Laser therapy is a safe and effective alternative to eyedrops as a first-line treatment for patients with newly diagnosed primary open-angle glaucoma, according to research results released today.
The finding comes from a follow-up study of patients in the nationwide Glaucoma Laser Trial (GLT), sponsored by the National EyeInstitute of the National Institutes of Health. The study was done to learn if early laser treatment is safe and whether it offers any medical advantages over eyedrops for newly diagnosed open-angle glaucoma.
After some 7 years of followup, all measures used to evaluate the two treatments showed that the “laser first” eyes and the “medication first” eyes had a similar status on all measures used to evaluate the two treatments. Researchers assessed changes in the patient's visual field, visual acuity (sharpness), intraocular pressure, and optic nerve.
“Our results suggest that initial treatment with laser is at least as effective as an initial treatment with eyedrops,” said HughBeckman, M.D. of Sinai Hospital in Detroit, the study’s chairman.
However, researchers cautioned that neither treatment method is a “magic bullet” for long-term control of glaucoma. They noted that two years after the start of treatment, 56 percent of “laser first” eyes and 70 percent of “medication first” eyes needed new or extra medications to control the pressure inside the eye.
Carl Kupfer, M.D., director of the National Eye Institute, stated that whichever first treatment is chosen for newly diagnosed glaucoma,”the disease is a long-term, chronic illness that must be controlled over the patient’s lifetime in order to save vision.”
About 3 million Americans have open-angle glaucoma, the most common form of glaucoma in the U.S. For unknown reasons, small changes within the eye gradually interfere with the normal flow of fluids that feed tissues in the front of the eye. If these fluids do not drain properly, the resulting higher pressure inside the eye can damage the optic nerve and narrow the field of vision. This change happens so slowly that many people are not diagnosed with glaucoma until they have a significant loss of vision.
A total of 271 patients were enrolled in the initial GLT. Each patient had laser treatment in one eye and medication in the other eye. The final results on 203 patients who were followed for an average of 7 years after treatment were reported in today’s American Journal& of Ophthalmology.
Researchers noted that both treatments caused side effects. However, the side effects of laser treatment were temporary or made no apparent difference in the long run, while the side effects of eyedrops were troublesome for some patients for as long as the drops were used. Eyedrops used for glaucoma treatment can cause discomfort in the eye, blurry vision, headaches, and fast or slow heartbeat.
In 34 percent of “laser first” eyes the laser treatment caused a temporary jump in intraocular pressure for the first few days after treatment. Also, some 30 percent of the “laser first” eyes developed peripheral anterior synechiae–adhesions that form when the iris sticks to part of the cornea. However, on all clinical measures, the eyes with adhesions were the same as eyes with no adhesions.
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- The Glaucoma Laser Trial (GLT) and Glaucoma Laser Trial Follow-Up Study: 7. Results. Glaucoma Laser Trial Research Group. Am J Ophthalmol. 1995 Dec. PubMed