Effect of Latanoprost on ocular hemodynamics and contrast sensitivity

Background. Latanoprost effectively lowers intraocular pressure. Because ischemia has gained increasing importance in the pathogenesis of glaucoma, an antiglaucomatous drug should also be investigated with regard to the influence on ocular hemodynamics. Methods. In a double masked, randomized, clinical trial, Latanoprost eye drops were administered to 15 volunteers once daily for 8 days and 15 further volunteers received placebo eye drops according to the same protocol. IOP, blood pressure, heart rate, ocular pulse amplitudes, pulse volume, pulsatile ocular blood flow and contrast sensitivity were measured before (1TO), 120 min after drop administration (1T120), after 7 days of therapy (8T0) and again 120 min after an acute administration (8T120). For statistical analysis a two-way variance-analysis and the t-test for paired samples were used. Results. IOP was found to be statistically significantly different comparing both groups over the test period (p=0.036). In Latanoprost-treated subjects the t-test revealed a significant drop in IOP between 1TO and 8T0 (p=0.009) and between 1T0 and 8T120 (p <0.0001). All other above mentioned parameters remained constant. Conclusion. In Latanoprost-treated subjects,a significant drop in intraocular pressure was observed after 1 week. However, ocular perfusion and contrast sensitivity did not change during therapy. This might be due to an effective autoregulation in healthy volunteers.