Medically reviewed by Dr. Niranjana Bejan Singh. Written to established clinical-education standards (AAO/Mayo/NHS/NEI) and adapted for this hospital. Not a substitute for professional medical advice.
DALK is a partial-thickness corneal transplant that replaces the outer and middle layers of a diseased cornea while preserving the patient's own healthy innermost layer, called the endothelium. It is commonly used for conditions such as keratoconus or corneal scarring that spare the endothelium, and it carries a lower risk of the most serious type of graft rejection compared with a full-thickness transplant.
Who typically needs this
- People with keratoconus whose endothelial layer remains healthy but who need more correction than cross-linking alone can provide.
- Corneal scarring from injury or infection that is limited to the outer and middle layers of the cornea.
- Certain corneal dystrophies that spare the innermost cell layer.
- Not suitable when the endothelium itself is diseased or damaged, since DALK does not replace that layer.
What to expect
- The surgeon carefully removes the diseased outer and middle layers of the cornea, leaving the healthy inner layer intact.
- Matching donor corneal tissue, with its own endothelium removed, is placed over the remaining layer.
- The graft is secured in place with fine sutures.
- The eye is protected with a shield after surgery, and healing is monitored at subsequent visits.
Recovery
- Vision recovery is gradual, with sutures typically remaining in place for many months.
- Regular follow-up appointments track graft healing and adjust sutures as needed.
- Anti-inflammatory eye drops are used for an extended period, though generally for a shorter time than after a full-thickness transplant.
- Activity restrictions during healing are similar to those after a full-thickness corneal transplant.
Risks to know about
- A recognized surgical challenge is a small perforation of the deepest corneal layer during the procedure, which can require converting to a full-thickness transplant.
- Some residual haze or irregularity at the junction between donor and host tissue can affect final vision quality.
- Astigmatism from the healing wound is common and often needs correction with glasses or contact lenses.
- Rejection of the transplanted outer layers can still occur, although it is less common and usually less severe than after a full-thickness transplant.
Frequently asked questions
How is DALK different from a full corneal transplant?
DALK keeps the patient's own innermost corneal layer in place, which lowers the risk of the most serious type of graft rejection.
Why might a surgeon switch to a full-thickness transplant during DALK surgery?
If the deepest corneal layer is accidentally perforated during the delicate separation of layers, completing a full-thickness transplant instead is sometimes the safer option.
Is recovery faster than with a full-thickness transplant?
Recovery timelines are broadly similar, though rejection-related complications are generally less common with DALK.
Who is a better candidate for DALK rather than DSEK/DMEK?
DALK is used when disease affects the outer corneal layers, while DSEK/DMEK is used when the innermost layer itself is diseased.
Ready to see us?
Call the appointment desk, or book online — we will confirm your time by phone.
Sources consulted: AAO — About Corneal Transplantation, Mayo Clinic — Cornea transplant . General medical information — not a substitute for professional diagnosis. Medically reviewed by Dr. Niranjana Bejan Singh.
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