In this six month prospective, parallel, randomised, investigator-masked clinical trial, 61 people with glaucoma were enrolled onto the trial, all of whom had previously been treated with timolol 0.5% used twice a day in both eyes. The patients were divided into two groups. In the first, the timolol treatment was replaced by bimatoprost 0.03% to be used once daily and in the second, latanoprost 0.005% (also to be used once daily) was added to the treatment regime. IOP measurements were then taken at days 15, 30, 60, 90, 120, and 180 with any topical side effects being recorded using digital colour photography.
It is interesting to note that of the 56 patients who were included for the 'intent to treat analysis' (28 people in each group) both treatment regimes lowered the level of IOP significantly at every visit (the baseline IOP was similar in both groups) and there was no statistically significant difference between them at any time in the study. However, there was a greater incidence of conjunctival hyperaemia, skin pigmentation and eyelash growth in the bimatoprost group than in the timolol and latanoprost group, whereas there was a greater incidence of headache in the timolol and latanoprost group than with bimatoprost.
The researchers concluded that 'Bimatoprost and the association of latanoprost plus timolol were equally effective in lowering the IOP in glaucomatous patients previously treated with timolol. Latanoprost plus timolol showed a better ocular safety profile.