Natural course of intraocular pressure after cataract extraction and the effect of intracameral carbachol.

Intraocular pressure (IOP) is known to increase after intracapsular cataract extraction, extracapsular cataract extraction (ECCE), and ECCE with intraocular lens (IOL) implantation. Many pharmacological agents have been used to prevent this IOP rise. We conducted a two-phase, randomized, prospective study to evaluate the natural behavior of IOP after cataract surgery and the effect of intraoperative intracameral carbachol on it. In phase 1, 102 cases were randomly assigned to three groups for recording IOP at 24, 48, or 72 hours after ECCE. The IOP at 24 (mean 20.3 mm Hg) and 48 hours (mean 22.3 mm Hg) was significantly higher than the preoperative IOP (mean 16.1 mm Hg); 26.3% of cases in group 1A (24 hours) and 44.1% of cases in group 1B (48 hours) had IOPs greater than or equal to 25 mm Hg. In phase II, intracameral carbachol (0.01%) was used in 30 cases of ECCE and in 30 cases of ECCE with IOL implantation. The IOP at 24 hours (mean 16.3 mm Hg) was not significantly higher than the preoperative IOP and only 11.6% of the cases had IOPs greater than or equal to 25 mm Hg. The mean IOP at 24 hours without carbachol was significantly higher than the mean IOP at 24 hours with it. There was no statistically significant difference between IOP in the two groups one week after surgery.