Concordance between astigmatism values obtained using Javal’s rule and subjective refraction.

Abstract

<em><strong>Objective</strong><em> To assess the degree of concordance between astigmatism values obtained using Javal’s rule and subjective refraction in the student population of Pereira in 2012. <em><strong>Materials and methods</strong><em> This descriptive, correlational and cross-sectional study used the correlation-concordance coefficient (CCC) to establish the degree of astigmatism according to Javal’s rule and subjective refraction. In addition, patients were examined by using keratometry, meridian refraction, blurring, and astigmatic dial, in five-year age groups between 5 and 19 years of age. <em><strong>Results</strong><em> In total, 915 patients from Pereira were evaluated, 520 women and 395 men, with an average age of 11.53 years, and a standard deviation of 3.75. Expected concordance for continuous variables must be greater than 0.90 in order to be able to compare the values of subjective refraction and Javal’s rule. Nevertheless, a minimum value of 0.045 and a maximum value of 0.482 were found, which are lower than those required for concordance. <em><strong>Conclusions</strong><em> Javal’s rule is not a predictor that allows to correctly determine refractive astigmatism in patients, based on keratometry measurements.