Effect of Corneal Astigmatism on IOP Measurement

Abstract

Abstract: : Purpose: To determine the effect of corneal astigmatism on IOP readings using a Goldmann's applanation tonometer. Methods: A total of 30 eyes of 22 adult patients who presented in clinical practise were selected. None of the eyes included had undergone previous intraocular surgery. Corneal curvatures were measured in the horizontal and vertical meridians and then applanation tension measured in the same order by rotating the prism through 90 degrees. Results: The IOP readings obtained were lower on the flatter axis in 50% of the cases but there was no statistically significant difference between the degree of corneal astigmatism and the variation in IOP measurements. Conclusions: There was no significant effect of corneal astigmatism on measurement of the IOP in the vertical and horizontal meridia.

Keywords: intraocular pressure • astigmatism • cornea: clinical science