Change in Intraocular Pressure Measurement After Myopic LASEK: A Study Evaluating Goldmann, Pascal and Applanation Resonance Tonometry

Purpose: To prospectively evaluate 3 tonometry methods-the gold standard, Goldmann applanation tonometry, a new method, Pascal dynamic contour tonometry (PDCT), and a method under development, applanation resonance tonometry (ART)-with respect to intraocular pressure (IOP) measurements before, 3 and 6 months after laser-assisted subepithelial keratectomy (LASEK). Materials and Methods: One randomly assigned eye of each of 53 healthy individuals, who underwent LASEK surgery for myopia was studied. Visual acuity, central corneal thickness, corneal curvature, and IOP were measured at each visit. Six IOP measurements/methods with 5 minutes pause between methods were performed. Results: All tonometry methods measured a significantly lower IOP after LASEK correction by a mean of -3.1 diopters. The IOP reduction was largest after 6 months for Goldmann applanation tonometry (-1.7 +/- 1.8mm Hg) followed by ART(stat) (-1.2 +/- 1.5mm Hg), PDCT (-1.1 +/- 1.6mm Hg), and ART(dyn) (-1.0 +/- 1.5mm Hg). The reduction of IOP did not differ significantly between different methods (P = 0.11). There was a significant further reduction of measured IOP for PDCT between 3 and 6 months (-0.5 +/- 1.0mm Hg). Uncorrected visual acuity improved significantly between 3 and 6 months postoperatively from 1.32 +/- 0.28 to 1.43 +/- 0.27. Conclusions: All tonometry methods measured a significant, but low, reduction of IOP 3 and 6 months after LASEK. Further change in visual acuity and IOP measurements between 3 and 6 months suggest a still ongoing postoperative process.