Effectiveness of enoxaparin in preventing intraoperative fibrin formation during DMEK assessed in a before-and-after study

To demonstrate that enoxaparin in the irrigation saline solution can effectively prevent intraoperative fibrin formation (IFF) during Descemet membrane endothelial keratoplasty (DMEK) surgery without compromising graft viability, visual recovery, or intraoperative safety. A "before-and-after" study was conducted, comparing the rate of IFF in a prospective cohort of DMEK cases treated with enoxaparin to a retrospective cohort without treatment. Donor cornea characteristics, surgical data, rebubbling rate, final endothelial cell density (ECD), and best corrected visual acuity (BCVA) were analyzed. A total of 265 cases were analyzed. The incidence of IFF was 5.43% in the cohort without enoxaparin and zero in the enoxaparin-treated cohort. The risk ratio for enoxaparin use was 0 (confidence interval: 0), with a risk difference of -0.054 and a number needed to treat (NNT) of 18.42 cases to prevent one IFF event. No significant differences were found in baseline patients features or surgical aspects. The rebubbling rate was 16.98%, with no statistically significant difference between groups. No significant differences were observed in final ECD or BCVA between groups. In addition, no intraoperative complications or intraocular bleeding occurred with enoxaparin administration. Enoxaparin is a safe, effective, and cost-efficient prophylaxis for preventing IFF during DMEK surgery. It impedes the development of IFF, which may require a new and costly transplant when it occurs.