Corneal topographic changes after frown and straight sclerocorneal incisions

To compare the corneal topographic changes following cataract surgery with two types of sclerocorneal tunnel incisions for implantation of 6.0 mm optic poly(methyl methacrylate) intraocular lenses.

University Eye Hospital, Vienna, Austria.

This prospective, unmasked, and unrandomized study comprised 48 otherwise healthy eyes scheduled for cataract surgery. A 4.5 mm sutureless frown incision was made in 22 eyes and a 6.0 mm straight sclerocorneal incision with a horizontal 10-0 nylon infinity suture in 26 eyes. Preoperatively and 1 week and 1 and 3 months postoperatively, corneal topography was recorded by the TMS-1 computer-assisted videokeratoscope (Computed Anatomy, Inc.). The data were evaluated by batch-by-batch analyses of the paired differences between the records. The significance of topographic changes was calculated by paired Wilcoxon tests; group comparisons were made using Wilcoxon tests.

In both groups, horizontal steepening and lower corneal flattening were consistently 0.4 diopter (D). Upper peripheral corneal flattening at 1 week and 1 and 3 months postoperatively was 0.7, 0.7, and 0.7 D, respectively, in the straight-incision group and 0.7, 0.4, and 0.3 D, respectively, in the frown-incision group. Vertical flattening and horizontal steepening were significant in both groups (P < .01). Group comparisons revealed significant differences in only 15 of 225 areas (P < .05).

There were no major differences between the two incision groups in surgically induced topographic changes.