THE EFFECT OF 1-PERCENT APRACLONIDINE ON INTRAOCULAR-PRESSURE AFTER CATARACT-SURGERY

BACKGROUND AND OBJECTIVE: To measure the effect of 1% apraclonidine hy drochloride eyedrops on intraocular pressure (IOP) after cataract surg ery. The effects of two different dosage regimens, once before surgery or once before and after surgery, were studied. PATIENTS AND METHODS: Patients scheduled for extracapsular cataract extraction and artifici al lens implantation were randomly assigned to three groups: group A h ad a placebo treatment (n = 18), group B had one drop of 1% apraclonid ine 1 hour before surgery (n = 16), and group C had one drop of 1% apr aclonidine 1 hour before surgery and 1 drop at the end of surgery (n = 17). Two percent hydroxy-propyl-methyl-cellulose was used as the visc oelastic substance. The preoperative IOP and the IOP 6 hours postopera tively in each patient were compared. The paired Student's t test was used to compare IOP before and after surgery. The study design was a r andomly assigned, double-masked, controlled clinical trial. RESULTS: I n group A (placebo) and group B (apraclonidine before surgery), there was a significant increase in IOP (mean IOP increase 11.2 +/- 9.9 mm H g SD, range -4 to 32, P = .00017, and 9.4 +/- 7.4 mm Hg SD, range -3 t o 24, P = .00014, respectively). In group C (apraclonidine 1 hour befo re and immediately after surgery), the increase in IOP was not signifi cant (mean IOP increase 5.1 +/- 11.5 mm Hg SD, range -10 to 28, P = .0 84). A postoperative IOP of more than 40 mm Hg applanation tension was reached by two patients in group A, one patient in group B, and two p atients in group C. CONCLUSION: Although 1% apraclonidine eyedrops ins tilled 1 hour before and immediately after extracapsular cataract extr action with artificial lens implantation may help prevent a statistica lly significant increase in IOP after the operation, 2 of the 17 patie nts still had IOPs greater than 40 mm Hg 6 hours postoperatively. Apra clonidine applied only before surgery did not prevent a statistically significant increase in IOP.