Clinicopathologic findings in failed descemet stripping automated endothelial keratoplasty

Abstract

Objective: To evaluate the clinical features of and histologic findings from failed Descemet stripping automated endothelial keratoplasty (DSAEK).

Methods: This retrospective observational case series evaluated 47 consecutive corneal specimens from 42 patients who underwent either penetrating keratoplasty or repeated DSAEK for failed DSAEK. Clinical information was obtained for the cases. Sections of the specimens were examined using light microscopy. Immunohistochemical staining was performed for cytokeratins AE1/AE3 and for the myogenic marker smooth-muscle actin when indicated. Transmission electron microscopic examination was performed in some cases.

Results: Graft survival ranged from 0.5 to 34 months. Histologic examination showed that 94% of the specimens (44 of 47) had endothelial cell loss. Residual host Descemet membrane (19%; 9 of 47), fibrocellular tissue (19%; 9 of 47), epithelial implantation (15%; 7 of 47), and fungal infection (4%; 2 of 47) were also identified. Immunohistochemical stains were positive for AE1/AE3 in the epithelial implantations and for smooth-muscle actin in cells in the fibrocellular proliferations.

Conclusions: The principal cause of failed DSAEK is endothelial cell loss. Residual host Descemet membrane, fibrocellular tissue at the edge of the lenticule, and epithelial implantation are common histologic findings. Fungal infection may occur in the setting of DSAEK.

Figure 1

Clinical appearance of failed Descemet stripping automated endothelial keratoplasties. A, Case 22. The graft is detached (arrows), and an air bubble is present in the anterior chamber. B, Case 28. The cornea is diffusely edematous in primary graft failure.

Figure 2

Endothelial cell loss. A, Case 8. The corneal stroma is thickened and edematous. A linear Descemet stripping automated endothelial keratoplasty scar is present (arrows), and there are 3 endothelial cells per high-power field (hematoxylin-eosin, original magnification ×100). B, Case 5. There are 0 endothelial cells per high-power field in the edematous graft (hematoxylin-eosin, original magnification ×100).

Figure 3

Retained Descemet membrane. A, Case 15. A piece of periodic acid–Schiff [PAS]–positive, partially folded Descemet membrane is sandwiched by the recipient and donor corneal stroma. The graft remains adherent to the central portion of the host stroma (PAS, original magnification ×25). B, Case 15. Electron microscopic examination shows retained Descemet membrane (arrows) present in the host-donor interface (original magnification ×1900). Inset shows that the interface contains electron-dense fibrillar material with scattered pigment granules (original magnification ×19 000). C, Case 9. Residual Descemet membrane is present peripherally, and there are 12 endothelial cells per high-power field in the cornea (PAS, original magnification ×25). D, Case 9. Descemet membrane has prominent posterior nodular excrescences (arrows), consistent with Fuchs endothelial dystrophy, indicating recipient Descemet membrane (PAS, original magnification ×100).

Figure 4

Fibrocellular tissue. Case 34. A, Proliferation of keratocytes with myofibroblastic differentiation is present on the peripheral stromal bed (arrows). The central portion of the stromal bed is smooth and hypocellular (thick arrows) (hematoxylin-eosin, original magnification ×25). Inset shows the proliferation of myofibroblasts at the periphery (hematoxylin-eosin, original magnification ×100). B, The fibrocellular tissue stains positive for the myogenic marker smooth-muscle actin (peroxidase antiperoxidase, original magnification ×100).

Figure 5

Epithelial implantation. A, Case 27. The lenticule is covered by multilayered epithelium on the anterior surface, along with the margin, and on the posterior surface (periodic acid–Schiff [PAS], original magnification ×25). Inset, These epithelial cells stain positive for cytokeratins AE1/AE3. The clefts are artifact (peroxidase antiperoxidase, original magnification ×100). B, Case 27. Transmission electron microscopic examination shows multilayered squamous epithelial cells with surface microvillae (arrows) present on the posterior surface of the Descemet membrane (original magnification ×2900). C, Case 11. A proliferation of nonkeratinized stratified squamous epithelium is present, forming a cyst between the recipient and the donor stroma (hematoxylin-eosin, original magnification ×25). D, Case 11. This cyst contains fluid with PAS-positive material in the lumen (original magnification ×100).

Figure 6

Fungal keratitis. A, Case 6. The graft is mostly detached. Residual Descemet membrane with posterior nodular excrescences is present at the host stromal surface. Periodic acid–Schiff (PAS)–positive fungal elements were observed at the host-donor interface (original magnification ×25). B, Case 6. Higher magnification shows yeast on the surface of the stromal bed (PAS, original magnification ×100). C, Case 12. The graft is detached. The corneal stroma is inflamed and ulcerated, with fungal hyphal elements and polymorphonuclear leukocytes (PMNs) in both recipient and donor sides (arrows). There are numerous PMNs present in the anterior chamber (thick arrows) (PAS, ×4). D, Case 12. Higher magnification shows fungal hyphae in the stroma (PAS, original magnification ×40).

Figure 7

Concomitant laser in situ keratomileusis (LASIK) scar. Case 4. A Descemet stripping automated endothelial keratoplasty lenticule (arrows) is partially detached from the posterior corneal surface, and a scar from previous LASIK surgery (thick arrows) is present anteriorly (hematoxylin-eosin, original magnification ×25).