Comparison of efficacy of four prostaglandin analogues by bilateral treatment in healthy subjects.

PURPOSE

To compare the drug efficacy of four prostaglandin analogues (PGAs) by bilateral treatment in normal subjects.

METHODS

Three consecutive studies comparing latanoprost to three other PGAs (travoprost, tafluprost and bimatoprost) were performed in 24 healthy subjects. Each study was separated by a washout period of over 6 weeks. In each study, two drugs were randomly assigned to one eye of each subject. Study subjects instilled the assigned medication at 9:00 p.m. every day for 2 weeks. The same masked investigator measured intraocular pressure (IOP) at 9:00 a.m., 1:00 p.m. and 5:00 p.m. at baseline and repeated measurements on days 7 and 14. The differences in IOP reduction were compared between the drugs.

RESULTS

Mean diurnal IOP reduction with latanoprost on days 7 and 14 was similar to that with travoprost and tafluprost, but was significantly lower than that with bimatoprost. The association of the mean diurnal IOP reduction between latanoprost and bimatoprost on day 14 (r (2) = 0.25) was weak, in remarkable contrast to the strong association between latanoprost and travoprost (r (2) = 0.81) and between latanoprost and tafluprost (0.82).

CONCLUSIONS

The short-term bilateral treatment revealed a different IOP-lowering efficacy of bimatoprost compared to other PGAs in healthy subjects.