What is DSAEK? DSAEK is a form of corneal replacement that replaces only the inner layers of the cornea. To understand DSAEK one needs to understand the structure of the cornea. The cornea is the round, transparent dome on the front of the eye and covers the eye in much the same way that a watch glass covers the surface of a watch. It is curved and smooth. The cornea is made up of three layers, much like an Oreo cookie. There is an outer wafer, and thick inner filling and an inner wafer. A corneal transplant replaces some or all of the layers of the cornea. Until a few years ago, in fact, there was only one good choice and that was to remove and replace all layers of the cornea. This was done with a circular blade, like a tiny cookie cutter that would cut out a disc of the central cornea to be replaced by a donor.

However, people that require a corneal transplant may only have problems with one layer, commonly the inner layer or wafer. This can occur as a result of an aging process called Fuchs’ dystrophy, can result from an injury or following eye surgery. A regular corneal transplant works well for these conditions, but does have its problems. The cornea can be not smooth and irregular following a transplant, having what we call astigmatism. This can be caused by the tension on the stitches that hold the transplant in place. Also, a regular corneal transplant takes a long time to heal, a year or more. During this healing time, the vision can be poor.

With DSAEK, the process is much smoother and quicker. Usually only one stitch is needed to close the incision. Just the inner wafer of the cornea is removed by peeling it off, like a postage stamp. A donor wafer is prepared from a donated cornea. This is done with a machine called a microkeratome that can precisely slice a very thin layer off the top of the cornea, leaving us with the inner layer to be used for transplantation. This layer is a thin as a soft contact lens and is flexible. We carefully fold it and insert it into the eye and attach it to the back of the dome of the cornea, like inserting a piece of cellophane inside a watch glass and sticking it to the back of the glass. The new wafer is held in place with an air bubble until it adheres. This usually takes 24 hours. In some cases the new cornea disc does not stick the first time, and then another air bubble is place to air in the attachment. So instead of 16 to 32 stitches used in a regular corneal transplant, only one is used. People start to recover vision in a week or so, and usually by 3 months, the vision is quite good following DSAEK.

DSAEK is really a marvelous innovation and offers people a chance to have a much less complicated procedure and retain most of their own cornea. It is truly a modern medical wonder.