The comparative ocular hypotensive effect of apraclonidine with timolol maleate in exfoliation versus primary open-angle glaucoma patients

Purpose To compare the effect of adding apraclonidine 0.5% to timolol malea te 0.5% in patients with exfoliation versus primary open-angle glaucoma. Si nce exfoliation glaucoma is known to demonstrate higher pressures than prim ary open-angle glaucoma on timolol maleate therapy alone, the authors wishe d to determine whether apraclonidine equalised the intraocular pressure (IO P) between these two glaucomas when added to timolol maleate. Methods We age-matched 30 consecutive exfoliation and 30 primary open-angle glaucoma patients who had an IOP greater than or equal to 22 mmHg on timol ol maleate alone. Patients underwent IOP diurnal curve testing on timolol m aleate twice daily alone and, 2 months later, following the addition of apr aclonidine 0.5% three times daily. Statistical analysis of the IOP at each time point was by an unpaired t-test between groups. A paired t-test was us ed to evaluate the reduction in IOP from baseline within groups after the a ddition of apraclonidine. Results On timolol maleate alone, exfoliation patients had a higher mean IO P at 06:00 and 10:00 hours as well as a higher peak, range and standard dev iation of the IOP compared with primary open-angle glaucoma patients (p < 0 .05). Following the addition of apraclonidine the mean, peak and range of I OP were statistically similar between groups and only the standard deviatio ns remained higher in the exfoliation glaucoma group (p < 0.001). The mean diurnal IOP after apraclonidine was added was 20.5 +/- 7.0 mmHg in the exfo liation glaucoma group and 20.0 +/- 3.4 mmHg in the primary open-angle glau coma group, which was not significantly different between groups (p = 0.73) . Conclusions This study suggests that apraclonidine 0.5% used adjunctively w ith timolol maleate 0.5% solution is associated generally with similar IOP control in exfoliation and primary open-angle glaucoma patients.