Monotherapy with latanoprost as effective as dual therapy, study says

European glaucoma treatment guidelines should be updated to reflect this finding, according to an investigator.

Issue: September 15, 2001

PRAGUE, Czech Republic — Monotherapy with latanoprost was an effective alternative to dual therapy with a beta-blocker and another drug in a study reported here.

Because of these results, it is time to change the glaucoma medical treatment guidelines established by the European Glaucoma Society (EGS), an investigator in the study said. The guidelines, which endorse adherence to beta-blocker-first medical therapy, are no longer valid given the treatment success now possible with other medications as monotherapy, he said.

“Our study showed that a dual therapy (with a beta-blocker) might be replaced by monotherapy with latanoprost eye drops, and therefore the treatment guidelines of the European Glaucoma Society should be modified,” said Lutz E. Pillunat, MD, speaking here at the International Glaucoma Symposium.

“I think that monotherapy should be the drug individually suitable for that individual patient and not just a recommendation with regard to one line of drug,” Dr. Pillunat said.

Guidelines for initial therapy

According to Dr. Pillunat, the current guidelines of the EGS call for use of a beta-blocker when glaucoma medical treatment is initiated.

“Their first guideline is that a topical beta-blocker should be initially selected as the intraocular pressure (IOP)-lowering agent of choice and be discontinued only if ineffective or if there are side effects,” he said.

“I think beta-blockers are not the only suitable drug for starting of monotherapy in glaucoma,” he stated. “Of course, our experience with them is very long, and they are still the gold standard in glaucoma therapy because the IOP-lowering is very effective. The treatment comfort is high, too, and there are different concentrations available. But in addition to lowering IOP, we have vascular risk factors and neurodegenerative aspects of the disease to be considered, as must be the well-known systemic side effects and contraindications of beta-blockers,” he said.

Dual therapy questioned

If monotherapy with a beta-blocker fails, the EGS guidelines say another agent should be added to the beta-blocker therapy, Dr. Pillunat said.

“If the monotherapy is not working, the EGS is recommending the combination of two drugs in cases of insufficient IOP control, visual acuity deterioration or if there are any adverse side effects,” he said.

He suggested that a switch therapy, instead of the additive approach, makes more clinical sense now that there are new, highly-effective medications such as prostaglandin analogues that for many patients have proven effective when used alone.

Latanoprost therapy alone is preferable to adding medication to sub- optimally controlled patients on a beta-blocker, he said.

Monotherapy appears equal

A European study was undertaken to demonstrate that the EGS guidelines need revising, Dr. Pillunat said.

“The purpose of our study was to evaluate whether treatment with monotherapy is comparable with respect to efficacy and safety with dual or combination therapy,” he said.

Patients in the study had unilateral or bilateral glaucoma. The controls were patients who remained on dual therapy.

“[A] major inclusion criterion was a medical treatment with two topical pressure-lowering drugs, and one of them had to be a beta-blocker and the pressure had to be controlled taking this kind of therapy,” he said.

Exclusion criteria included prior treatment with latanoprost and previous glaucoma filtering surgery.

“The study design was that patients on a dual therapy continued their dual therapy, and the other arm of the study was that patients on dual therapy were switched to latanoprost monotherapy,” he said.

The key outcome measure was that the pressure-lowering action of latanoprost monotherapy should be similar and equal to the continuous dual medical treatment.

“Due to a randomizing protocol, we had three times more patients on latanoprost than on the remaining dual therapy, but age, gender and diagnosis were otherwise similar between both arms of the study,” he said.

Results showed no major difference in the IOP control attained in either treatment group.

“The results were more or less comparable throughout the study; for the IOP, 83% fulfilled the criterion in the latanoprost group and 89% the dual therapy group. This difference was not statistically significant,” he stated.

There were no significant differences in systemic or ocular side effects.

There appeared, however, to be some difference in visual field parameters with less deterioration in the latanoprost group. “But on the other hand, the observed time of 3 months was not sufficient to really believe in a change of the visual field during that time period,” Dr. Pillunat noted.

The likely improved compliance resulting from monotherapy needs to be considered, too, he said.

For Your Information:

Lutz E. Pillunat, MD, can be reached at Universitat Klinikum Hamburg-Eppendorf, Martinstrasse 52, D-20246 Hamburg, Germany; (49) 40-428-03-3113; fax: (49) 40-428-03-2338. Dr. Pillunat has no direct financial interest in the products mentioned in this article.