DALK is a form of transplant surgery where the posterior surface of the patients own cornea is retained. This can mean quicker recovery times and less induced astigmatism post surgery. It also has the advantage of lower rejection rates as the tissue which causes rejection the endothelium is retained and not replaced with donor tissue. Usually an air bubble is injected into the cornea which splits the cornea into two at the level of the descement's membrane the anterior section is then discarded leaving only descemet's and the endothelium. The same is done with the donor, and unaffected by corneal distortion, cornea except that the anterior portion is then implanted onto the patients descement's membrane.
This procedure is only successful for those patient's where the corneal stroma is only minimally affected by the keratoconus. If there is deep scarring of the cornea especially down to descement's membrane then it is unlikely that there will be a positive outcome due to some of the scarring being retained with the posterior cornea.
For those cones that are suitable, this procedure is much more preferable to a full thickness cornea graft if only for the reason of a quicker recovery time. Patients are usually seeing improved vision after six to nine months as opposed to a full thickness graft which can take up to 18 months to fully recover any visual benefits. There is unfortunately still the possibility of contact lenses being needed for improved vision post-surgically, however, these can often be less complicated and more tolerable.
This procedure is only successful for those patient's where the corneal stroma is only minimally affected by the keratoconus. If there is deep scarring of the cornea especially down to descement's membrane then it is unlikely that there will be a positive outcome due to some of the scarring being retained with the posterior cornea.
For those cones that are suitable, this procedure is much more preferable to a full thickness cornea graft if only for the reason of a quicker recovery time. Patients are usually seeing improved vision after six to nine months as opposed to a full thickness graft which can take up to 18 months to fully recover any visual benefits. There is unfortunately still the possibility of contact lenses being needed for improved vision post-surgically, however, these can often be less complicated and more tolerable.