Corneal Opacity Associated with Eye Disease in Hatchery-Reared Lake Trout ∗ †

Summary

Lake trout raised in a hatchery environment develop corneal lesions and opacities with a gross configuration similar to that observed in human keratoconus. Ultrastructural examination of this lesion shows that in the early stages of disease, the endothelial cells become distorted in shape and vacuolization occurs within the cytoplasm. As the corneal changes progress, the kerato-cytes enlarge and develop extensive endoplasmic reticulum, increasing the stromal thickness and displacing the parallel alignment of the collagen lamellae. There are no observable changes in epithelial thickness or morphology.