Long-term astigmatic changes after clear corneal cataract surgery

Purpose: To assess long-term astigmatic changes after clear corneal cataract surgery. Setting: Stadtisches Klinikum, Augenklinik, Karlsruhe, Germany. Methods: We evaluated the first 100 of 2800 patients having cataract surgery with a superior or lateral corneal self-sealing incision and implantation of a 5.0 mm poly(methyl methacrylate) intraocular lens. Surgically induced astigmatism (IA) and absolute astigmatism (AA) were evaluated after 1 week and 1 and 2 years using keratometry and corneal topography. Statistical analysis was done using the Wilcoxon signed-rank test. Results: In eyes with a 12 o'clock incision (n = 50), the mean IA was 1.18 diopters (D) +/- 0.79 (SD) after 1 year and 1.53 +/- 0.95 D after 2 years. In eyes that had with-the-rule astigmatism preoperatively (n = 15), the mean AA was 0.62 +/- 0.57 D after 1 year and 0.93 +/- 0.56 after 2 years. In eyes with lateral incisions (n = 50), the mean IA was 0.96 +/- 0.74 after 1 year and 0.64 +/- 0.50 after 2 years. In eyes with against-the-rule astigmatism preoperatively (n = 15), the mean AA was 0.66 +/- 0.70 after 1 year and 0.52 +/- 0.65 after 2 years. The between-group difference in astigmatism after 2 years was statistically significant. Conclusion: The 12 o'clock incision was associated with a statistically insignificant increase in AA 2 years postoperatively and the lateral incision, with a statistically significant decrease. We currently recommend routine use of clear corneal incisions in cataract surgery.