Effect of capsulorhexis size on postoperative intraocular pressure

Objective: To determine whether capsulorhexis diameter has an effect on intraocular pressure (IOP) after phacoemulsification. Setting: SSK Ankara Eye Hospital, Ankara, Turkey. Methods: This prospective study comprised 58 patients selected for cataract extraction by phacoemulsification using a 5.2 mm temporal, clear corneal incision. Twenty-nine of 58 patients had a 4.0 mm capsulorhexis and the rest, 6.0 mm. Ail patients received a multipiece poly(methyl methacrylate) posterior chamber intraocular lens with a 5.0 mm diameter biconvex optic and flexible haptics. Followup was 3 months. Postoperative IOP was obtained by Goldmann applanation tonometry 1 and 2 days before surgery and 1 and 7 days and 1, 2, and 3 months postoperatively. Results: A significant decrease in IOP was observed in both the 4.0 and 6.0 mm capsulorhexis groups 1 day postoperatively (P < .0001 and P < .0001, respectively). At 3 months postoperatively, IOP decreased significantly over preoperative values both in the 4.0 mm (P < .0001) and 6.0 mm capsulorhexis (P = .0014) groups. There was a statistical difference between the mean 1 month IOP values in the 4.0 mm (11.34 +/- 2.18 mm Hg [SD]) and 6.0 mm capsulorhexis (13.00 +/- 2.30 mm Hg) groups (P = .0059). A statistical difference between the groups also existed at 3 months postoperatively (P = .0028). Conclusion: A 4.0 mm capsulorhexis resulted in lower postoperative IOP than a 6.0 mm capsulorhexis 1 month postoperatively.