What types of treatment methods are available for glaucoma?
The only proven method of treatment for glaucoma
is reducing the pressure inside the eye. There are three ways to lower the eye
pressure for glaucoma: medications (usually taken as eye drops), laser
treatment, and surgical treatment. For most patients with newly diagnosed or
easily controlled glaucoma, one or more types of eye drops are used daily. Some
patients’ eye pressures cannot be adequately controlled with eye drops (or the
patients have allergies to or side effects from medication) and laser treatment
or surgery is needed. Sometimes, laser treatment can be performed first to treat
open-angle glaucoma, but medication is frequently needed later. If medication
and laser both fail to control intraocular pressure, surgery (usually a
trabeculectomy) becomes necessary. For severe cases of glaucoma, less common
procedures (such as a glaucoma implant) are performed.
Laser treatment is required early in most cases of
angle-closure glaucoma and is used as an alternative or supplement to treatment
in open-angle glaucoma.
The goal in treating glaucoma is to preserve the patient's vision by reducing intraocular (inside the eye) pressure and protecting the optic nerve.
Medical therapy
There are several classes of medications
used to treat glaucoma, with many advances having been made over the past
several years. Each medication has a different mechanism of reducing pressure,
either working to reduce the production of aqueous humor (fluid in the front
part of the eye), or to reduce the resistance to the outflow of aqueous. These
medications can be used individually or together to complement each other. Side
effects can occur are uncommon. Your doctor will explain which medication is
right for you. Please let your doctor know if you believe you are experiencing
side effects from your glaucoma medication.
The following medications can be used to treat glaucoma:
- Beta-blockers:
Beta-blockers (betaxolol, carteolol, levobunolol, metipranolol, timolol)
work by reducing aqueous production. They have a long, proven track record
of effectiveness and are used once or twice daily. They are inexpensive and
safe for most patients, but beta-blockers should NOT be used by patients
with asthma, chronic lung disease, heart-block, hypotension, or severe heart failure.
- Alpha-2 agonists: These medications (apraclonidine, brimonidine) also work by reducing aqueous production. They are slightly less effective than beta-blockers and are used
twice daily. Their side effects can include an allergic reaction, redness or
irritation in the eyes, occasional headaches, and, in rare instances, a
decrease in mental alertness.
- Carbonic anhydrase inhibitors:
These medications work by reducing aqueous production. The side effects of
oral carbonic anhydrase inhibitors (acetazolamide, methazolamide) include
fatigue, loss of appetite, numbness and/or tingling in the hands and feet,
and stomach upset. When used as a topical medication (brinzolamide,
dorzolamide), carbonic anhydrase inhibitors are a little less effective, but
there are very few side effects except occasional allergic reactions.
- Prostaglandins:
Prostaglandins (bimatoprost, latanoprost, travoprost, unoprostone) work by
decreasing the resistance to aqueous outflow and have been shown to be very
effective in reducing intraocular pressure. Side effects include redness,
irritation or inflammation in the eye, darkening of the iris color and an
increased growth of eyelashes.
- Miotics: Miotics such as
carbachol, echothiophate, and pilocarpine are effective and inexpensive.
However, their side effects of brow ache and dim or blurred vision have
reduced their use.
- Combination medication: Cosopt (timolol and dorzolamide) is used twice daily. The medication has two glaucoma medications in one bottle, thus reducing the number of different
glaucoma medication bottles needed.
Laser surgery
If medications do not sufficiently reduce the intraocular pressure, laser
surgery is an alternative. Most glaucoma laser treatments take only one or two
minutes and are performed directly in the clinic with topical (eye drop)
anesthesia. There are a number of laser surgeries used to treat glaucoma. These
include:
Laser trabeculoplasty: Laser trabeculoplasty is the
most commonly performed glaucoma procedure in the United States, and can
be considered as an alternative to one glaucoma medication as therapy
for newly diagnosed or established glaucoma. During this procedure, the
trabecular mesh-work (drainage canals surrounding the iris) is mildly
treated with 60-100 tiny laser spots, causing the trabecular mesh-work to
open more. This allows for an increase in the aqueous outflow in the
area surrounding the laser spot, thus relieving pressure inside the eye.
Pressure is reduced in 60-70 percent of the patients in whom a laser
trabeculoplasty is performed, however, about half of those patients
require further medical or surgical treatment within two to five years.
Laser trabeculoplasty is a quick, easy, convenient, and relatively
low-risk procedure, but has a relatively small effect on lowering the
eye pressure and repeat treatments are usually not very effective. In
some people, such as individuals with glaucoma from eye inflammation or
eye trauma, the procedure has no benefit and can worsen the glaucoma.
Glaucoma medications are usually continued after laser trabeculoplasty.
- Selective laser trabeculoplasty: This procedure is similar
to a standard laser trabeculoplasty. It involves using a laser with a
different wavelength than the argon or diode laser more commonly used.
- Laser peripheral iridotomy: This procedure, which is required in most cases of angle-closure glaucoma, creates a tiny permanent opening in the iris. This small opening reduces the fluid pressure behind the iris, and allows it to fall backward, away from the drainage
channels of the eye. If complete opening of the channels occurs, the
intraocular pressure may return to normal without the need for any
additional glaucoma medication.
- Laser peripheral iridoplasty: This is a rather uncommon
procedure, used to further open an angle, which may still be narrow
after a successful laser peripheral iridotomy.
- Laser cyclophotocoagulation: Another less-commonly
performed laser usually reserved for glaucoma in low-vision eyes. This
laser can cause some pain. Other lasers for glaucoma usually cause
little or no discomfort.
Incisional glaucoma surgery
Glaucoma surgery is performed as an outpatient procedure, usually with local
anesthesia, and with or without intravenous sedation. The surgery is performed
under an operating microscope and tiny instruments are used. After glaucoma
surgery, patients can wear their eyeglasses and usually wear a protective shield
only at bedtime for one to two weeks. The most commonly performed glaucoma
incisional surgery, trabeculectomy, creates an alternative channel to divert
aqueous from the eye, usually to the subconjunctival space. Glaucoma surgical
procedures can usually be performed in about 25-35 minutes. Glaucoma surgery
often reduces or eliminates the need for future glaucoma medications in the operated eye.
For some patients with a higher risk to scar a trabeculectomy, the surgeon
may use an anti fibrosing medication such as 5-fluorouracil or mitomycin C.
What is a glaucoma implant (glaucoma drainage device)?
There are several of types of glaucoma implants for glaucoma surgery.
Glaucoma implant surgery is a somewhat longer and more technically involved
procedure than a trabeculectomy. Three of the more commonly used glaucoma
implants are the Ahmed, Baerveldt, and Molteno implants. Glaucoma implants have
two components:
- A small tube that is placed in the front or back of the eye to collect fluid
- The plate connected to the tube that forms a natural chamber of tissue
to collect and release the fluid from your eye
Glaucoma implants are generally reserved for cases of severe glaucoma due to
more unusual conditions, such as abnormal vessels in the front of the eye of
some people with diabetes, and glaucoma caused by ocular inflammation. Implant
surgery is also used in some individuals who have previously had a
trabeculectomy that was not successful.
Combined cataract and glaucoma surgery
Patients with a visually significant cataract can have elective cataract
surgery. Cataracts are not treatable with medication or laser. Patients with
cataract and mild or easily controlled glaucoma can usually have straightforward
cataract surgery. However, patients with cataract and more significant or
difficult to control glaucoma may benefit from combined cataract and glaucoma
surgery. When successful, combined surgery can improve visual acuity, reduce
eyeglass dependency and reduce the need for glaucoma medication.
Are there risks of glaucoma surgery?
Any type of eye surgery has some risk. Risks to your general health are
reduced by using local rather than general anesthesia for most patients. The
glaucoma operation may fail and require glaucoma medication or another glaucoma
operation. Frequently, the eye pressure becomes very low immediately after
surgery. This is harmless over a short period of time; however, over a long
period of time, this may cause vision changes. Occasionally, there is a leak
from the surgery, which often closes naturally. Any eye surgery has the risk of
bleeding in the eye or infection, but the risk is usually less than one percent
(1%) and precautions are taken to reduce that risk.
However, these risks must be compared to the risks of uncontrolled glaucoma,
which can lead to a total and permanent loss of vision, if the pressure can not
be controlled with eye drops, laser or surgery.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 3/5/2009…#10794
