eye needed to damage the
optic nerve varies from one person to another. For this reason, a single
target eye pressure cannot be used for everyone. Your
target pressure may need to be adjusted if the optic nerve shows further damage
despite treatment.
When glaucoma has already caused vision loss,
further vision loss may develop even after the pressure in the eye is lowered
to the normal range with medicine.
In most cases, medicines used
to treat glaucoma must be continued daily for the rest of your life. Putting
eyedrops in the eye at specific times of the day may be inconvenient. Eyedrops
may also cause discomfort. You need to follow the prescribed daily schedule for
your eyedrops in order for them to work properly.
- Discuss the goals of treatment, how long the
medicine will be tried, and the possible side effects with your health
professional. Eye medicines can cause symptoms throughout the body. Report side
effects to your eye doctor.
- Knowing how to correctly insert your
eyedrops can make the medicine work better and may help you avoid side effects.
A medicine card stating which medicines need to be taken at different times of
the day can be helpful in reminding you to take medicines. Use multicolored
bottle caps to help you tell different medicines apart.
- You will
need follow-up visits with your health professional shortly after starting a
new medication to determine whether it is working as well as it should be and
to discuss any side effects or medication schedule problems.
Medicines for glaucoma can be expensive. Some
cost-saving tips such as using a measured-dose
dispenser may help.
Let all your health professionals know that
you are taking glaucoma medicines. Other medicines that you are taking may need
to be adjusted or stopped to prevent side effects.
While there are
fewer complications from the new surgical procedures for glaucoma, medication
treatment still usually has fewer side effects than surgery. Many people who
use glaucoma medicines may never need surgery for glaucoma.