Descemet membrane endothelial keratoplasty with a stromal rim in the treatment of posterior polymorphous corneal dystrophy.

A 20-year-old patient, diagnosed with posterior polymorphous corneal dystrophy, developed corneal edema for which he underwent Descemet membrane endothelial keratoplasty with a stromal rim (DMEK-S) in the right eye. No intra- or postoperative complications were noted. At the last follow-up 2 years and 9 months after the procedure, the best corrected visual acuity was 1.0 and endothelial cell density declined from 3533 cells/mm2 to 1012 cells/mm2. Despite the endothelial cell loss, DMEK-S appears to be a good alternative to other surgical techniques for the treatment of corneal endotheliopathies, and it may be of benefit to young patients.

A Comparison of Posterior Lamellar Keratoplasty Modalities: DLEK vs. DSEK

PURPOSE: To compare clinical outcomes after deep lamellar endothelial keratoplasty (DLEK) with Descemet stripping endothelial keratoplasty (DSEK) performed as initial cases by a single surgeon. METHODS: Sixteen patients with corneal endothelial were enrolled. Eight patients (8 eyes) underwent DLEK and 8 patients (8 eyes) DSEK. We measured uncorrected visual acuity, best corrected visual acuity (BCVA), manifest refraction, corneal endothelial count, interface opacity via Schiempflug imaging, and contrast sensitivity, as well as tracked postoperative complications over the first postoperative year. RESULTS: Primary graft failure occurred in two DLEK cases and one DSEK case, all of which were excluded for further analysis. The average 12-month postoperative BCVA was 20/70 in the DLEK group and 20/50 in the DSEK group, with the difference not statistically significant. No significant differences were identified between the 2 groups in terms of mean spherical equivalent and refractive astigmatism, although individuals in the DSEK group tended toward hyperopia. The average endothelial cell count at postoperative month 12 was 1849+/-494 in the DLEK group and 1643+/-417 cells/mm2 in the DSEK group, representing cell losses of 26.2% and 31.9%, respectively. No significant differences in endothelial cell count or endothelial cell loss were observed between groups. Early postoperative donor disc dislocation occurred in two eyes after DLEK and one eye after DSEK. Interface opacities and contrast sensitivities were similarly not significantly different between groups. CONCLUSIONS: No significant differences in any assessed clinical outcome were observed between individuals undergoing DLEK and DSEK, when performed as initial cases by a single surgeon.

Graft Adhesion and Recovery of Corneal Function after Posterior Lamellar Keratoplasty

PURPOSE: Posterior lamella keratoplasty has been described as a new procedure to treat corneal conditions involving endothelial dysfunction by selective transplantation of only the posterior corneal tissue composed of the endothelium, Descemet membrane, and posterior stroma. This study has been conducted to evaluate the recovery of endothelial function and adhesion mechanism of transplanted posterior corneal tissue to the donor stroma after posterior lamella keratoplasty. METHODS: Dog corneal endothelium and posterior stroma were transplanted to recipient dog cornea stripped of endothelium and posterior stroma. The recovery of endothelial function and corneal thickness were measured by specular microscopy; pachymetry and slit lamp examination were done immediately after posterior lamella keratoplasty and at 1, 2, 4, 8 weeks post-operative. Eight weeks after operation, enucleation was performed and the histopathologic changes in the transplanted area of enucleated eyes were examined by light microscopy, fluorescent microscopy, and electron microscopy. RESULTS: Corneal thickness, endothelial function, and corneal transparency were recovered by the end of experiment. The newly produced collagen fibrils were absent at the corneal posterior flap and anterior stromal bed interface. The collagen fibrils adjacent to the flap interface were irregularly arranged and morphologically transformed in some cases (2 of 8 cases) and were linearly arranged in a parallel manner in others (6 of 8 cases). CONCLUSIONS: It can be suggested that the stability of transplanted posterior corneal flap is maintained by incomplete wound healing and recovery of corneal endothelial function.