Influence of residual corneal bed thickness after myopic LASIK on intraocular pressure measurements

The purpose of this study was to compare the influence of residual bed thickness after myopic ablation on intraocular pressure measurements using Goldmann applanation tonometry and dynamic contour tonometry. Intraocular pressure using Goldmann tonometry and dynamic contour tonometry was measured in 50 eyes before, 1 and 3 months after LASIK for myopia. LASIK surgery reduced the central corneal thickness by 71 +/- 27 A mu m. During surgery, corneal thickness was measured by optical coherence pachymetry (Online OCP, 4optics AG) prior to flap creation, after flap lifting, and after laser ablation. Postoperative measurements with Goldmann tonometry were reduced by -3.7 mmHg (p < 10(-6)) and mean measurements with dynamic contour tonometry were reduced by -1.5 mmHg (p < 10(-6)). Differences in measurements with Goldmann tonometry were significantly correlated with thickness of residual bed after ablation, whereas measurements with dynamic contour tonometry were not. Thickness of residual bed appears to influence readings with Goldmann tonometry more than readings with dynamic contour tonometry after myopic LASIK.