Deep Anterior Lamellar Keratoplasty
A DALK Corneal Transplant, or Deep Anterior Lamellar Keratoplasty, is a surgical technique in which most of the cornea is replaced while preserving the thin posterior membrane of the eye known as the Descemet membrane and endothelium. This procedure can be a good option to consider when the innermost layers of the cornea are healthy, but the front most layers of the cornea are the problem. DALK tends to be more complex and difficult to perform when compared to other corneal operations since the surgeon is trying to preserve the innermost layer.
If the Descemet membrane is perforated during the operation, the surgeon must convert to a full corneal transplant or penetrating keratoplasty. DALK is an alternative to full thickness Penetrating Keratoplasty (PKP) and is indicated for the management of advanced keratoconus, corneal scarring, post LASIK ectasia, and endothelium spearing corneal dystrophies and degenerations. The procedure requires technical skill and involves dissecting the cornea to almost 95% thickness, and removing the top layer. A donor corneal button is prepared by removing Descemet’s membrane and donor endothelium. The donor graft is then stitched to the host. The cornea takes a little longer to clear but visual results can be similar to those of a penetrating keratoplasty.
The benefits with DALK can potentially include: fewer postoperative complications, less incidence of rejection, and shorter use of topical steroid treatment.