Endothelial lamellar keratoplasty using an artificial anterior chamber and a microkeratome

Objective: To compare postoperative astigmatic change and graft stability using 2 different donor button diameters in endothelial lamellar keratoplasty to treat corneal endothelial failure. Methods: A 200-μm-thick corneal flap keratectomy was performed in human donor corneoscleral rims (n = 20; 10 donors and 10 recipients) using an artificial anterior chamber and a manual microkeratome (ALTK System; Moria USA, Doylestown, Pa). After flap reflection, stromal bed trephination was performed to obtain a disc consisting of posterior stroma, Descemet membrane, and endothelium. Host beds of 7.0 mm and 7.25-mm (n = 5) or 7.50-mm (n = 5) donor buttons were obtained using a freehand trephine. The graft was secured with 8 interrupted sutures (10-0 nylon) in the stromal bed. The flap was sutured with 3 interrupted sutures. Transplanted corneas were submitted to increasing intrachamber pressures to detect graft stability, and preoperative and postoperative videokeratographic data were recorded to assess astigmatic change. Results: The mean (SD) postoperative astigmatic change was 1.14 (3.17) diopters (D) in the 7.25-mm donor button group and 2.27 (1.77) D in the 7.50-mm donor button group (P = .69). Mean (SD) resisted pressures of 75.4 (44.81) mm Hg and 100.4 (46.86) mm Hg were observed in the 7.25-mm and 7.50-mm groups, respectively (P = .54). Conclusion: Both donor button sizes exhibited similar graft stability and astigmatic postoperative change in this experimental model. Clinical Relevance: As endothelial lamellar keratoplasty becomes further developed as a clinical alternative to penetrating keratoplasty, this laboratory model system should be useful in evaluating different mechanical factors that contribute to graft success.