Modified “Needle-In-Needle” Safety-Net Suture for DMEK in Eyes With Large Iris Defects and Prior Vitrectomy

Purpose: To describe a modified “needle-in-needle” safety-net suture technique that enhances graft stability and prevents posterior donor dislocation during Descemet membrane endothelial keratoplasty (DMEK) in eyes with a functionally unicameral anterior chamber environment characterized by large iris defects after open-globe injury. Methods: This retrospective case series included 3 eyes of 3 patients who underwent DMEK using the modified safety-net suture. A 10-0 polypropylene needle was docked into a 30-gauge needle introduced from the opposite side, allowing precise suture passage from limbus to limbus under direct visualization. A 3 × 3 or 3 × 5 mesh temporarily supported the graft during unfolding and was removed after air tamponade. Best-corrected visual acuity (BCVA), central corneal thickness (CCT), endothelial cell density (ECD), and complications were evaluated. Results: All patients (3 men; mean age 71.0 ± 6.2 years) had endothelial decompensation secondary to open-globe injury with large iris defects. No intraoperative posterior dislocation occurred. One eye (33.3%) required 2 rebubbling procedures for peripheral detachment, after which complete graft attachment was achieved. Mean BCVA improved from logMAR 1.23 ± 0.21 to 0.54 ± 0.15, CCT decreased from 829 ± 141 μm to 574 ± 18 μm, and ECD was 1137 ± 146 cells/mm 2 at 2 years. Conclusions: The modified needle-in-needle safety-net technique improves visualization, precision, and safety during DMEK in complex anterior segment cases. Despite substantial endothelial cell loss reflecting extreme case complexity, this approach effectively prevents posterior dislocation and represents a viable salvage strategy that expands DMEK applicability to anatomically challenging eyes with functionally unicameral anterior chambers.