Reliability of Intraocular Pressure Measurement by Goldmann Applanation Tonometry After Refractive Surgery: A Review of Different Correction Formulas

Clin Ophthalmol. 2020 Sep 24:14:2783-2788. doi: 10.2147/OPTH.S263856. eCollection 2020.

Abstract

Myopia is one of the main risk factors for the onset of open-angle glaucoma. One of the first steps to assess glaucoma occurrence is the measurement of the intraocular pressure (IOP) by the Goldmann applanation tonometry (GAT). Even if this device is considered to be the gold standard for such measurements, it is affected by several sources of errors. Among these, there are the corneal thickness and curvature, both modified by corneal refractive surgery (CRS), that nowadays has become a very popular method to treat refractive errors. Indeed, CRS, by modifying the corneal shape and structure, causes an underestimation of the IOP measurements. In the literature, several IOP correction formulas to utilize with different devices have been proposed to overcome this problem. This paper aims to review the various correction formulas applied to the GAT in the attempt to improve the reliability of this measurement.

Keywords: GAT; IOP measurement; corneal refractive surgery; laser in situ keratomileusis; photorefractive keratectomy.

Publication types

  • Review

Grants and funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.