New Study Compares Side Effects and Effectiveness of Three Eye Pressure-Lowering Medications
Results of a 45-site U.S. study comparing three prostaglandin analogs, medications used to reduce intraocular pressure in people who have open-angle glaucoma or high intraocular pressure, will be presented at the 7th annual Association for Research in Vision and Ophthalmology meeting on May 4, 2003, in Ft. Lauderdale, Florida by the lead investigator, Richard K. Parrish, M.D., Professor of Ophthalmology at Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, and will appear in the May issue of the American Journal of Ophthalmology.
The study compared Xalatan® (latanoprost ophthalmic solution), Lumigan® (bimatoprost ophthalmic solution) and Travatan® (travoprost ophthalmic solution), and found no significant difference in effectiveness between the three treatments in reducing ocular pressure. However, patients using Xalatan were much less likely to develop redness and irritation of the eyes than those using either of the other two drugs.
“While prostaglandins are highly effective in the treatment of open-angle glaucoma, the data show Xalatan’s side effects profile is significantly better compared to other prostaglandins,” said Parrish. “This is important since side effects associated with this class of drugs, most specifically hyperemia and irritation, are significant barriers to patient compliance, and thus can result in treatment failure.” Ocular hyperemia is a bothersome side effect characterized by severe redness and irritation of the eyes.
According to study authors, the incidence of hyperemia reported by patients was 68.6% with Lumigan, 58.0% with Travatan and 47.1% with Xalatan over the 12-week study. According to the investigators’ assessment of the severity of hyperemia, the mean hyperemia score was lower (or milder) in patients taking Xalatan than in patients taking Lumigan at 2 and 12 weeks.
Glaucoma is a leading cause of blindness in the United Sates, especially for older people. Glaucoma is a family of more than 50 diseases that affects pressure within the eye, damaging the optic nerve. When pressure inside the eye increases, blind spots in peripheral areas of vision may occur. Often called the "sneak thief" of sight, most forms of glaucoma do not produce symptoms until vision is already severely damaged. But if diagnosed early, the disease can be controlled and permanent vision loss can be prevented.
Glaucoma affects approximately three million people in the United States and 67 million people worldwide. Open-angle glaucoma (OAG), a condition in which there is too much pressure in the eye is the most common form of glaucoma in the United States. In open-angle glaucoma, the optic nerve is slowly damaged, usually causing gradual loss of vision, and potential blindness. Both eyes can be affected at the same time, although one may be affected more than the other. Sometimes, much of the person's eyesight can be affected before he or she notices a change.
About The Study
This randomized, parallel-group, masked evaluator study was conducted at 45 U.S. sites. More than 400 patients, average age 65, participated in the study. All of the patients were diagnosed as having glaucoma or ocular hypertension (IOP>21 mm Hg at diagnosis) in one or both eyes and were currently or previously (within the past six months) being treated with monotherapy or dual therapy with a topical ocular hypotensive agent(s), to lower eye pressure. The primary intraocular pressure (IOP) measuring end point was 8 a.m., when patients experience higher IOP according to circadian patterns. Compared to Xalatan or Travatan-treated patients, a larger proportion of those treated with Lumigan reported an adverse event.
“As with any medication, compliance due to negative side effects is one of the biggest issues with treatment,” said Parrish. “For the most part, glaucoma is symptomless until significant damage has already been done. It’s difficult to convince patients to stay on a medication that makes them feel worse than the disease itself. People are more likely to stay on treatment with Xalatan because it works just as well as comparable treatments, yet causes significantly fewer side effects.”
Ophthalmic prostaglandin medications can slowly cause an increase in the amount of brown eye color, can darken eyelids and eyelashes, and increase the growth of eyelashes on the treated eye. Color changes can increase as long as Xalatan is administered and eye color changes are likely to be permanent. The most common side effects in eyes of patients treated with Xalatan for six months in clinical studies includes blurred vision, burning and stinging, eye redness, the feeling that something is in the eye, eye itching, darkening of eye color and irritation of the cornea, the clear front surface of the eye.
The research for this study was supported by a grant from Pharmacia Corporation.
About Bascom Palmer Eye Institute
Bascom Palmer Eye Institute has earned an international reputation as one of the premier providers of eye care in the world and its hospital has been ranked among the top two eye hospitals in the nation by U.S. News & World Report since 1991. It is the largest ophthalmic care, research and educational facility in the southeastern United States, ranking number one in patient care and residency training in Ophthalmology Times, and treating more than 180,000 patients each year with nearly every ophthalmic condition and performing more than 8,000 surgeries annually. With patient care facilities in Miami and Palm Beach Gardens, Bascom Palmer Eye Institute has served since 1962 as the Department of Ophthalmology for the University of Miami School of Medicine. For additional information about Bascom Palmer Eye Institute, please contact Marla Bercuson at 305-326-6190, or visit the website at www.bascompalmer.org.