INTRAOCULAR-PRESSURE ELEVATION AFTER SIMPLE PARS-PLANA VITRECTOMY

Purpose: The purpose of the study is to determine the incidence, timin g, and severity of variability in the intraocular pressures (IOPs) fro m baseline after simple pars plana vitrectomy. Methods: A prospective study was performed in 25 consecutive patients undergoing simple pars plana vitrectomy. Intraocular pressures were measured before surgery, immediately after surgery, and then at 2, 4, 6, 12, and 24 hours after surgery. Results: The mean IOP was elevated significantly 2 hours aft er surgery when compared with the mean immediate postoperative IOP (30 .3 mmHg +/- 11.0 mmHg vs. 17.4 mmHg +/- 7.0 mmHg, P < 0.001). A steady decline was seen at all succeeding timepoints. The 24-hour mean (17.3 mmHg +/- 4.3 mmHg, P = 0.923) was similar to baseline. Ninety-two per cent of eyes had a 2-hour postoperative IOP that was higher than the I OF at the completion of surgery. Forty percent of patients required me dical management for IOP greater than or equal to 30 mmHg. Conclusions : Significant IOP elevation can occur after simple pars plana vitrecto my. The optimal time for detecting the pressure rise during the first 24 hours is 2 hours after surgery.