This prospective, nonrandomized study found that Descemet's stripping automated endothelial keratoplasty (DSAEK) performed by experienced surgeons resulted in three-year graft survival and endothelial cell loss similar to penetrating keratoplasty (PK) performed with similar donor and recipient characteristics.
The authors compared outcomes from 173 patients who underwent DSAEK primarily for Fuchs' dystrophy or pseudophakic cornea edema with 1,101 patients from the Cornea Donor Study who underwent PK. The DSAEK procedures were performed by two experienced surgeons using the same donor criteria and similar recipient criteria as for the Cornea Donor Study PK procedures.
Three-year graft survival and endothelial cell loss was similar between the two techniques. The median three-year cell loss for DSAEK and PK was 46 percent and 51 percent, respectively, in Fuchs' dystrophy cases, and 59 percent and 61 percent, respectively (P = 0.70), in the non-Fuchs' cases. Use of a smaller DSAEK insertion incision was associated with significantly higher cell loss at three years (60 percent vs. 33 percent for 3.2- and 5.0-mm incisions, respectively), but not with a significant difference in graft survival. The three-year predicted probability of a rejection episode was 9 percent with DSAEK versus 20 percent with PK.
The principal causes of graft failure or regraft within three years after DSAEK and PK were immunologic graft rejection, endothelial decompensation in the absence of documented rejection, unsatisfactory visual or refractive outcome, and infection.
The authors note that compared with the PK cohort, the DSAEK cohort experienced more cell loss during the first year, which was probably related to surgical manipulation of and trauma to the graft. In subsequent years, however, the DSAEK cohort experienced a lower rate of cell loss than the PK cohort. They write that this is an interesting phenomenon that remains to be fully elucidated.
They conclude that longer-term follow-up of larger cohorts of DSAEK patients is needed to better assess the relative graft survival rates with these two procedures. The multicenter Cornea Preservation Time Study is expected to provide valuable insights regarding this.