Evaluation of a new system for obtaining donor lamellar grafts.

PURPOSE To evaluate the performance of a new system for obtaining corneal lamellar grafts of preset sizes. The system consists of the combination of an artificial anterior chamber (MALKS) and an automated microkeratotome (MASYK). METHODS A prospective study was performed. Lamellar tissue was obtained with the microkeratotome from 40 human corneoscleral buttons mounted in the artificial anterior chamber. The instrument was set to cut lamellae with a center thickness of 350 microm and a diameter of 10 mm. A new cutting blade for the microkeratotome was used for every 8 cases. Thickness was measured by ultrasound pachymetry. The lamellar diameter was assessed with a micrometric caliper. RESULTS The center thickness of the corneal lamellae ranged from 230 to 430 microm (mean, 322 +/- 48 microm; 95% confidence interval [CI], 307-337 microm). The diameter of the stromal ranged from 9.26 to 10.74 mm (mean, 10 +/- 0.27 mm; 95% CI, 9.9-10 mm). There were no cases of perforation or incomplete/irregular lamellae. The interface between the residual stroma and the lamellae was macroscopically smooth. The repetitive use of the same blade up to 8 times did not significantly change these results. CONCLUSION The MALKS and MASYK system showed good accuracy in obtaining lamellae of specific thickness and size taken from human corneoscleral buttons. It is a promising instrument for use in deep lamellar keratoplasty. The technique may be useful in obtaining precut lamellar donor tissue for distribution by eye banks.