The effect of acetylcholine on early postoperative intraocular pressure

We randomly assigned 36 patients undergoing extracapsular cataract extraction and posterior chamber lens implantation to two groups. The 18 patients in the treatment group received intracameral acetylcholine during the operative procedure, and the 18 patients in the control group received only balanced salt solution. In all other respects the patients were treated identically. Intraocular pressures were measured preoperatively, and at three, six, nine, and 24 hours postoperatively. Preoperatively, the mean intraocular pressures were 16.5 mm Hg in the treatment group and 16.8 mm Hg in the control group. Three hours postoperatively, the mean pressures were 11.9 mm Hg in the treatment group and 21.8 mm Hg in the control group. Six hours postoperatively the respective pressures were 15.4 mm Hg and 22.3 mm Hg. These differences in the mean pressures between the two groups were statistically significant. At nine and 24 hours postoperatively, the pressures in the treatment group remained lower than pressures in the control group, but these differences were no longer significant.