Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK): Intra-Operative Effects on the Donor Corneal Endothelium

Abstract

Purpose:: To investigate the intra-operative impact of endothelial keratoplasty using the DSAEK technique on donor corneal endothelium in a laboratory model.

Methods:: A laboratory model of DSAEK was created using human corneoscleral donor tissue from the Georgia Eye Bank. The steps of DSAEK were studied independently to assess endothelial cell loss with each step of the procedure. The donor posterior corneal discs were placed in Optisol GS followed by staining with 1% alizarin red dye to analyze the endothelial buttons and measure overall endothelial cell loss. Each group was compared to a penetrating keratoplasty button control group.

Results:: The steps of DSAEK were divided into four groups. All groups were compared to a control group (trephinated corneal button in penetrating keratoplasty) which had a 5% endothelial cell loss. Group 1 included preparation of the donor button on the Moria artificial chamber and ALTK system. This group had an average endothelial cell loss of 17.1%. Group 2 added the steps of folding the prepared donor tissue with viscoelastic and grasping the tissue with non-compression Rossenwasser forceps. Average cell loss for this group was 16.4%. Group 3 included folding with insertion of the tissue using compression forceps and simulation of endothelial touch with chamber shallowing. This group demonstrated a 54.1% average endothelial cell loss. Group 4 included simulation of a 10-minute air bubble. This group had an average endothelial cell loss of 18.8%. The most significant amount of endothelial cell loss occurred with use of compression forceps along with the tissue insertion step.

Conclusions:: This study found a higher corneal endothelial cell loss with a simulated DSAEK technique compared to a control PK button group. The marked endothelial cell loss could account for higher primary graft failure rates in DSAEK compared to penetrating keratoplasty. Small incision insertion and compression forceps increase the amount of endothelial cell loss with the procedure. Surgeons may want to consider higher scrutiny of the endothelial morphology and cell count of donor tissue for DSAEK cases compared to penetrating keratoplasty cases to account for the increased endothelial loss from surgery.

Keywords: cornea: clinical science • cornea: endothelium • clinical laboratory testing