A 59 year-old male with Fuchs' endothelial dystrophy presented with visually limiting pseudophakic corneal edema in his right eye with a best-corrected visual acuity of 20/50. Cataract extraction had been performed two years previously in the right eye through a 3.2 mm limbal incision. An uncomplicated penetrating keratoplasty was performed, with an 8.25 mm donor cornea secured into an 8 mm recipient opening with 16 interrupted 10-0 nylon sutures. On the first postoperative day, the graft demonstrated diffuse 3+–4+ stromal edema and a nearly complete epithelial defect. The anterior chamber was deep, and no aqueous leakage was noted from either the wound or suture tracks. The epithelial defect resolved in the first postoperative week, although 1+–2+ stromal edema persisted. As the graft remained edematous 4 weeks later, the patient was diagnosed with PGF, and a repeat penetrating keratoplasty was performed 5 weeks after the primary graft. Three years later, the second graft remains clear, with a central pachymetry of 495 μm, and corrected visual acuity of 20/25+.
The host corneal button removed at the initial penetrating keratoplasty and the failed donor corneal button were formalin-fixed and analyzed with light microscopy after staining with hematoxylin and eosin, periodic acid-Schiff, and Masson trichrome stains. Histopathologic examination of the host corneal button revealed stromal edema, thickening and excrescences of Descemet's membrane, and a decreased number of endothelial cells, consistent with Fuchs' corneal dystrophy. Histopathologic examination of the failed corneal graft revealed a markedly thickened stroma and near complete absence of endothelial cells. Both sides of the excised donor corneal button were covered with epithelial cells, consistent with epithelial downgrowth. (Figure ) The corneal sections containing suture tracks were stained with the periodic acid Schiff stain to demonstrate Descemet's membrane. (Figure ) The suture tracks passed through the true epithelial layer, Bowman's layer, and extended into the stroma, confirming that the button had not been inverted when secured into the recipient opening. Additionally, serial sectioning of the host corneal button failed to demonstrate the presence of epithelial cells on the posterior corneal surface.
Figure 1 Histopathologic section of excised corneal button demonstrating a markedly thickened, edematous stroma and the presence of multilayered epithelial cells on the anterior and posterior surfaces (hematoxylin and eosin stain, original magnification × (more ...)
Figure 2 Histopathologic section of excised corneal button demonstrating anterior portion of suture track seen as focal tissue separation on superior side of corneal button. The identification of Descemet's membrane as a dark band on the inferior side of the corneal (more ...)
To investigate the possibility of HSV infection of the donor cornea, which has been associated with one-third of cases of PGF [4
], PCR analysis of the donor corneal button for HSV DNA was performed. Positive and negative controls confirmed adequate extraction of purified DNA from the failed donor corneal button, as well as the sensitivity and specificity of the HSV primers used. PCR analysis for HSV DNA was negative in the donor corneal button.
A complete review of the first donor's medical and eye bank records was performed. The tissue was obtained through the University of California, San Francisco tissue bank from a 56 year-old female donor who died from a myocardial infarction and cardiac tamponade. Routinely performed serologic screening tests and biomicroscopic examination of the donor button were unremarkable. The endothelial cell count was 2852 cells/mm2, and death to preservation was 12 hours, with a 51-hour preservation time in Optisol-GS.
The paired donor cornea was transplanted into another recipient several hours after this patient's original transplant. This cornea also appeared unremarkable on biomicroscopic examination, remained in Optisol-GS for 53 hours prior to transplantation, and had a cell count of 2841 cells/mm2. Five months later, after a similar 16 interrupted suture technique, the graft was clear and compact with central corneal pachymetry of 538 μm.