Comparison of Intraocular Pressure before and after Laser in Situ Keratomileusis Measured with Applanation Tonometry, Non Contact Tonometry and Rebound Tonometry

Abstract

Measurement of intraocular pressure (IOP) plays a central role throughout ophthalmology. It is part of routine ophthalmologic examinations and important in the management and follow-up of patients with glaucoma. While elevated IOP remains the most important risk factor for development and progression of open angle glaucoma, at least half of the population diagnosed with open angle glaucoma is asymptomatic. There are many types of tonometry like Goldmann applanation, Perkins, NCT, ORA, Schiotz, Pneumotonometry, Tonopen, Rebound and DCT. Numerous studies have documented a change in measured intraocular pressure (IOP) after LASIK, PRK, and other refractive surgeries. The aim of our study is to compare the accuracy of intraocular pressure measurement before and after LASIK surgery using three different types of Tonometers: Applanation tonometry, Non contact tonometry and Rebound tonometry, considering the change in the central corneal thickness. In this study 80 eyes of 40 patients with mean age of 27±6 years were scheduled for LASIK.CCT before and after surgery was obtained by US pachymetry.IOP values were measured before and after surgery using three different types of Tonometers: Applanation tonometry, Non contact tonometry and Rebound tonometry.