Deep anterior lamellar keratoplasty DALK is a partial-thickness corneal transplant that replaces the front layers of the cornea while preserving the patient’s own endothelium.
How DALK is performed
The surgeon removes diseased stromal tissue down to Descemet’s membrane. A matching donor layer is then sutured in place, leaving the inner cell layer intact.
- Used for conditions affecting the front cornea, such as keratoconus or some dystrophies
- Endothelial cells remain the patient’s own, reducing rejection risk
- Sutures are usually removed gradually over months
- Vision improves as the graft clears and the surface regularises
Benefits compared with full-thickness graft
Because the endothelium is preserved, long-term graft survival can be better. However, DALK is technically demanding and not suitable for every case.
- Lower risk of endothelial rejection and long-term failure
- Trauma is less likely to cause full-thickness wound rupture
- Some patients may still have residual irregular astigmatism
- Choice between DALK and PKP depends on disease depth and scarring
