Corneal shape changes after temporal and superolateral 3.0 mm clear corneal incisions

To compare the corneal topographic changes after temporal and superolateral 3.0 mm clear corneal incisions (CCIs) and implantation of foldable silicone intraocular lenses (IOLs).

Department of Ophthalmology, University of Vienna, Austria, and a private clinic, Winterthur, Switzerland.

This prospective study comprised 54 eyes of 54 patients scheduled for cataract surgery. After a 0.3 mm deep precut, a temporal 3.0 mm CCI was made in 26 eyes and a superolateral (at 10:30) 3.0 mm CCI in 28 eyes. Corneal topography was recorded preoperatively and 1 week and 1 and 3 months postoperatively using the TMS-1 computer-assisted videokeratoscope (Computed Anatomy, Inc.). Surgically induced corneal shape changes were evaluated by batch-by-batch analyses of the paired differences between the records. The significance of topographic changes was calculated by the paired Wilcoxon test; group comparisons were made using the Wilcoxon group comparison test.

Both groups had incision-related corneal flattening at 1 week and 1 and 3 months postoperatively. The extent of this flattening at 1 week and 1 and 3 months postoperatively was up to 1.0, 0.9, and 0.7 diopter (D), respectively, in the temporal group and up to 1.2 D at each observation time in the superolateral group. There was statistically significantly more incision-related corneal flattening in the superolateral incision group than in the temporal incision group; the difference was up to 0.3 D after 1 month and 0.5 D after 3 months.

The superolateral incision induced statistically significantly more incision-related corneal flattening than the temporal incision.