Effect of Corneal Curvature and Corneal Thickness on the Assessment of Intraocular Pressure Using Noncontact Tonometry in Patients After Myopic LASIK Surgery

Abstract

To evaluate the effect of corneal curvature and corneal thickness on the assessment of intraocular pressure (IOP) using noncontact tonometry (NCT) in patients after myopic LASIK surgery. All patients who had myopic LASIK in a university-based eye clinic between February 2002 and May 2002 were retrospectively analyzed. Preoperative NCT was compared with postoperative NCT, postoperative corneal thickness, and postoperative corneal curvature. The difference between the mean preoperative NCT (15.46 +/- 2.50 mm Hg) and postoperative NCT (6.30 +/- 1.57 mm Hg) was significant (9.16 +/- 1.96 mm Hg, P < 0.010). Preoperative NCT significantly correlated with postoperative NCT (P < 0.001), postoperative corneal thickness (P = 0.006), and postoperative anterior corneal curvature (P < 0.010). Both corneal thickness and anterior corneal curvature affect IOP assessment in patients with myopic LASIK. Although correction formulas can be used to estimate the actual IOP, alternative methods should be investigated to assess IOP independent of corneal thickness and curvature.