MAR 25, 2010
Francis Price, Jr., MD, and colleagues report one-year results from their prospective, nonrandomized clinical trial including 73 patients undergoing Descemet's stripping automated endothelial keratoplasty (DSAEK) and compared them with 410 patients undergoing penetrating keratoplasty (PKP) from the Specular Microscopy Ancillary Study (SMAS) of the Cornea Donor Study.
The inclusion and exclusion criteria applied were similar to those used in the SMAS with exception of age. On average, donor corneas had 91cells/mm2 more endothelial cells and were 3 years younger in the DSAEK group compared to SMAS. Fuchs' dystrophy was the more common indication for surgery in the DSAEK group compared to the SMAS group (85 percent vs. 64 percent). Among the SMAS group, the rate of cell loss was less in Fuchs' dystrophy compared to bullous keratopathy.
While the one-year graft rate was comparable, endothelial cell loss in the DSAEK group at six months (34 percent) and 12 months (38 percent) was significantly greater than the PKP group at six months (11 percent) and 12 months (20 percent), a finding the researchers attribute primarily to greater surgical manipulation and trauma to the graft.
Interestingly, initial diagnosis (Fuchs' vs bullous keratopathy) demonstrated similar cell loss rates in the DSAEK group. Unfortunately visual and refractive results were not included in the studies.
Long-term follow-up will be significant. This study showed that cell loss in DSAEK patients plateaued more quickly than in those who underwent PKP. It will be interesting to see if the rate of cell loss over time slows after the initial cell loss at the time of DSAEK surgery. In addition, the lower rate of increased intraocular pressure in the DSAEK group may become significant in the long-term follow-up as this is one of the most important factors with graft survival.