While there is no cure for glaucoma, it can be controlled with proper management.
Elevated
intraocular pressure (IOP) can damage the optic nerve, which may lead
to vision loss. Treatment for glaucoma focuses on lowering the IOP to a
level that is less likely to cause further optic nerve damage. This is
known as the “target pressure.” The target pressure differs from
individual to individual. Your target pressure may change during your
course of treatment if the progression of glaucoma is not arrested.
If you have
glaucoma, your ophthalmologist (Eye M.D.) may prescribe medication to
lower your eye IOP. There are many more choices for topical treatment
today than there were only a few years ago. Your ophthalmologist has
chosen a beta-blocker medication to treat your glaucoma.
How Do Beta Blockers Work?
Beta-blocker (beta adrenergic antagonist) medications are
reliable for lowering intraocular pressure. They work by decreasing the
amount of fluid that the eye continually produces, called the aqueous
humor. For many years, beta blockers were the mainstay of treatment.
Thus, we have a lot of experience with this medication for the
treatment of glaucoma.
Types of Beta-Blocker Medications
There are two general classes of beta blockers: nonselective
and selective. Nonselective beta blockers have more effects on the
body’s beta receptors system-wide and are associated with more side
effects. The nonselective beta blockers are also more effective at
lowering IOP.
The nonselective beta blockers include
- levobunolol (Betagan, AKBeta);
- carteolol (Ocupress);
- metipranolol (Optipranolol);
- timolol (Timoptic, Betimal, Istalol); and
- timolol gel (Timoptic XE).
Generic
versions of timolol and timolol gel are now available. Consult with
your ophthalmologist to be sure that a generic product is an acceptable
alternative for you.
The only available selective beta-blocker medication is
- betaxolol (Betoptic, Betoptic S).
Betaxolol is the generic form of Betoptic.
While a
selective beta-blocker eyedrop has a better safety profile, especially
in terms of respiratory symptoms, it still must be used with caution in
patients with asthma or emphysema. The eye pressure-lowering effect is
slightly less with selective beta blockers. There is only a minimal
additive effect in terms of lowering eye pressure in patients already
taking oral beta blockers, and there is the risk of further additive
side effects. If you are already taking a beta-blocker medication by
mouth or if your primary care doctor newly prescribes a beta blocker,
please notify your ophthalmologist.
Possible Side Effects of Beta Blockers
All medications, including eyedrops, can have side effects. Some people taking beta-blocker eyedrops may experience
- wheezing or difficulty breathing;
- slow or irregular heart beat or decreased response of heart rate to exercise;
- increased risk for heart failure;
- depression;
- impotence;
- headache, dizziness or weakness;
- in diabetics, difficulty sensing blood glucose changes; and
- eye irritation or allergy.
Medication Tips
For glaucoma medications to work, you must take them regularly
and as prescribed by your doctor. With each new medication that your
ophthalmologist prescribes, make sure you understand the following:
- the name of the medication;
- how to take it;
- how often to take it;
- how to store it;
- if you can
take it with your other medications (make sure all of your doctors know
about all the different medications you take, including any
nonprescription medications);
- what the possible side effects may be;
- what you should do if you experience side effects; and
- what you should do if you miss a dose.
(c) 2007 The American Academy of Ophthalmology