Diurnal IOP control with bimatoprost vs latanoprost in exfoliative glaucoma: a crossover observer-masked three- center study

Aim: To evaluate the diurnal IOP control and safety of bimatoprost versus latanoprost in exfoliative glaucoma (XFG). Methods: One eye of 129 consecutive XFG patients (mean age: 66.5±8.3 year) was included in this prospective, observer-masked, three-centre, crossover comparison. After a 4-6 week medicine-free period patients were randomized to bimatoprost, or latanoprost monotherapy for 3 months. Patients were then switched to the opposite therapy for another 3 months. At the end of the washout and the treatment periods diurnal IOP was measured at 8.00, 13.00 and 18.00. Results: At baseline IOP (mean±SD) was 28.0 ±4.0 mmHg, 26.9±3.6 mmHg and 25.9±3.6 mmHg, at the three time points, respectively. Both treatments significantly reduced mean diurnal IOP at month 3. Mean diurnal IOP was 26.9±3.5 mmHg at baseline, 17.6±3.3 mmHg with bimatoprost and 18.6±3.6 mmHg with latanoprost (p<0.0001). Furthermore, bimatoprost obtained lower IOP values at all time points (17.9±3.4 mmHg, 17.3 ±3.3 mmHg and 17.6±3.5 mmHg, respectively) compared with latanoprost (18.7±3.6 mmHg, 18.5±3.6 mmHg and 18.6±4.1 mmHg). The corresponding mean differences (0.8 mmHg, 1.1 mmHg and 1.0 mmHg, respectively) were all significant (p<0.001 for each comparison). Significantly more XFG patients obtained a target diurnal IOP<17 mmHg on bimatoprost than latanoprost, 55 (45%) vs. 34 (28%); (p=0.001), and significantly fewer patients were non- responders on bimatoprost than on latanoprost (5 vs. 13, p=0.021). More patients reported at least one adverse event on bimatoprost than latanoprost (58 vs. 41 at 3 months; p=0.0003). Conclusion: This crossover study suggests that bimatoprost obtains better diurnal IOP control than latanoprost in XFG.