A Novel Microbubble Air Injection System for Controlled Graft Fixation in DMEK Surgery

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• Picked for Ophthalmology (paper of the day, 5 October 2026): Microbubble air system for DMEK graft fixation

Abstract

PURPOSE: To describe a novel, low-cost microbubble air injection system using a customized 3-French nasogastric tube for precise volume control and stable graft fixation during Descemet membrane endothelial keratoplasty (DMEK). DESIGN: Retrospective, single-surgeon observational study. METHODS: A total of 80 eyes of 80 patients who underwent DMEK surgery between 2021 and 2025 were included. All procedures were performed by a single corneal specialist with more than 15 years of corneal surgical experience and approximately 5 years of DMEK experience. The system consisted of a standard 27-gauge anterior-chamber cannula connected to a short segment of 3-French nasogastric tubing. Technical success was defined as generation and intracameral delivery of a microbubble sufficient to complete the intended graft-positioning/fixation maneuver without conversion to conventional syringe-based air injection. Device-related intraoperative complications, conversion, rebubbling, elevated intraocular pressure (IOP), primary graft failure, graft rejection, best-corrected visual acuity (BCVA), central corneal thickness (CCT), and postoperative endothelial cell density (ECD) were reviewed. RESULTS: Mean age was 65.8 ± 12.3 years. Fuchs endothelial corneal dystrophy accounted for 49 eyes (61.3%); 60 eyes (75.0%) underwent triple DMEK. Technical success was achieved in 80/80 eyes, with no conversion to a conventional syringe and no documented device-related intraoperative complication. Mean BCVA improved from 1.05 ± 0.61 to 0.43 ± 0.42 logMAR and mean CCT decreased from 630 ± 86.3 to 533.9 ± 55.8 µm. At 1 year, postoperative ECD was 1609 ± 563 cells/mm2; estimated ECL was 35.6 ± 22.5%. Rebubbling was performed in 27 eyes (33.8%); elevated IOP occurred in 7 (8.8%), primary graft failure in 3 (3.8%), and graft rejection in 2 (2.5%). CONCLUSION: The novel microbubble air injection system is a feasible modification for DMEK surgery. Ergonomic customization based on the surgeon's hand size is critical for achieving optimal mechanical control, leading to successful graft fixation across diverse endothelial pathologies.

Abstract as published, via PubMed.