Comparison of diurnal intraocular pressure control by latanoprost versus travoprost - Results of an observational survey

Background and objective: Intraocular pressure (IOP) is known to be subject to daily fluctuations, the occurrence of which is a risk factor for progression of glaucoma. Control of IOP during the day by drugs is an important therapeutic target. We set out to compare the IOP control of travoprost and latanoprost taking into account the time since last instillation and the time of IOP measurement. Methods: This was a prospective, cross-sectional observational study with some retrospective data collection. Private ophthalmologists were selected to each recruit ten patients with primary open-angle glaucoma and/or ocular hypertension receiving either travoprost or latanoprost as monotherapy. Clinical endpoints included IOP measurements and percentage of patients attaining predefined target IOPs. Six patient subgroups were defined according to: (a) IOP measurement time: before 1200h, 1200h-1600h and after 1600h, and (b) time since last intake (< 24 hours, > 24 hours). Analyses comprised chi(2) and Wilcoxon tests, A-NOVA, logistic regressions and adjustment by propensity score. Results: In total, 2052 patients treated with travorprost (n = 1704) or latanoprost (n = 348) participated in the study. Treatment groups were comparable at baseline, except for a longer treatment duration in latanoprost-treated patients. When the interval between the last treatment instillation and IOP measurement (treatment/IOP interval) was < 24 hours (n = 1241), 82% of travorprost-treated patients attained pre-defined target IOP versus 67% with latanorprost (p < 0.0001). This difference was greatest after 1600h, when the mean IOP was 16.5mm Hg for travorprost-treated patients and 17.7mm Hg for latanoprost-treated patients (p = 0.0025). When the treatment/IOP interval was > 24 hours (n = 461), travoprost was superior to latanorprost, i.e. more patients using travoprost attained the predefined target IOP (78.5% vs 68.3%; p = 0.0344), and the mean IOP value was lower in the travoprost group (16.8 vs 17.8mm Hg; p = 0.0016). After adjustments for confounding factors, similar results were obtained. Conclusions: According to this observational survey, travoprost appears to reduce evening and mean diurnal IOP more effectively than latanoprost. Latanoprost IOP control appears to be more sensitive to time since the last dose.