Basics of Glaucoma

Basics of Glaucoma

The first line of glaucoma treatment is often topical medication. There are a variety of classifications

available today, each treating glaucoma using a different mechanism. These classes of medications are

divided into several groups based on chemical structure and pharmacologic action. The groups of

medications in common clinical use include:

•

Alpha agonists:

decrease production of fluid

and

increase drainage

•

Beta blockers:

decrease production of aqueous fluid

•

Carbonic anhydrase inhibitors (oral and topical):

decrease production of aqueous fluid

•

Cholinergic (miotic) agonists:

constrict the pupil, thereby increasing the drainage of intraocular

fluid through the trabecular meshwork

•

Prostaglandin analogs (hypotensive lipids):

increase uveoscleral drainage

•

Fixed combinations:

combine two or more of the above medications in one bottle

Oral carbonic anhydrase inhibitors such as acetazolamide or methazolamide can be useful for short-term

pressure reduction, or for long-term use when topical drops or surgical options are not sufficient or

tolerated.

Medications, sometimes in combination, have been successful in treating many cases of glaucoma and in

preventing further progression of the disease; however, in most cases, glaucoma cannot be cured.

Because there are few early symptoms, patients may not fully comprehend the need to take their drops

regularly and permanently. The ophthalmic technician and scribe play an important role by emphasizing

the importance of medication compliance. Written instructions as to the medication and frequency of use

are often beneficial in improving compliance. In cases where medical treatment proves inadequate,

physicians may consider surgical options to halt the progression of glaucoma.

SURGICAL MANAGEMENT OF GLAUCOMA

There are two primary types of surgical treatment of glaucoma: laser surgery and incisional surgery. The

section below discusses both types.

Laser Surgery

Laser surgery treats different classes of glaucoma. The laser uses light’s ability to penetrate the

transparent cornea, allowing the surgeon to direct the desired effect on the targeted tissue. In other parts

of the body, the skin or thick outer tissues block penetration. There are different types of lasers, including

krypton, neodymium-YAG, argon, diode, and excimer lasers, for treatment of various eye conditions. A

discussion of some of the common procedures performed with lasers follows:

Argon Laser Trabeculoplasty (ALT): Open-Angle Glaucoma

•

In eyes with open-angle glaucoma, the laser energy is applied directly to the trabecular meshwork

at the junction of the iris and sclera of the anterior chamber angle. The bursts are minute in size.

•

ALT is most successful in eyes that do not have active inflammation.

•

Of the three most common forms of open-angle glaucoma (primary or chronic open-angle

glaucoma, pigmentary glaucoma, and pseudoexfoliative glaucoma), the effect of ALT is often

greatest in the latter.

•

The entire procedure takes less than 10 minutes, is usually painless, and is performed on an

outpatient basis using a topical anesthetic. Dilation of the pupil is not necessary, but constriction

of the pupil with a miotic agent (pilocarpine) is common.