Opposite Clear Corneal Incisions versus Steep Meridian Incision Phacoemulsification for Correction of Pre-existing Astigmatism.

Purpose: 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.

Methods: 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.

Results: 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.

Conclusion: 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.