Comparison of Goldmann Applanation Tonometry and Dynamic Contour Tonometry in the Measurement of Intraocular Pressure in Eyes with Different Corneal Thicknesses

Abstract

Purpose: To compare Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT) in the evaluation of intraocular pressure (IOP) in eyes with different corneal thicknesses. Methods: GAT and DCT were performed in 70 eyes of 35 subjects aged between 21 and 59 years. Thirty eyes had normal, nonoperated corneas and 40 eyes had reduced central corneal thickness (CCT) following myopic photorefractive keratectomy. The GAT and DCT values were correlated to CCT and age and the agreement between both tonometers was determined by the Bland and Altman method. Results: GAT correlated strongly with CCT (p = 0.0002), but there was no correlation between DCT and CCT (p = 0.4388). No correlation was found between IOP values obtained with both devices and age. The Bland and Altman plot evidenced a lack of agreement between both tonometers with 95% limits of agreement between 1.6 and –5.6 mm Hg. Conclusions: GAT gives significantly lower values in the eyes with thin corneas and DCT is not influenced by CCT. DCT could be recommended to evaluate IOP in eyes with out-of-range corneal thickness.