Effects of apraclonidine on intraocular pressure and blood-aqueous barrier permeability after phacoemulsification and intraocular lens implantation.

To evaluate the effect of topical apraclonidine on early postoperative intraocular pressure and blood-aqueous barrier permeability, we conducted a double-masked clinical trial in which 37 patients undergoing uncomplicated phacoemulsification and posterior chamber intraocular lens implantation were randomly assigned to treatment with 1% apraclonidine or its vehicle. One drop of 1% apraclonidine or its vehicle was instilled 1/2 hour preoperatively and immediately postoperatively. In addition to intraocular pressure, aqueous flare intensity was also determined before and after the operation by using a laser flare-cell meter. In the apraclonidine group, intraocular pressure showed no significant postoperative increase, whereas it showed a significant increase at six hours in the vehicle group (P < .01). Difference between intraocular pressure recorded at the end of the operation with the Tono-Pen II and that measured postoperatively was significantly greater in the vehicle group by 3.5 to 7.0 mm Hg (P < .05 to .01). In the apraclonidine group, the aqueous flare intensity was about half that in the vehicle group with significant differences at six (P < .05) and 24 (P < .01) hours.