RESUMEN
To compare the efficacy of adding an opposite clear corneal incision [OCCI] on the steep meridian versus performing surgery on the steep meridian alone during phacoemulsification in reducing pre-existing corneal astigmatism. This randomized clinical trial was performed on 120 eyes with corneal astigmatism of > 1D undergoing phacoemulsification. Incisions were made based on the type of astigmatism as follows: superior or superior + OCCI for with-the-rule and temporal or temporal + OCCI for against-the-rule astigmatism. Patients were followed with refraction, keratometry and topography. Statistical analysis was performed using one- and two-way ANOVA and Tukey-a test. Mean corneal astigmatism was 1.82 +/- 0.86 D in the superior + OCCI group and 1.74 +/- 0.86 D in the temporal + OCCI group preoperatively which decreased to 1.31 +/- 0.59 [P=0.013] and 1.19 +/- 0.64 [P=0.009] postoperatively respectively. No significant change occurred in the amount of astigmatism in any of the two single incision groups. Paired OCCI on the steep axis is a useful technique to correct mild to moderate pre-existing astigmatism with no need for particular skill or additional instruments