Abstract
Purpose :
To compare the re-bubbling rate as well as the functional results of Descemet Membrane Endothelial Keratoplasty (DMEK) using 20% sulfur hexafluoride (SF6) gas vs. air tamponade.
Methods :
88 consecutive eyes of 86 patients with Fuchs endothelial dystrophy (n=78), pseudophakic bullous keratopathy (n=8) or herpetic endotheliitis (n=2) from January 2017 until May 2018 were included. The DMEK operation was carried out by 4 experienced surgeons. As a tamponade, air was used in 37 eyes (group 1) and 20% SF6 in 51 eyes (group 2). The primary outcome measure was the re-bubbling rate and secondary outcome measures included pre- and 6 months postoperative best-corrected visual acuity (BCVA), mean intraocular pressure (IOP) of multiple measurements on the day of surgery, central corneal thickness (CCT) and postoperative endothelial cell density after 6 months.
Results :
The mean age of patients was 71.7 ± 7.8 (52 - 86) vs. 73.8 ± 8.1 (54 - 91) years. At least one re-bubbling was required in 21 patients in group 1 (57%) vs. 11 patients in group 2 (21%) (p = 0.01). The mean BCVA was preoperatively 0.26 ± 0.1 (0.05 - 0.6) vs. 0.33 ± 0.1 (0.1-0.5) (p = 0.07) and postoperatively 0.63 ± 0.1 (0.4-1.0) vs. 0.67 ± 0.1 (0.2-1.0) (p = 0.33) in group 1 and 2, respectively. The mean postoperative IOP on the day of surgery in group 1 and 2 was 13.2 ± 3.3 (8 - 19) vs. 13.0 ± 3.3 (8 -19) mmHg, respectively (p = 0.76). In group 1 vs. 2, mean CCT was preoperatively 654.3 ± 90.7 (532 - 954) vs. 660.2 ± 82.3 (510 - 856) μm (p = 0.78) and postoperatively 513.3 ± 40.2 (443 - 597) vs. 517.1 ± 45.2 (462 - 608) μm, respectively (p = 0.72). Mean endothelial cell density at 6 months did not differ significantly between group 1 (1461 ± 258 (833 - 1795) /mm2) vs. group 2 (1577 ± 361 (843 -1982) /mm2) (p=0.11).
Conclusions :
The incidence of graft detachment and thus the need for re-bubbling seems to be significantly lower after primary tamponade with 20% SF6 gas compared to air without increased risk of short-term IOP rise or postoperative endothelial cell loss.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.