Analysis of Posterior Corneal Surgically Induced Astigmatism Following Cataract Surgery With a 1.8-mm Temporal Clear Corneal Incision

PURPOSE: To determine posterior corneal surgically induced astigmatism (SIA) when using a temporal clear corneal inci- sion and the IOLMaster 700 (Carl Zeiss Meditec AG) for bio- metric measurements and to determine whether posterior corneal SIA can be predicted from preoperative data.METHODS: A total of 258 consecutive eyes of 258 patients underwent cataract surgery with a 1.8-mm temporal clear corneal incision. Biometry measurements were taken pre- operatively and 6 weeks postoperatively using the IOLMaster 700. Using vector analysis, the SIA of the posterior cornea was calculated.RESULTS: The centroid of posterior corneal SIA was 0.01 di- opters (D) @159 & PLUSMN; 0.14 D. The mean posterior corneal SIA was 0.12 D & PLUSMN; 0.07 D. Posterior corneal SIA magnitude was 0.25 D or less in 95% of patients. There was no correlation found between posterior corneal SIA magnitude and any preopera- tive measurement.CONCLUSIONS: The authors suggest not adjusting for poste- rior corneal SIA if using a small caliber, temporal incision. It was not possible to predict posterior corneal SIA from preop- erative biometric measurements.