Corneal Remodeling After DMEK in Fuchs Endothelial Dystrophy Patients: Quantitative and Qualitative Changes

Background/Objectives: Fuchs endothelial corneal dystrophy (FECD) affects not only the corneal endothelium and Descemet membrane, but also the corneal thickness, shape, and optical quality. This study aimed to evaluate the quantitative and qualitative corneal changes after a Descemet membrane endothelial keratoplasty (DMEK) in patients with FECD and to compare the postoperative remodeling between eyes with subclinical corneal edema (F-SCE) and those with clinically evident corneal edema (F-CE). Methods: This retrospective observational study included 48 eyes of 40 patients with FECD who underwent DMEK between April 2023 and October 2025. The following parameters were assessed preoperatively and at 6 months postoperatively: central corneal thickness (CCT), mean pupillary power (MPP), anterior and posterior corneal astigmatism, total corneal higher-order aberrations (HOAs), anterior and posterior optical path difference (OPD), point spread function (PSF), anterior and posterior corneal surface regularity (RMS/A), and Gullstrand anterior/posterior (A/P) and posterior/anterior (P/A) ratios. The corneal data was obtained using a CSO MS-39 (Costruzione Strumenti Oftalmici, Firenze, Italy). Results: In the F-SCE subgroup, significant postoperative improvement was observed in the CCT (Δ = -84.6 ± 48.1 µm, p < 0.001), MPP (Δ = -1.010 ± 2.183, p < 0.001), posterior corneal regularity (posterior RMS/A) (Δ = -0.117 ± 0.229, p = 0.004), and both Gullstrand ratios (A/P: Δ = +0.111 ± 0.089, p < 0.001; P/A: Δ = -0.078 ± 0.064, p < 0.001). No significant change was detected in the anterior corneal regularity, anterior or posterior astigmatic metrics, total corneal higher-order aberrations, or PSF. In the F-CE subgroup, the postoperative response was greater, with significant improvement in the BCVA, CCT, thinnest corneal point, MPP, anterior and posterior corneal astigmatism, cylinder, total corneal HOAs, anterior and posterior corneal HOAs, PSF, anterior and posterior corneal regularity, and both Gullstrand ratios. Compared with the F-SCE eyes, the F-CE eyes showed significantly greater postoperative change in most structural and optical parameters, although most 6-month postoperative values were no longer significantly different between groups. Conclusions: DMEK induced significant corneal remodeling in both subclinical and clinically evident FECD. The eyes with subclinical edema demonstrated meaningful recovery in visual acuity, pachymetry, and posterior corneal regularity, supporting the presence of functional corneal impairment before a clinically visible edema. The eyes with clinically evident edema showed a broader and greater postoperative response, while the final postoperative values largely converged between groups.