*Correspondence - Luis García-Onrubia: luis.garciaonrubia@gstt.nhs.uk

Purpose To describe a novel technique for deep anterior lamellar keratoplasty (DALK) in patients central corneal perforation and deep scarring making conventional DALK (Melles or Big Bubble) unviable. A posterior Descemet’s membrane (DM) skirt has provided an adequate scaffold for the migration of the host endothelial cells.

Methods and Analysis A case report. A 32-year-old male with previous hydrops developed severe corneal scarring with a break in DM visible on OCT scanning. A modified DALK procedure was perform consisting of a 400µm, 8.5mm Anterior lamellar cap with a 4.5mm posterior lamellar disc, denuded of endothelial cells and containing a DM skirt.

Initially, manual dissection of the and anterior 400µm of corneal stroma was performed using a modified Melles technique. The residual posterior lamellar was assessed and found to have significant residual scarring. A central 4mm optical window was performed through the posterior lamellar over the visual axis.

The donor tissue was cut using a 350µm microkeratome head. The anterior cap was trephined to 8.5mm and set aside. The posterior lamellar was placed in a punch block, and the endothelial was removed using a silicone tipped cannula. The removal of endothelial cells was confirmed using trypan blue dye. A posterior lamellar graft with a 4.0mm stromal bed and a 4.5mm DM skirt was fashion using a peeling and double punch technique. The posterior lamellar graft was inserted into the optical window such that the DM skirt provided a bridge to the donor corneal endothelium. The anterior cap was sutured with a double continuous suture of 10–0 monofilament nylon. An inferior peripheral iridotomy was created, and an air bubble filling the anterior chamber was left at the end of the case.

Results The preoperative visual acuity (VA) was hand movements. Full attachment of the posterior lamellar was seen at all time-points from week one onwards. Central corneal pachymetry continued to reduce for 12 weeks. One year after the operation, with sutures in, the best spectacle-corrected VA was 6/12. The corneal graft was clear, and no rejection episodes occurred. Endothelial cell repopulation of the donor DM could be observed with specular microscopy.

Conclusion The presence of DM promotes endothelial migration and healing. Modifications to traditional DALK surgery, in which DM is used to promote endothelial healing, are a viable alternative to penetrating keratoplasty. This method eliminates the risk of allograft endothelial rejection and allows a ‘regenerative’ for DALK to be used, offering a new modality of treatment in patients with healthy reserves of endothelial cells and deep posterior lamellar scarring.