Descemet Membrane Endothelial Keratoplasty (DMEK)

Descemet membrane endothelial keratoplasty (DMEK) is the standard surgical treatment for corneal endothelial disorders. A postoperative pupillary block may occur despite routine preoperative laser iridotomy or intraoperative surgical iridectomy. Insufficient size or incomplete patency of the iridotomy/iridectomy (IT) may contribute to this complication, while excessively large openings may be associated with postoperative dysphotopsia. This prospective observational study investigates the association between IT size measured by anterior segment optical coherence tomography (AS-OCT) and the occurrence of postoperative pupillary block and dysphotopsia after DMEK.

The goal of this clinical trial is to learn if a longer period of lying on the back after corneal transplant surgery (Descemet Membrane Endothelial Keratoplasty, DMEK) helps the transplant stick better in the eye. It will also learn about side effects, such as back pain. The main questions it aims to answer are: * Does lying on the back for 5 days reduce the size of transplant detachment compared to lying on the back for only 1 day? * Do participants who lie on their back longer need fewer additional procedures (rebubbling)? * What symptoms or problems do participants experience with short vs. long back positioning? Researchers will compare two groups: * 1 day of back positioning * 5 days of back positioning Participants will: * Be randomly assigned to one of the two positioning groups * Wear a movement sensor that records head position * Have their eyes checked regularly with vision tests and imaging (AS-OCT) * Answer questions about their vision and comfort * Keep a diary of any positioning-related complaints, such as back pain

The DMEC trial is a randomized clinical two-arm trial comparing inflammation and cystoid macular edema for the medication regimens postoperative topical NSAIDs and steroids to only postoperative topical steroids in patients undergoing corneal endothelial transplantations (DSAEK or DMEK).