Outcomes Of Descemet Membrane Endothelial Keratoplasty For Fuchs Endothelial Corneal Dystrophy Depending On The Presence Of Clinical Versus Subclinical Corneal Edema

To compare the surgical outcomes after Descemet Membrane Endothelial Keratoplasty (DMEK) in Fuchs endothelial corneal dystrophy (FECD) patients with subclinical corneal edema and clinical corneal edema.

Prospective, observational, single-center cohort study in a tertiary hospital in Germany.

A total of 106 pseudophakic eyes of 85 patients with FECD were divided into two groups depending on the presence of preoperative subclinical and clinical corneal edema. Subclinical corneal edema was diagnosed if more than one of the following criteria was present in Scheimpflug tomography: loss of regular isopachs, displacement of the thinnest point, and focal posterior depression. Clinical edema was diagnosed by slit-lamp biomicroscopy. The primary outcome was the corrected distance visual acuity (CDVA) four months after DMEK. Secondary outcomes were central corneal thickness (CCT), thinnest corneal thickness (TCT), and total corneal density (TCD) in Scheimpflug tomography, as well as endothelial cell loss (ECL) and the re-bubbling rate.

The postoperative CDVA was significantly better in the group with subclinical edema compared to the group with clinical edema (p = 0.026). Four months after DMEK the TCD was higher in the group with preoperative clinical edema (31.7 ± 8.3 GSU) compared to the group with subclinical edema (p = 0.005; 27.8 ± 6.1 GSU). The postoperative CCT, TCT, ECL, and re-bubbling rates did not differ significantly between both groups (all p > 0.05).

DMEK for FECD yielded better visual acuity when performed in the early stage of FECD compared to a later stage with clinical edema. This may be attributable to a persistent corneal fibrosis after DMEK in eyes with preoperative clinically evident corneal edema, as suggested by higher postoperative corneal density in eyes with clinical edema. Consequently, our findings advocate for the consideration of earlier DMEK in FECD patients to achieve better surgical outcomes.