ABSTRACT
Management of ocular neoplasia in captive fish is either by surgical removal of the tumor or entire eye, or humane euthanasia. Uveitis is inflammation of the uvea, which includes the iris, choroidal gland, ciliary body, and associated blood vessels of the eye. In freshwater fish, increasing the environmental salinity to 1-2 ppt (g/L) will reduce the osmotic gradient across the cornea and may help resolve corneal edema. Periodic monitoring for parasitic and bacterial diseases will help reduce the incidence of the etiologies. Numerous etiologies have been reported to cause unilateral or bilateral cataracts in both wild and captive fish, including nutritional, infectious, intralenticular parasites, trauma, excess ultraviolet light, changes in water temperature and hereditary factors. All fish species are probably susceptible to cataracts depending on the etiology. The histologic changes seen in cataracts of fish include hydropic swelling of the lens fibers, lysis of fibers, epithelial hyperplasia and intralenticular migration of surface epithelium.
