Corneal dystrophies are diseases of the cornea that occur in both eyes, are not related to inflammation, and are inherited. In most cases a dystrophy appears as a gray-white crystalline or metallic opacity in the substance of the cornea. These opacities are usually oval or round. They often become progressively larger, but in some cases remain the same size. Rapid progression usually leads to blindness. Slow progression may or may not lead to blindness.
Corneal dystrophy is a genetic disorder that affects many breeds, including the Collie, Siberian Husky, Cavalier King Charles Spaniel, Beagle, Airedale Terrier, Cocker Spaniel, Alaskan Malamute, Bearded Collie, Bichon Frise, German Shepherd Dog, Lhasa Apso, Shetland Sheepdog, Chihuahua, Miniature Pinscher, Weimaraner, Pointer, and Samoyed. The age of onset, rate of progression, appearance, and location of the opacities and mode of inheritance vary with the breed and the individual dog. In some breeds, such as the Siberian Husky, the disease is evident as early as 4 months of age; in others, such as the Chihuahua, it appears as late as 13 years. In the Airedale the problem is sex linked, with males affected and generally showing signs by 1 year of age.
Some cases of corneal dystrophy are complicated by the development of a corneal ulcer.
Treatment: There is no effective treatment. A corneal dystrophy that threatens eyesight can be removed surgically. This may temporarily improve vision, but the opacity will re-form.
Prevention: Corneal dystrophies can be identified by veterinary eye examination. Affected individuals should not be used for breeding. The mode of inheritance has been determined for some breeds. This may make it possible to project which dogs in the pedigree are carriers. For more information, see Retinal Diseases.