Microkeratome versus femtosecond laser predissection of corneal grafts for anterior and posterior lamellar keratoplasty

PURPOSE: To compare 2 different techniques for predissection of human anterior and posterior lamellar corneal grafts for eye bank storage. METHODS: A mechanical microkeratome (group 1, N = 5) and a femtosecond laser (group 2, N = 5) were used to dissect intended 350-μm-deep lamellar planes in deepithelialized donor corneas mounted on an artificial anterior chamber. These corneas were replaced in Optisol GS at 4°C postoperatively and examined 2 days later to simulate a clinical scenario. Ultrasonic pachymetry of corneal lamellar sections was measured before and after separation of the lamellar grafts. Group 1 sections were separated by the mechanical microkeratome, whereas group 2 sections were manually separated 2 days after laser dissection. Endothelial cell viability was evaluated in posterior grafts. RESULTS: Total corneal thicknesses immediately before dissection were 559 ± 61 (group 1) and 578 ± 79 μm (group 2; P = 0.46). Immediate postdissection anterior and posterior graft thicknesses were 361 ± 68 and 203 ± 74 μm (group 1), respectively. Achieved anterior and posterior graft thicknesses 2 days later were 282 ± 44 and 413 ± 35 μm (group 1) and 324 ± 112 and 397 ± 51 μm (group 2), respectively. Percentage of devitalized endothelial cells were 3.4% ± 1.6% (group 1) and 1.6% ± 1.2% (group 2; P = 0.35). CONCLUSIONS: Centralized predissection by both techniques, cold storage, and shipping by airmail results in viable grafts without significant endothelial cell loss 2 days later.