Preparation of donor lamellar tissue for deep lamellar endothelial keratoplasty using a microkeratome and artificial anterior chamber system: Endothelial cell loss and predictability of lamellar thickness

BACKGROUND AND OBJECTIVE: To measure endothelial cell loss and predictability of lamellar thickness after preparing donor tissue for deep keratoplasty with an artificial anterior chamber and microkeratome. MATERIALS AND METHODS: A microkeratome set at a depth of 350 pm and a diameter of 9 mm was used to obtain ten lamellar lenticules from corneoscleral rims mounted in an artificial chamber. A punch trephine then was used to cut the donor tissue 7 mm in diameter. Specular microscopy was performed to evaluate endothelial cell density before the procedure, after cutting with the microkeratome, and after trephination. Pachymetry was performed to determine the predictability of lenticule thickness, before the procedure and after microkeratome incision. RESULTS: Mean post-microkeratome endothelial cell loss was 79 88 cells/mm(2) and post-punch trephination was 85 94 cells/mm(2). This represented a mean percentage loss of 3.2% and 3.5% for the respective steps of this procedure. Nine of the ten lenticules were cut within 75 mu m of the intended 350-mu m thickness. CONCLUSIONS: Preparing donor lenticules for deep lamellar endothelial keratoplasty with a microkeratome with artificial chamber system caused a relatively small loss of endothelial cells (6.7% of the total) and a reproducible thickness. This may have advantages over manual preparation techniques.