Endothelial lamellar keratoplasty using an artificial anterior chamber and a microkeratome

To compare postoperative astigmatic change and graft stability using 2 different donor button diameters in endothelial lamellar keratoplasty to treat corneal endothelial failure.

A 200- micro m-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.

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).

Both donor button sizes exhibited similar graft stability and astigmatic postoperative change in this experimental model.

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.