COMPARISON OF THE UNIVERSALKERATOME AND THE AUTOMATED CORNEAL SHAPER

Purpose: To compare the morphologic appearance and measurements of in situ keratomileusis performed with the UniversalKeratome(TM) (UK) with those done with the Automated Corneal Shaper (ACS). Setting: Surgical suite within private practice. Methods: Procedures were performed the same day on mate eye-bank eyes. In situ keratomileusis was done using existing nomograms for each instrument to resect a cap thickness of 1 60 mu m and a myopic resection of 100 mu m. Intraocular pressures were increased by inflating the globes with balanced salt solution and wer e measured with the suction fixation rings in place. The excised caps and stromal resections were measured twice independently after surgery , again after tissue fixation, and then evaluated with light and scann ing electron microscopy. Results: No complications were encountered. C ompared with the ACS, the UK was easy to set up, use, clean, and take down. Its excised tissue dimensions were greater and more predictable, it resected a concave shaped lenticule (edges imperceptibly blending with the host stroma), and it created a smoother power resection surfa ce and primary resection base. Conclusions: Smoother, predictable tiss ue resection, and simple assembly/disassembly and use give the UK an a pparent advantage over the ACS. The UK corrects astigmatism and hypero pia by changing the shape of the poly(methyl methacrylate) optical ins ert.