Purpose
To investigate the in vivo corneal changes in patients with bullous keratopathy who underwent Descemet membrane endothelial keratoplasty (DMEK) with the use of in vivo laser confocal microscopy.
Methods
Five eyes of four patients (three men, one women; mean age, 61.3±9.6 years [mean ± standard deviation]) with bullous keratopathy who had undergone successful DMEK were enrolled in this study. In vivo laser confocal microscopy was performed before and one, three, and six months after DMEK. Selected confocal images of corneal layers were evaluated qualitatively and quantitatively for the degree of haze and the density of deposits. Subepithelial haze, donor-recipient interface haze, donor-recipient interface particles, and host stromal needle-shaped materials were graded on a scale of 4 categories (grade 0; none, grade 1; mild, grade 2; moderate, grade 3; severe) at each time point. Time trends of the outcomes were graphically displayed and evaluated with Mantel-Haenszel trend test.
Results
Preoperatively, the following were observed in all patients: slight corneal epithelial edema, moderate subepithelial haze, keratocytes in a honeycomb pattern, and tiny needle-shaped materials in the stroma. After DMEK, moderate subepithelial haze persisted during the follow-up period. Needle-shaped materials had a tendency to decrease after DMEK. Most notably, donor-recipient interface haze and donor-recipient interface particles were barely noticeable after DMEK as early as one month postoperatively.
Conclusions
In vivo laser confocal microscopy can identify subclinical corneal abnormalities after DMEK such as subepithelial haze, host stromal needle-shaped materials, and minimum donor-recipient interface haze/particles. These abnormalities seemed subtle compared to Descemet stripping automated endothelial keratoplasty; this may explain the superior postoperative visual acuity after DMEK. Further studies with this technology in a large number of patients and long-term follow up are needed to fully understand the long-term corneal changes after DMEK.
Keywords: 481 cornea: endothelium