Comparison of IOP measurements pre-and post-photorefractive keratectomy using Pascal Dynamic Contour and Goldmann Applanation Tonometry

Purpose: To compare intraocular pressure (IOP) preoperatively and 6 months post-photorefractive keratectomy (PRK) using Pascal Dynamic Contour Tonometry (DCT) and Goldmann Applanation Tonometry (GAT). Setting: University of Ottawa Eye Institute (Ottawa, Ontario, Canada). Methods: Myopic patients undergoing PRK had IOP measured with DCT and GAT, as well as central corneal thickness (CCT) measurements at baseline and at 6 months post-surgery. A control group of age matched volunteers not undergoing surgery had similar measurements 6 months apart. Results: 10 patients undergoing PRK and 10 control patients were followed. IOP was not significantly changed in the PRK group pre-and postoperatively with DCT (p=0.4497) but decreased postoperatively with GAT (p=0.0042). CCT was decreased in patients undergoing PRK (p=0.0001). Conclusions: In patients who have undergone PRK, DCT measurements at 6 months postoperative are similar to preoperative indicating that this is a reliable method for tracking IOP in this group of patients. GAT significantly underestimated IOP postoperatively and therefore is not ideally suited for tracking changes in pressures post-PRK.