Scheimpflug Corneal Densitometry Patterns at the Graft–Host Interface in DMEK and DSAEK: A 12-Month Longitudinal Comparative Study

Background: To compare corneal densitometry (CD) patterns at the graft–host interface between Descemet Membrane Endothelial Keratoplasty (DMEK) and Descemet Stripping Automated Endothelial Keratoplasty (DSAEK). Corneal densitometry is a quantitative assessment that objectively evaluates corneal clarity and optical quality by measuring the light backscatter from the cornea. Methods: Fifty-one eyes that received DMEK or DSAEK surgery for corneal endothelium dysfunction were evaluated. The primary endpoint included CD patterns at the graft–host interface, which were assessed by the Pentacam HR device at the center point of the corneal horizontal meridian (CD_central), and at six points on the central circumference of the cornea (with a total diameter of 4 mm) (CD_{I,II,III,IV,V,VI}). Secondary endpoints included the best-corrected distance visual acuity (BCDVA), central corneal thickness (CCT), and graft thickness (GT). All of the evaluations were performed at follow-up appointments one, three, six and twelve months after the procedure. Results: DMEK showed a significant overall CD reduction of −7.9 ± 8.5 grayscale unit (GSU) compared to DSAEK (p < 0.001). In addition, the DMEK group showed significantly lower CD_{Central,I,II,III,IV,V,VI} values at follow-up appointments one, three, six and twelve months after the procedure compared to the DSAEK group (p < 0.001). BCDVA, CCT and GT were in favor of the DMEK group with a mean value of 0.39 ± 0.35 LogMar, 552.2 ± 71.1 µm and 11.03 ± 1.4 µm, respectively (p < 0.001). Conclusions: CD patterns at the graft–host interface seem to be different depending on the endothelial keratoplasty procedure. This provides specific insight into CD changes in this critical region of surgery, which may provide a better understanding of the postoperative evolution of these patients.