Scheimpflug Densitometry After DMEK Versus DSAEK-Two-Year Outcomes.

Abstract

To compare the course of Scheimpflug corneal densitometry (CD) after Descemet membrane endothelial keratoplasty (DMEK) versus Descemet stripping automated endothelial keratoplasty (DSAEK). Fifty-four DMEK and 25 DSAEK cases without previous corneal surgery, complicated intraoperative or postoperative course, or vision-limiting ocular comorbidities were included. Pseudophakic eyes of age-matched subjects were recruited as controls (n = 20). Scheimpflug CD of the optically relevant zones (0-2 and 2-6 mm), best-corrected visual acuity (BCVA), endothelial cell density, and central corneal thickness were evaluated preoperatively and at 3, 6, 12, and 24 months postoperatively. CD of the optical zone decreased from 34.4 ± 9.4 grayscale units (GSU) before to 19.2 ± 2.7 GSU at 24 months after DMEK. Respectively, CD decreased from 34.0 ± 13.4 GSU before to 21.2 ± 2.5 GSU at 24 months after DSAEK. Mean central CD in group 3 was 18.1 ± 1.3 GSU. Compared with DSAEK, DMEK cases showed lower central CD at 3 and 6 months (P ≤ 0.012) but not at 12 and 24 months postoperatively. DSAEK showed higher CD values throughout the postoperative period compared with healthy controls (P < 0.001). DMEK showed higher CD compared with controls at 3, 6, and 12 but not at 24 months after surgery (P = 0.152). Postoperative BCVA was significantly better after DMEK for every examination time point. No difference in endothelial cell density was found between DMEK and DSAEK at any time point. DMEK showed lower CD and better BCVA compared with DSAEK in the first 6 postoperative months. Notably, although CD reached similar levels in the midterm after both DMEK and DSAEK, BCVA remained significantly better after DMEK.