Efficacy of brimonidine in preventing intraocular pressure spikes following phacoemulsification in glaucoma patients.

Purpose: To measure intraocular pressure (IOP) elevation 6 and 24 hours after phacoemulsification in patients with glaucoma and to investigate the efficacy of brimonidine tartrate 0.2% in preventing IOP rise on the first postoperative day following cataract surgery.

Methods: In this prospective randomized single-masked study, 86 eyes of 78 patients with well-controlled open-angle glaucoma were scheduled for phacoemulsification surgery. Patients were randomly assigned into 2 groups. Group A received 1 drop of brimonidine tartrate 0.2% and group B, which served as a control group, received 1 drop of artificial tears. Intraocular pressure was measured at baseline, before surgery, and 6 and 24 hours postoperatively.

Results: Within each group, we found a statistically significant difference in IOP between baseline and 6 hours postoperatively (p<0.01) and between 6 and 24 hours (p<0.01). There was no statistically significant difference between baseline IOP and 24-hour values. Comparing the 2 groups, there was no statistically significant difference in preoperative and 24-hour postoperative IOP. Six hours after surgery, the mean IOP in the brimonidine group was 18.52±4.58 mmHg, compared with 20.86±3.79 mmHg in the control group. Treatment with brimonidine tartrate 0.2% significantly reduced postoperative IOP elevation 6 hours following cataract extraction (p=0.009).

Conclusions: Patients with medically well-controlled glaucoma may experience a substantial increase in IOP shortly after phacoemulsification surgery. Instillation of brimonidine tartrate 0.2%, although it significantly reduced IOP elevation following cataract operation, did not completely prevent IOP spikes.