Surgically induced astigmatism after superotemporal and superonasal clear corneal incisions in phacoemulsification

Abstract

Purpose: To evaluate surgically induced corneal astigmatism after small superotemporal and superonasal clear corneal incision cataract surgery. Setting: Department of Ophthalmology, School of Medicine, University of Afyon Kocatepe, Afyon, Turkey. Methods: This prospective study comprised 56 eyes of 28 patients who had bilateral phacoemulsification and implantation of a foldable intraocular lens (IOL) through a corneal tunnel incision. A superotemporal incision was used in all right eyes, and a superonasal incision was used in all left eyes. Topography was performed preoperatively and at 1 week, 1, 3, and 6 months, and 1 year. Surgically induced astigmatism (SIA) was calculated by vector analyses using the Holladay-Cravy-Koch method. The incision length was measured and was between 3.30 mm and 3.50 mm in all eyes. Results: Although SIA did not differ significantly between the 2 incision groups ( P>.05), decomposition of vectors showed that the horizontal component of SIA after superonasal incision was statistically significantly higher than superotemporal incision throughout the study ( P<.05). Vertical components of SIA and the incision size after IOL implantation with the syringe/cartridge system between the 2 incision groups were not significantly different ( P>.05). Conclusion: There was no statistically significant difference in SIA between superotemporal incisions in the right eyes and superonasal incisions in the left eyes 1 year after surgery for a surgeon who sits at the 12 o'clock. Superonasal clear corneal incisions can be used in left eyes and superotemporal clear corneal incisions in right eyes.