Comparison of 5% Sulfur Hexafluoride Versus 100% Air Tamponade in Descemet Membrane Endothelial Keratoplasty

PURPOSE: To compare the rebubbling rate and clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) with 5% sulfur hexafluoride (SF6) gas versus 100% air as a tamponade for graft attachment. METHODS: Retrospective, comparative, interventional case series including 368 consecutive pseudophakic eyes with Fuchs endothelial dystrophy or pseudophakic bullous keratopathy that underwent DMEK in a tertiary referral center between October 2010 and August 2015 using either air (group 1, 191 eyes) or 5% SF6 (group 2, 177 eyes) as a tamponade. The rebubbling rate, complications, best-corrected distance visual acuity (BCVA), manifest refraction, and endothelial cell density were analyzed before and at 1 week, 1, 3, 6, 12, 24, and 36 months after surgery. RESULTS: The rebubbling rate was 20.4% (39/191, group 1) versus 6.8% (12/177, group 2; P < 0.001). Complications included cystoid macular edema (n = 5, group 1, and n = 10, group 2; P = 0.14) and 1 case of presumed allograft rejection (n = 1, group 2). The follow-up period was 12 ± 8 months for group 1 and 6 ± 4 months for group 2. BCVA (logarithm of the minimum angle of resolution) had improved after 12 months from 1.43 ± 0.63 to 0.18 ± 0.26 (group 1, P < 0.001) and from 1.8 ± 0.63 to 0.18 ± 0.17 (group 2, P < 0.001). The percentage of eyes with BCVA ≥0.2 logarithm of the minimum angle of resolution at 12 months was 70.9% (90/127, group 1) and 78.4% (40/51, group 2; P = 0.3). Endothelial cell loss at 12 months after DMEK was 44 ± 18% (group 1) versus 33 ± 15% (group 2, P = 0.07). CONCLUSIONS: The use of a tamponade with 5% SF6 yielded a significantly lower incidence of graft detachment requiring surgical reintervention with no detrimental effect on graft endothelial cells. Thus, routine use of 5% SF6 for a graft tamponade in DMEK is recommended.