Scheimpflug Densitometry After DMEK Versus DSAEK—Two-Year Outcomes

Purpose: To compare the course of Scheimpflug corneal densitometry (CD) after Descemet membrane endothelial keratoplasty (DMEK) versus Descemet stripping automated endothelial keratoplasty (DSAEK). Methods: 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. Results: 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. Conclusions: 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.