Is DSAEK or DMEK better for failed penetrating keratoplasty (PKP)?
Reviewed by Bushra Thajudeen

This retrospective study involved 52 patients with failed penetrating keratoplasty. Twenty-eight eyes underwent Descemet membrane endothelial keratoplasty (DMEK) and 24 eyes underwent Descemet stripping automated endothelial keratoplasty (DSAEK). Data collection included demographic characteristics, number of previous corneal transplants, previous glaucoma surgeries, best-corrected visual acuity (BCVA), intraoperative complications, endothelial cell density (ECD), graft detachment and rebubble rate, rejection episodes, and graft failure. There was no difference in the number of corneal transplants before endothelial keratoplasty and the number of previous graft rejections between the two groups. Twelve eyes (43%) in the DMEK group and 12 eyes (50%) in the DSAEK group were regrafted because of failure. Graft failure in the DMEK group occurred more often during the early postoperative period (58%), whereas graft failure in the DSAEK group occurred more often in the late postoperative period (75%). Rebubbling was required in 12 of 28 eyes (43%) and three of 24 eyes (13%) in the DMEK and DSAEK groups, respectively (p=0.02). The BCVA six months after surgery was better in the DMEK group compared with the DSAEK group, measuring 0.50+/-0.46 LogMAR and 0.77+/-0.33 LogMAR, respectively (p=0.05). However, the degree of improvement of BCVA in the DSAEK group was more dominant than in the DMEK throughout the study period. The average ECD depletion six months after surgery was 52% in both groups. This study showed significantly higher rates of failure in both the DMEK and DSAEK groups in the setting of a failed PKP, with failure rates of 47% and 44%, respectively. Rebubbling rate of the DMEK post-PKP group in this study is comparable with previous publications (43%) and higher than the rate of primary DMEK detachments (12.5%). The rate of visual recovery and end point visual acuity was improved in the DMEK group, although preoperative baseline visual acuity was better in the DMEK cohort. Although DMEK and DSAEK both had increased rates of rejection compared with primary procedures, DMEK was consistent in its lower rejection rate than DSAEK. Graft detachments and subsequent primary failure were higher in the DMEK group, but overall failure rates equalised over time.

Comparison of Descemet stripping automated endothelial keratoplasty and Descemet membrane endothelial keratoplasty in the treatment of failed penetrating keratoplasty.
Einan-Lifshitz A, Mednick Z, Belkin A, et al.
CORNEA
2019;38(9):1077-82.