Comparative study of three prostaglandin analogues in the treatment of newly diagnosed cases of ocular hypertension, open-angle and normal tension glaucoma.

Background: To compare the efficacy and tolerance of three prostaglandin analogues, bimatoprost, latanoprost and travoprost in patients with previously untreated open-angle glaucoma and ocular hypertension.

Methods: Prospective randomized single (investigator) masked comparative clinical trial at the Taunton and Somerset NHS Hospital, Taunton, UK. Newly diagnosed, treatment naïve glaucoma/ocular hypertension patients were recruited. Patients were randomized into three groups to receive one of the three prostaglandin analogues. Intraocular pressure (IOP) was measured before starting treatment and after 2 and 6 months of treatment. The IOP reduction and the tolerance profile of each drug were compared. The data were analysed on the basis of intention to treat, using analysis of covariance comparing IOP in the three groups at 2 and 6 months, adjusting for baseline IOP. Tolerance levels were compared using Kruskal-Wallis test.

Results: Of the 122 patients, 40 patients were given bimatoprost, 42 received latanoprost and 40 had travoprost. At 2 months, there was a significant difference between the three treatment groups (P = 0.013) with bimatoprost achieving a greater reduction in IOP than the other two drops. However, at 6 months, the difference was not statistically significant (P = 0.13). There was no significant difference in the tolerance profile.

Conclusion: All the three topical prostaglandin analogues are effective at lowering IOP, but bimatoprost was found to be most effective in the initial phase of the trial, and there was no statistically significant difference in the efficacy, among the three prostaglandin analogue eye drops after 6 months of treatment.