Vent Incisions to Facilitate Peripheral Unfolding of the DMEK Graft

To present the results of 15 cases in which a modified technique of Descemet membrane endothelial keratoplasty (DMEK) with vent incisions was used to assist unfolding of tight peripheral inward folds.

This is a retrospective case series of 15 consecutive eyes that underwent a modified vent incision technique for DMEK. Six oblique, small-size (1 mm) vent incisions parallel to the limbus and 3.5 mm from the center were performed after descemetorhexis. The graft was opened with standard no-touch techniques and was partially attached to the stroma with air injection. Then, in cases with remaining tight inward folds despite gentle corneal tapping, jets of balanced salt solution were pulsed through the vent incisions directed at the peripheral folds to achieve complete unfolding.

Descemet membrane endothelial keratoplasty was performed in 2 phakic eyes (14%) and 13 pseudophakic eyes (86%). Six cases (40%) required fluid injection through the vent incisions: 3 corresponded to grafts from younger donors (54, 41, and 29 years old), and 3 had a 9.0-mm-sized graft. Complete graft unfolding was successfully achieved in 14 cases (93%), and in 1 case (7%), peripheral folds remained because of spontaneous bleeding in the anterior chamber. A clear cornea was achieved in all cases, and there were no postoperative complications associated with the vent incisions.

This technique provides a different DMEK no-touch approach that could be used in challenging cases of graft unfolding such as young donors and/or large-sized grafts. It may also avoid excessive unfolding times and direct manipulation that are related to higher endothelial cell loss.