When all else fails, corneal transplantation remains an excellent method for improving the vision in advanced cases of keratoconus. However it is only undertaken after ruling out other treatment options.
As an invasive surgical procedure, corneal transplant surgery does pose a small but potentially serious risk to the eye. There are several reasons to be cautious when deciding if a corneal transplant is a viable option
Traditional full thickness grafts are termed ‚ÄėPenetrating Keratoplasty‚Äô (PK). Such transplants carry a greater risk of complications such as graft rejection.¬† PK has limited lifespan and for the younger patient, the probability of rejection and failure is therefore greater and a second corneal transplant would be required.
The absence of blood vessels in the cornea means that the healing process is slow and it may take a year or even longer before the shape of the transplanted cornea (and effectiveness as a focusing lens) has stabilised.¬† During this time, vision in a transplanted eye would often not be functional.
A newer technique is a partial corneal graft, which is termed ‚ÄėDeep Anterior Lamellar Keratoplasty‚Äô (DALK). This is the preferred method for corneal transplantation. This technique has been practiced commonly for the last decade. It replaces the main structural layer (known as the stroma) but preserves the innermost layer of the cornea (known as the endothelium). This means that if initially successful, there is a very low chance of failure or rejection later on like PK.
There is a risk that even after absolutely perfect surgery, the healing process could be distorted causing the graft to become mis-shaped, creating abnormal astigmatism.