A meta-analysis of topical prostaglandin analogues intra-ocular pressure lowering in glaucoma therapy

OBJECTIVE: To compare the efficacy of latanoprost, bimatoprost and travoprost for lowering IOP in patients with glaucoma. RESEARCH DESIGN AND METHODS: In order to carry out this meta-analysis, randomized trials (2001-2004) were identified on Medline and EMBASE using the following key words: glaucoma, ocular hypertension (OHT), randomization, trial, latanoprost, bimatoprost and travoprost. The studies had to compare at least two prostaglandin analogues as mono-therapy. Cross-over experimental designs were excluded. The main outcome measure was IOP at final visit. Statistical analyses included random effects, pooled estimates of treatment effects, tests for publication bias, and random-effects models to obtain adjusted treatment effects on final IOP after lowering for baseline IOP, and duration of follow-up. Random effects Poisson regression models were used to estimate the adjusted effects of treatments on response rates (IOP < 18 mmHg). RESULTS: Nine studies were used in the analysis. Patient mean age varied from 56.7 to 68.8 years and baseline IOP ranged from 22.3 to 26.5 mmHg. Three hundred and seventy-eight patients were treated with bimatoprost, 385 with travoprost and 555 with latanoprost. Patients treated with travoprost and bimatoprost had lower IOP levels at the end of follow-up (-0.98 mmHg [95% CI: -2.08; 0.13; p = 0.08] and -1.04 mmHg [95% CI: -2.11;0.04; p = 0.06], respectively) than those treated with latanoprost. The combined effect of newer prostaglandin analogues (bimatoprost/travoprost) was an adjusted decrease of 1.00 mmHg [95% CI: -1.91;-0.10], p = 0.03], or a 17% higher adjusted response rate (Incidence Rate Ratio 1.17, 95% CI, 1.00-1.35, p = 0.04), compared to latanoprost. CONCLUSION: Travoprost and bimatoprost may have greater efficacy in lowering IOP for patients with OHT or glaucoma.