Evolution of deep anterior lamellar keratoplasty (DALK).

The concept of selective tissue transplantation was theorized over two centuries ago. However, deep anterior lamellar keratoplasty (DALK) was difficult to perform with the instruments available at that time, and visual acuity results were poor compared to those achieved by full-thickness transplantation. Recently, many technical improvements in surgical instrumentation and advances in eye bank technology have led to the re-emergence of DALK. Now, patients with stromal pathologies not affecting the corneal endothelium can benefit from this surgery, which allows total stromal replacement of the recipient's cornea, leaving an intact recipient Descemet membrane and endothelium. Along with the advances in surgical instrumentation, improvements in surgical techniques and imaging technology have contributed to improved visual outcomes obtained with DALK. DALK is now seen as a viable alternative to penetrating keratoplasty with equivalent visual results and better long-term graft survival.