Purpose: To review the published literature on indications and outcomes of DSAEK/DSEK and DMEK for the treatment of failed penetrating keratoplasty.
Design: This is a systematic review and single-arm meta-analysis.
Methods: Literature searches were conducted in PubMed, Embase, Web of Science, and the Cochrane Database of Systematic Reviews. Prospective and retrospective studies reporting DSAEK/DSEK or DMEK after failed penetrating keratoplasty were included. Primary outcome measures are graft survival and detachment rates, as well as postoperative visual outcomes.
Results: A total of 25 studies with 970 patients/989 eyes were included, comprising 735 patients with 746 eyes which underwent DSAEK/DSEK surgery and 235 patients with 243 eyes which underwent DMEK surgery, all of them following a previously failed PK. There were no randomized controlled studies. In all of the DSAEK-PK studies, the graft failure rate was 18% (10%, 26%), the detachment rate was 15% (9%, 22%) and the rejection rate was 7% (3%, 12%) by the time of the last follow-up. And in all of the DMEK-PK studies, the graft failure rate was 14% (4%, 27%), the detachment rate was 42% (28%, 56%) and the rejection rate was 7% (2%, 16%). The mean visual acuity of the DSAEK-PK and DMEK-PK groups is 0.65 ± 0.18 and 0.43 ± 0.23 logMAR, respectively, at 6 months postoperatively.
Conclusions: Endothelial keratoplasty for treatment of failed penetrating keratoplasty led to improved vision and graft clarity in most recipients. Though graft survival rates and rejection rates were comparable between the two groups, the DMEK-PK group showed better visual outcomes with higher detachment rate.
Keywords: DMEK; DSAEK; Endothelial keratoplasty; Penetrating keratoplasty; Single-arm meta-analysis.