Clinical characteristics, risk factor analysis, and outcomes of graft rejection after Descemet membrane endothelial...

To report the clinical characteristics, risk factors, and outcomes of graft rejection after Descemet membrane endothelial keratoplasty (DMEK).

Of the total of 1026 eyes of 935 patients that underwent DMEK, 25 eyes of 25 patients had rejection. The risk factors in 25 eyes were compared with those of control eyes without rejection during the same study period. The control group consisted of 98 eyes of 98 patients, who underwent DMEK during the same period and had no episode of rejection at a minimum and regular follow-up period of 2 years from the time of surgery.

Overall, the incidence of rejection was 2.5%. The median age of patients was 53 (interquartile range, IQR, 45-62) years. In the control group, the median age was 65.5 (IQR 56.2-70.8) years. Most (88%) rejection episodes occurred within the first 2 years of surgery. Multivariate analysis showed younger age at surgery, male gender, rebubbling, cessation of topical steroids, and indication of DMEK (failed graft, corneal edema post-cataract surgery, and corneal edema due to inflammatory causes) as significant risk factors for graft rejection. No significant temporal correlation was observed with COVID-19 vaccination in the majority (92%). The mean endothelial cell loss following rejection was 72.5%. Kaplan-Meier survival plot showed the probability of graft survival was 90% at 1 year, 82% at 2 years, 80% at 3 years, 80% at 4 years, and 78% at 5-8 years.

Our study suggests that the risk of rejection is higher for indications such as failed previous graft, post-cataract surgery edema, and edema postinflammatory causes, when compared to Fuchs endothelial dystrophy. Topical steroids should be continued at least up to 2 years after surgery as this is the most common time frame of the rejection episode. The majority (68%) of the rejection episodes were reversible and resulted in a favorable outcome.