Corneal astigmatism after clear corneal and corneoscleral incisions for cataract surgery

Purpose: To compare the astigmatism induced by clear corneal incisions (CCIs) and corneoscleral tunnel incisions (CSIs) for cataract surgery over 6 months. Setting: Rotterdam Eye Hospital, Rotterdam, The Netherlands. Methods: Thirty-five patients having phacoemulification were recruited prospectively; 15 had CCIs and 20, CSIs. Corneal topography was performed by computerized videokeratoscopy preoperatively and 6 months postoperatively. The change in keratometric astigmatism was calculated using the absolute magnitude and vector analysis methods. Results: There was no significant difference between the change in astigmatism produced by the two incisions (Student's t-test). Conclusion: The CCI for cataract surgery did not produce significantly greater astigmatism than the CSI. Concern over CCIs having a greater risk of increasing corneal astigmatism is unfounded and does not justify withholding the technique from patients it could benefit.