A 35-year-old male presents with advanced keratoconus, leading to significant visual impairment despite rigid gas permeable contact lens use. His corneal endothelium is healthy. Which of the following corneal transplant procedures would be most appropriate for this patient?

Explanation

Deep Anterior Lamellar Keratoplasty (DALK) is the most appropriate procedure for this patient. DALK is indicated for corneal stromal diseases with a healthy endothelium, such as advanced keratoconus, stromal dystrophies, and post-inflammatory scarring. It involves selective removal of the diseased corneal stroma while preserving the patient's own healthy Descemet's membrane and endothelium. This significantly reduces the risk of endothelial graft rejection, which is a major complication of full-thickness Penetrating Keratoplasty (PKP). PKP would be an option but carries higher risks. Descemet's Stripping Endothelial Keratoplasty (DSEK) and Descemet's Membrane Endothelial Keratoplasty (DMEK) are endothelial keratoplasties, indicated for endothelial dysfunction (e.g., Fuchs' dystrophy), not primarily stromal disease like keratoconus.