Long-term course of surgically induced astigmatism after a 5.0 mm sclerocorneal valve incision.

Purpose: To study surgically induced astigmatism (SIA) after a sutureless 5.0 mm sclerocorneal valve incision. Setting: Department of Ophthalmology University of Vienna, Vienna, Austria. Methods: This study evaluated SIA in 34 cases of sutureless cataract surgery with a 5.0 mm superior sclerocorneal valve incision and implantation of a poly(methyl methacrylate) intraocular lens. Keratometry was measured with a Zeiss keratometer in all cases preoperatively, and 1 day, 1 week, and 3 months, and 1 and 5 years postoperatively. Results: Surgically induced astigmatism, calculated by Gravy's vector analysis, showed an initial mean with-the-rule shift of 0.35 diopter (D), followed by an against-the-rule shift to a mean of -0.30 D after 1 month. One year postoperatively, mean SIA was -0.46 D. Between 1 and 5 years postoperatively, there was a statistically significant increase in mean SIA calculated by Gravy's vector analysis, SIA increased from -0.46 D after 1 year to -0.76 D after 5 years postoperatively. Conclusion: A small, although statistically significant, amount of postoperatively induced astigmatism occurred 5 years after a sutureless 5.0 mm sclerocorneal valve incision.