OBJECTIVE: The purpose of the study was to evaluate the effect of trypan blue on intraocular pressure (IOP) after small-incision cataract surgery.DESIGN: Prospective, randomized study.PARTICIPANTS: Fifteen patients (30 eyes) with bilateral, dense, age-related cataracts.METHODS: Patients with glaucoma, ocular hypertension, exfoliation, pigment dispersion syndrome, history of uveitis, recent use of topical or systemic steroids, and previous ocular surgery were excluded. The patients were randomly assigned to receive trypan blue during cataract surgery for enhancing capsulorrhexis in 1 of their eyes, while in the other eye, trypan blue was not used. Cataract surgery was performed in an identical fashion in both eyes, with a sutureless posterior limbal incision, phacoemulsification, and implantation of a foldable intraocular lens. The same viscoelastic (sodium hyaluronate) was used in all cases and was thoroughly aspirated at the end of the procedure. All patients received a single dose of 250 mg acetazolamide 8 hours after surgery. No other antiglaucomatous agent was used during surgery or postoperatively. The intraocular pressure (IOP) was measured preoperatively and at 24 hours, 1 week, 1 month, and 3 months postoperatively.RESULTS: IOP values were similar in both groups at all 4 postoperative measurements. There was no statistically significant difference in postoperative IOP values between the eyes in which trypan blue was used and the control eyes.CONCLUSIONS: The use of trypan blue during small-incision cataract surgery does not have any effect on IOP during the immediate and early postoperative period.