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What if I have already had a corneal transplant?

Corneal transplants are often used in advanced cases of keratoconus when the cornea is scarred and vision is no longer correctable to an acceptable level of visual acuity. Most cases of keratoconus never reach the severity level of needing a corneal transplant. However, when a corneal transplant is needed, the final visual outcome could take months or even years to reach. Corneal transplants are sometimes needed for other corneal conditions or dystrophies not related to keratoconus. Injuries to the corneal or corneal infections and ulcers can also permanently scar the cornea resulting in the need for corneal transplantation.

A corneal transplant is a very delicate surgery in which the diseased cornea is removed and is replaced with a cornea from an organ donor. Since the corneal is avascular (no blood vessels), the cornea from the donor does not have to be a genetic match as in other organ transplants. However, in about 10% of corneal transplants, abnormal blood vessels will grow into the donor cornea allowing an immune system response and rejection of the donor cornea. This will require the procedure to be repeated.

During the corneal transplant, the surgeon will physically stitch the donor cornea to the remaining non-diseased cornea. Although the surgeon’s hands are very skilled in this delicate task, no transplant is perfect. Ever stitch has to be balanced with the stitch on the opposite side of  the cornea or the tissue will be “tugged” toward one side of the cornea resulting in an uneven cornea and high amounts of irregular astigmatism.  A good analogy to this procedure would be a trampoline. Similar to the stitches in a transplant, all the springs of a trampoline must be properly in place and balanced or the trampoline will be unbalanced and wrinkled.

Since no corneal transplant is perfect, some sort of vision correction is almost always needed after surgery and can very greatly in severity. In rare cases, glasses corrections can be used to improve clarity of vision to an acceptable level.  However, in most cases, the stitching and uneven healing of the transplant will induce irregular astigmatism which cannot be corrected with glasses or contact lenses.  The transplant can also produce a very steep corneal surface which can make contact lens fitting difficult.

The best way to maximize vision and comfort in post corneal transplants is the use of scleral contact lenses. These lenses will completely cover the uneven donor cornea giving it a  smooth optical surface and much better clarity than other correction options. Dry eye can also be a significant problem in post transplant patients. Scleral lenses offer an excellent barrier to tear evaporation and relief from dry eye issues.