An outbreak of cataract with lens rupture and nuclear extrusion in wolf-fish (Anarhicas spp.)

Eight spotted (Anarhicas minor Olafsen) and five common wolf-fish (Anarhicas Lupus L), developed cataracts shortly after an episode of increased water temperature and decreased salinity 5 years prior to examination. On clinical examination, the cataracts were mostly bilateral and complete, and a majority of the lenses were lobulated. Inflammatory reaction was, apart from one eye with severe inflammation, limited to iris atrophy. Of the 14 eyes collected for pathomorphological examination, eight had lens rupture with extrusion of the nucleus to the posterior chamber, two showed partly dislocated nuclei with posterior protrusion and two lenses were morgagnian. A multilayered squamous epithelium with abundant desmosomes had developed on the surface of seven of the extruded nuclei. The main cause of the cataracts was considered to be the rapid decrease in water salinity, causing osmotic changes within the eyes with secondary swelling of lens fibers and rupture of the lens capsules.