[New automated microkeratome for trepanation of lamellar keratoplasty]. / Neues automatisiertes Mikrokeratom zur Trepanation lamellärer Keratoplastiken. Erste Erfahrungen.

ABSTRACT

BACKGROUND/PURPOSE: Lamellar keratoplasty is an established therapy of corneal pathologies without endothelial involvement and the lack of endothelial rejection is one of the major advantages compared to penetrating keratoplasty. The major disadvantages of manually prepared lamellar corneal grafts are the limited mechanical and optical quality but the automated lamellar therapeutic keratoplasty system ALTK (MORIA) is intended to overcome these disadvantages. The purpose of this preliminary work is to investigate histologically and in clinical cases, if the ALTK system can achieve this aim. PATIENTS AND METHODS: Corneas from two human donors were cut with a 300 microns trephine. After fixation, the stromal bed and the excised cup of one specimen were stained with PAS and examined by light microscopy and the other specimen was analyzed by scanning electron microscopy. In addition, follow-up data of two patients who received such a lamellar graft are reported for the first 9 and 7 months postoperation, respectively. RESULTS: The lamellar cut of homogeneous depth revealed only minor stromal trauma. Both clinical cases demonstrated only minimal interface haze during follow-up. Despite a remarkably clear cornea, visual acuity improved only slowly because the precise lamellar cut tended to partially reproduce any preexisting irregular astigmatism. CONCLUSIONS: The ALTK system simplifies and standardizes the trephination of lamellar corneal grafts but a longer follow up is necessary with respect to visual development and preservation of a clear graft.