Epi–LASIK: Preliminary clinical results and histological findings of separated epithelial sheets

Abstract

Abstract: : Purpose: To evaluate the safe use of Centurion Epikeratome^TM and the preliminary clinical results of Epi–LASIK for the treatment of low myopia and myopic astigmatism. Methods: Epithelial mechanical separation was performed with the use of Centurion Epikeratome^TM (CIBA Vision Surgical, Duluth, GA) in 95 eyes of 52 patients with low myopia. The mechanically separated epithelial sheets were either preserved and reflected back in place after the photo ablation (Epi–LASIK group: 44 eyes of 32 patients) or were excised and underwent histological evaluation (51 eyes of 40 patients whose treatments were reversed to PRK). The preoperative spherical equivalent of Epi–LASIK group ranged from –1.75D to –7.00D and log MAR best spectacle corrected (BSCVA) from 0.10 to –0.10. Results: Epithelial separation was successfully performed in all 95 eyes. One eye did not receive laser treatment due to an uneven separation. In the Epi–LASIK group, the epithelial healing was completed within 4.87+0.56 days (range 3 to 5 days). The mean log MAR UCVA on the day of reepithelization was 0.20+0.09 (range 0.4 to 0.1). The spherical equivalent was –0.33D+0.75D (N=44) at one–month postoperative interval and –21+0.63 at three months postoperatively (N=32). 7 eyes (30%) gained one to two lines of BSCVA three months postoperatively. All Epi–LASIK treated eyes had clear corneas by the third postoperative month. The extend of trypan blue staining of the excised epithelial sheets (N=19) did not show any significant correlation with the clinical course of the operated eyes. Histological evaluation of separated sheets that were removed from the operative eyes 24 hours after the treatment (N=3) has shown that the separated sheet retained its normal stratification with a high percentage of morphologically viable epithelial cells. Conclusions: Preliminary clinical results suggest that Epi–LASIK is a safe and effective modality for the treatment of low myopia.

Keywords: laser • refractive surgery: other technologies • anterior segment