Randomised fellow eye comparison of the effectiveness of dorzolamide and apraclonidine on intraocular pressure following phacoemulsification cataract surgery

Purpose To compare the effectiveness of 2% dorzolamide and 0.5% apraclonidine on intraocular pressure (lOP) following phacoemulsification cataract surgery. Methods This prospective, randomised study comprised 54 eyes of 27 consecutive patients with age-related cataract scheduled for cataract surgery in both eyes. In each patient the eye with the higher degree of cataract was randomly assigned to receive one drop of either dorzolamide or apraclonidine immediately after surgery. The fellow eye was operated on later and received the other treatment. Cataract surgery was performed with a superior 6.0 mm sutureless frown incision, phacoemulsification and implantation of a three-piece PMMA intraocular lens. The lOP was measured pre- operatively as well as 6 h and 20-24 h and 1 week post-operatively. Results The mean pre-operative lOP was not significantly different between the groups (dorzolamide group, 14.9 ± 2.3 mmHg; apraclonidine group, 14.6 ± 2.5 mmHg; p = 0.450). At 6 h post-operatively, the mean lOP was significantly lower in the dorzolamide than in the apraclonidine group (15.6 ± 3.9 mmHg vs 18.0 ± 4.0 mmHg; p < 0.001). An lOP increase of more than 5 mmHg at 6 h post-operatively occurred in 3 (12%) eyes in the dorzolamide group and in 9 (36%) eyes in the apraclonidine group ( p = 0.034). At 20-24 h post-operatively and at 1 week post-operatively no difference was found between the groups. Conclusions 2% Dorzolamide is more effective than 0.5% apraclonidine in preventing the early post-operative lOP increase following phacoemulsification cataract surgery.