Secondary DMEK following failed primary DMEK

Abstract

Purpose: To report the outcomes of secondary Descemet Membrane Endothelial Keratoplasty (DMEK) performed for failed primary DMEK.

Methods: The medical records of all patients undergoing secondary DMEK due to failure of primary DMEK were reviewed. Reasons for failure were sought and best-corrected visual acuity (BCVA), endothelial cell density (ECD) and complications of secondary DMEK were evaluated.

Results: A total of 10 cases undergoing secondary DMEK following failed primary DMEK were identified. Presumed reasons for failure included donor ECD ≤ 2300 cells/mm² (n = 4), difficulty during graft preparation (n = 2), graft detachment (n = 2), acute angle closure due to retroiridal air dislocation (n = 1), inverse graft positioning (n = 1) and phacoemulsification (n = 1). Eyes with low visual potential were not excluded from the study group. We should note that one patient (case no7) had both low ECD and graft detachment as reasons for failure and as a result he is counted twice. Median BCVA (decimal fraction) increased from 0.1 (range, 0.01; 0.3) to 0.5 (0.05; 1.0) at one month and remained stable thereafter. A BCVA of 0.5 or higher was achieved in 7 cases at the final follow-up. Mean ECD fell from 2628 ± 284 cells/mm² to 1391 ± 252cells/mm² at 6 months (47% reduction) and 959 ± 225cells/mm² at 24 months (64% reduction) (P ≤ 0.028). Complications included the incomplete removal of the primary graft and mild iris bleeding, decompensation of a preexisting primary open-angle glaucoma and retroiridal air dislocation.

Conclusions: Apart from low donor ECD, surgical challenges, i.e., difficulty with graft preparation, inverse graft positioning, and retroiridal air dislocation, were main reasons for failure of primary DMEK. Secondary DMEK showed a good safety profile and reasonable visual outcomes.

Keywords: DMEK; DSAEK; Endothelial cell density; Graft survival; Penetrating keratoplasty.