Penetrating Keratoplasty (PKP)
In PKP, the surgeon removes the window of cloudy tissue from the patient's cornea and replaces it with donated tissue. This new tissue is held in place with many tiny stitches. To allow healing, these stitches must remain in place for at least six months. Then they are usually removed slowly over several office visits. During this time, vision is usually very poor, and the stitches may cause discomfort. Even after all stitches are removed, vision may not return to normal because of warping or 'irregular astigmatism' that remains in the corneal graft.

Descemet's Stripping Endothelial Keratoplasty (DSEK)
In DSEK, the surgeon uses special instruments to enter the eye through a less than 1/4 inch incision in the front clear part of the eye (cornea). The back portion of the cornea (Descemet’s membrane) is then painlessly stripped away and replaced by a donor tissue. Although only a small piece of cornea is actually replaced, the graft will help keep the entire cornea clear.

DSEK has several advantages over Penetrating Keratoplasty.

• No stitches are placed in the cornea. In clinical studies, this has resulted in significantly less astigmatism after surgery and faster recovery of vision.

• In general, fewer follow-up exams are necessary because there are no corneal stitches to be removed. Ongoing studies are also examining whether corneal transplant rejection is less likely with DSEK than conventional transplants.