Identifying causes for poor visual outcome after DSEK/DSAEK following secondary DMEK in the same eye

To identify causes of reduced visual acuity after Descemet stripping (automated) endothelial keratoplasty (DSEK/DSAEK) and to determine whether such eyes can be successfully 'repaired' with a secondary Descemet membrane endothelial keratoplasty (DMEK).

Twelve eyes of 12 patients, who underwent secondary DMEK to manage poor visual outcome after initial DSEK/DSAEK, were evaluated with biomicroscopy, Pentacam imaging, and specular and confocal microscopy, before and at 1, 3 and 6 months after DMEK.

Four causes of reduced optical quality of the transplanted host cornea could be identified in DSEK/DSAEK: five eyes (42%) showed large host-Descemet remnants within the visual axis during surgery; six eyes (50%) irregular graft thickness; six eyes subtle 'stromal waves'; and nine eyes (75%) high reflectivity at the donor-to-host interface. After DMEK graft replacement, all corneas cleared and achieved a best corrected visual acuity of ≥20/25 (≥0.8), except for one with a partial Descemet graft detachment. Pachymetry values decreased from 670 (±112) μm before to 517 (±57) μm after secondary DMEK. Higher-order aberrations (Coma and Trefoil) at the posterior surface tended to be lower (p = 0.07) in DMEK grafts than in DSEK/DSAEK grafts.

Host-Descemet remnants at the donor-to-host interface, interface reflectivity, graft thickness irregularity and donor stromal contraction may contribute to poor visual outcome after DSEK/DSAEK, without causing permanent host corneal damage, as in most cases, complete visual recovery could be achieved by performing a secondary DMEK.