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

To study surgically induced astigmatism (SIA) after a sutureless 5.0 mm sclerocorneal valve incision.

Department of Ophthalmology, University of Vienna, Vienna, Austria.

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, 1 and 3 months, and 1 and 5 years postoperatively.

Surgically induced astigmatism, calculated by Cravy'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 Cravy's vector analysis; SIA increased from -0.46 D after 1 year to -0.76 D after 5 years postoperatively.

A small, although statistically significant, amount of postoperatively induced astigmatism occurred 5 years after a sutureless 5.0 mm sclerocorneal valve incision.