Graft survival and endothelial outcomes in the new era of endothelial keratoplasty

Abstract

Corneal endothelial cells do not proliferative in vivo sufficiently to enable endothelial regeneration, and thus diseases of the corneal endothelium, which cause poor vision and discomfort, require treatment by transplantation of cadaveric donor corneal endothelial cells. The two major goals of any corneal transplant procedure are to restore vision and to promote longevity of the donor cornea by maintaining a healthy donor endothelial cell density. Over the last decade, the surgical treatment for endothelial disease has rapidly evolved toward endothelial keratoplasty, or selective tissue transplantation, and away from full-thickness penetrating keratoplasty (PK). While endothelial keratoplasty offers distinct advantages over PK in terms of visual outcomes and a smaller incision, the new surgical manipulations of the fragile donor tissue cause significant donor endothelial cell trauma. As a result, donor endothelial cell loss is much higher during the first month after Descemet stripping endothelial keratoplasty (DSEK) compared to after PK, and the primary (or more appropriately, iatrogenic) graft failure rate of 5% remains unacceptably high. Nevertheless, the rate of endothelial cell loss rapidly decreases beyond 6 months after DSEK, and thus endothelial cell loss at 5 years after DSEK appears to be lower than that at 5 years after PK. In the absence of primary (iatrogenic) graft failure, graft survival through 5 years after DSEK is similar to that after PK. Given the promising longer-term endothelial outcomes of DSEK, the quest for optimizing the visual outcomes has spurred interest in Descemet membrane endothelial keratoplasty (DMEK). While early results after DMEK suggest better visual outcomes than after DSEK, the technique needs to be simplified, and longer-term outcomes must show an advantage over DSEK with respect to vision, endothelial cell loss, and graft survival. DMEK also has a high rate of primary (iatrogenic) graft failure, and additional donor tissue wastage occurs when preparation of DMEK grafts is unsuccessful. This review discusses endothelial keratoplasty techniques and the associated endothelial outcomes.

Endothelial cell loss and complication rates with combined Descemets stripping endothelial keratoplasty and cataract surgery in a UK centre

“…[12][13][14] With endothelial keratoplasty continually evolving, it will be pertinent to establish the role of combined cataract surgery in these newer techniques. 14,15 In conclusion, mean ECL and complication rates were comparable at 6, 12 and 24 months in routine cases undergoing concurrent DSEK with cataract surgery and those undergoing DSEK. To our knowledge, this is the largest UK data series reporting ECCs.…”

Immune Cells on the Corneal Endothelium of an Allogeneic Corneal Transplantation Rabbit Model

“…6,[15][16][17] Corneal transplantation performed as a DSEK procedure in the rabbit gave a successful graft in all cases, with a transparent cornea and no serious complications such as graft rejection, graft failure, or graft dislocation. Representative slit-lamp microscopic images showed attachment of the graft to the back side of cornea, and corneal transparency was maintained in the rabbit model 2 weeks after surgery (Fig.…”

“…Corneal transplantation has been accepted as a successful procedure, but several large cohort studies have now shown that graft survival after 10 years following penetrating keratoplasty (PK) is only approximately 50%, [3][4][5] although this varies widely depending on the indications and the specific studies. 6,7 Endothelial dysfunction also accounts for 50% of the total graft failures, suggesting that corneal endothelial damage is the leading cause of graft failure. 5,7 Endothelial graft failure can be divided into three types: primary graft failure (mainly iatrogenic), immunologic rejection, and late endothelial failure.…”

“…5,7 Endothelial graft failure can be divided into three types: primary graft failure (mainly iatrogenic), immunologic rejection, and late endothelial failure. 6 Graft rejection is clinically recognized by features that include the presence of endothelial rejection line, keratic precipitates, corneal edema, and conjunctival injection caused by immunologic responses against donor cells. [8][9][10] One multicenter study revealed that 92 of 1090 patients (8.4%) experienced graft failure within 5 years of follow-up due to rejection after PK.…”

Effect of a p38 Mitogen-Activated Protein Kinase Inhibitor on Corneal Endothelial Cell Proliferation

“…8 However, worldwide cornea donor shortages, chronic graft failure due to long-term continuous cell loss after transplantation, and difficulties in surgical procedures for endothelial keratoplasties are still problems that limit the effectiveness of these procedures in the clinical setting. 8,9 This has prompted efforts to develop tissue-engineering therapies that can overcome the problems associated with conventional corneal transplantation.…”