The posterior corneal surface in Fuchs' dystrophy. Scanning electron microscope study.

This study comprises 12 corneal buttons removed at the time of keratoplasty from patients with bullous keratopathy due to Fuchs' dystrophy. All except one were aphakic. Three had vitreous contact to the endothelium. One patient had several intraocular procedures. Specimens were processed for scanning electron microscopy and dried in a freeze-drying or critical-point machine. Portions of these specimens were processed for transmission electron microscopy or paraffin sectioning. Specimens can be separated in three groups based on our findings: (A) corneas with abnormal or absent endothelium; posterior surface with many fibroblast-like cells; long filaments over Descemet's membrane; and few and small warts. (B) Endothelial cells were present for the most part. Cells were of abnormal size and shape with fibroblastic cells present over or between them; no warts or filament were seen. (C) Absent or abnormal endothelial cells, with no fibroblastic cells; Descemet's layer was covered with a profuse number of warts of oval or rounded shape and of different sizes. It is believed that the fibrils seen in specimens of Group A with vitreous contact may correspond to vitreous strands. The fibroblastic cells present in many aphakic corneas could have originated by metaplasia of endothelial cells or from macrophages of uveal origin. Vitreous contact may have occurred before or after these changes in Descemet's membrane.