Corneal posterior crocodile shagreen and polymorphic amyloid degeneration

Globes were obtained post mortem from a 75-year-old patient who had both corneal posterior crocodile shagreen and polymorphic amyloid degeneration. The crocodile shagreen was typified by grayish, polygonal opacities with indistinct edges and separated by clear lines. The cloudy area involved the central two thirds of the corneas and included the posterior two thirds of the stroma, with increasing posterior density. The polymorphic amyloid degeneration was typical, demonstrating polymorphic punctate and filamentous deposits in the deeper corneal layers. The deposits appeared white in direct illumination and refractile in indirect illumination. Transmission electron microscopy revealed sawtoothlike configurations of the stromal collagen lamellae that corresponded to the central cloudy opacities seen clinically. The minute deposits were found to be amyloid by histochemical staining and electron microscopy.