Treatment of glaucoma begins

April 1, 2010
Elaine Zablocki
Elaine Zablocki

Two of the major causes of blindness in the United States are glaucoma and age-related macular degeneration (AMD), which often can be controlled with medication.

Two of the major causes of blindness in the United States are glaucoma and age-related macular degeneration (AMD). However, medications are available for both conditions that substantially limit their effects, especially when treatment is started early.

In glaucoma, the fluid inside the eye doesn't drain normally, so excess pressure builds up within the eye. As this goes on, the structure of the eye is damaged, resulting in blurred vision, a narrowed field of sight and eventual blindness. While anyone can develop glaucoma, those at highest risk include African Americans over age 40, those with a family history of glaucoma, and anyone over age 60.

It is important for patients to receive regular checkups, including a dilated eye exam.

EARLY DIAGNOSIS IS CRITICAL

The early stages of glaucoma typically affect peripheral vision, and patients don't experience any symptoms. Even though they have increased eye pressure, they don't feel it.

"By the time people come in because they are actually noticing vision problems, at that point they have sustained major damage to the optic nerve," Dr. Iwach says.

Once the early stages of glaucoma are identified during a routine eye exam, ophthalmologists do have effective medications to reduce pressure within the eye. Beta-blockers used to be the first line treatment for glaucoma, and they are still used under certain circumstances.

"The problem with beta-blockers is they are systemic medications, which tend to exacerbate asthma and chronic obstructive pulmonary disease, limit the maximal heart rate, and lead to depression," says Mark Packer, MD, an ophthalmologist in private practice in Eugene, Ore., and an associate clinical professor at Oregon Health Sciences University.

Starting in the mid-1990s, prostaglandin analogs, which do not affect systemic bodily functions, became the first line choice for treatment of glaucoma.

"They offer once-a-day dosing, which is by far the most convenient and also has the highest compliance rate," Dr. Packer says. "In addition, the absence of systemic side effects is of great importance."

Treatment for glaucoma starts out with one of the prostaglandin analogs, and if needed a second medication may be added.

"Treatment of glaucoma is all about the target pressure," says Dr. Packer. "Let's say that some damage has occurred at the current pressure, so as a starting point, we think the pressure should be 20% lower. Generally speaking, we first try a prostaglandin and then try other medications to see their effect. The period for maximal efficacy is usually about two to four weeks, and then we check the pressure in the eye again."

"This disease is potentially blinding, and yet it has no symptoms in its early stages," says Dr. Packer. "The treatment regimen is complex. Sometimes the patient has to do the first drop, than wait five minutes to do the second drop. Patients with arthritis may have problems squeezing the bottle."

Drug compliance programs should be considered for glaucoma patients.