Avoiding Post-DMEK IOP Elevation: Insights from a Standardized Surgical Approach

Background: To assess the need of intraocular pressure (IOP)-lowering procedures following Descemet membrane endothelial keratoplasty (DMEK). Methods: We reviewed postoperative outcomes of consecutive patients, who underwent DMEK between May and December 2024 at the University Medical Center in Mainz, Germany. All surgeries included a surgical iridectomy at the 6 o’clock position, a tamponade with 10% sulfur hexafluoride (SF6) and IOP of about 15 mmHg at the end of surgery. Postoperative outcomes included IOP, per cent gas fill in the anterior chamber, and the need for IOP-lowering interventions, as determined by the on-call resident, at 3-, 24-, and 48-hours post-surgery. Complications, such as re-bubbling and re-keratoplasties, were also collected. Results: A total of 116 eyes from 98 patients (62 female, mean age 73.0±9.8 years) were analysed. DMEK was combined with cataract surgery in 41 eyes, and 4 eyes underwent phakic DMEK. The most common indication for DMEK was Fuchs' endothelial corneal dystrophy in 102 eyes. Postoperatively, all iridectomies remained patent, and no cases of pupillary block occurred. Mean IOP and gas fill at 3, 24, and 48 hours were 16.6±6.8 mmHg / 63±12%; 14.3±4.5 mmHg / 59±15%; and 13.0±3.5 mmHg / 55±15%, respectively. IOP-lowering procedures were performed in 11 eyes (9.5%) included venting (n=3), acetazolamide (n=7), and both (n=1). There was no difference between DMEK and triple-DMEK in terms of postoperative gas fill, IOP, or the need for IOP-lowering interventions. IOP-lowering interventions were more frequent in glaucoma vs. non-glaucoma patients. Conclusions: A standardized surgical approach incorporating a surgical iridectomy at the 6 o’clock position, 10% SF₆ tamponade and maintaining a mid-normal IOP at the end of surgery effectively prevented pupillary block and significant postoperative IOP elevations.