Bandage lamellar-optical keratoplasty for post-excimer laser keratectasia

Abstract

Introduction. According to various sources, occurrence rate of keratectasia (KE) after Laser in situ Keratomileusis (LASIK) ranges from 0.04 to 0.2%. No known technique for keratorefractive surgery eliminates the probability. Neither corneal cross-linking, nor implantation of polymeric segments can completely prevent its development. Purpose — to treat KE after LASIK with bandage lamellar-optical keratoplasty (BLOK) surgery and to evaluate the results. Material and methods. The study included 22 patients with KE after LASIK divided into two groups. The first group consisted of 6 patients; they underwent BLOK surgery using a segment transplant 1.5 mm in width and 180—220 μm in thickness. The second group included 16 patients who underwent BLOK surgery using 2.75 mm wide, 290—350 μm thick allogeneic transplant of individual length. The follow-up lasted 4 years. Results. In the first group, uncorrected visual acuity (UCVA) improved by 0.4±007, in the second group — by 0.46±0.15. After two years, two patients had their transplant exchanged for a wider one due to ectasia progression. Corneal refraction was stable at 45.36±1.47 Diopters in all other patients of the first group. In the second group, it was consistently between 40.6 and 45.7 Diopters. The main complication of the BLOK surgery was displacement of the edge of the corneal flap formed during LASIK — occurred in 4 patients. Conclusion. Bandage lamellar-optical keratoplasty proved effective in treating patients with KE after LASIK, leading to improvement of visual acuity, strengthening of the cornea and normalization of its surface; it slows further progression of ectasia.