Corneal dystrophies are a group of diseases that affect the

cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical ...

in dogs.

Treatment

Corneal dystrophy in dogs usually does not cause any problems and treatment is not required. Suboptimal vision caused by corneal dystrophy usually requires surgical intervention in the form of corneal transplantation. Penetrating keratoplasty is commonly performed for extensive corneal dystrophy.

Corneal endothelial dystrophy

Corneal endothelial dystrophy is an age-related change that affects the inner layer of the corneal, the

endothelium The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vesse ...

. Leakage of fluid into the cornea causes edema, causing a bluish appearance. This will eventually involve the whole cornea. Bullous keratopathy ( blisters in the cornea) may also form, leading to nonhealing and recurrent corneal ulceration.

Hyperosmotic In chemical biology, tonicity is a measure of the effective osmotic pressure gradient; the water potential of two solutions separated by a partially-permeable cell membrane. Tonicity depends on the relative concentration of selective membrane- ...

agents are sometimes used topically for treatment, but success with these medications is inconsistent and can cause irritation. Bad cases may require a corneal transplant or thermokeratoplasty, which is a grid of superficial burns to the cornea that causes anterior stromal fibers to contract and prevent fluid uptake by the stroma. The most commonly affected breeds are the Boston Terrier, Chihuahua, and Dachshund. The age of onset in the Boston is five to nine years and eight to thirteen years in the Chihuahua and Dachshund. The disease is similar to

Fuchs' dystrophy Fuchs dystrophy, also referred to as Fuchs endothelial corneal dystrophy (FECD) and Fuchs endothelial dystrophy (FED), is a slowly progressing corneal dystrophy that usually affects both eyes and is slightly more common in women than in men. Althou ...

in humans.

Commonly affected breeds

Many breeds are affected by corneal dystrophy with many different appearances. These breeds most commonly have these criteria. * Afghan Hound *

Airedale Terrier The Airedale Terrier (often shortened to "Airedale"), also called Bingley Terrier and Waterside Terrier, is a dog breed of the terrier type that originated in the valley (''dale'') of the River Aire, in the West Riding of Yorkshire, England. It ...

- occurs at 4 to 12 months of age in the central cornea. It is progressive and can cause decreased vision. *

Alaskan Malamute The Alaskan Malamute () is a large breed of dog that was originally bred for its strength and endurance to haul heavy freight as a sled dog and hound. It is similar to other arctic breeds such as the husky, the spitz, the Greenland Dog, Canad ...

- occurs at greater than two years of age in the central cornea. *

Beagle The beagle is a breed of small scent hound, similar in appearance to the much larger foxhound. The beagle was developed primarily for hunting hare, known as beagling. Possessing a great sense of smell and superior tracking instincts, th ...

- has a nebular, race track, or arcing appearance. *

Bearded Collie The Bearded Collie, or Beardie, is a herding breed of dog once used primarily by Scottish shepherds, but now mostly a popular family companion. Bearded Collies have an average weight of . Males are around tall at the withers while females are ...

- occurs at greater than one year of age in the lateral or central cornea and can affect just one eye. *

Bichon Frise A bichon is a distinct Dog type, type of toy dog; it is typically kept as a companion dog. Believed to be descended from the Barbet (dog), Barbet, it is believed the bichon-type dates to at least the 11th century; it was relatively common in 14t ...

- occurs at greater than two years of age in the inferior or central cornea. *

Boxer Boxer most commonly refers to: * Boxer (boxing), a competitor in the sport of boxing *Boxer (dog), a breed of dog Boxer or boxers may also refer to: Animal kingdom * Boxer crab * Boxer shrimp, a small group of decapod crustaceans * Boxer snipe ee ...

- occurs at greater than two years in the central cornea *

Cavalier King Charles Spaniel The Cavalier King Charles Spaniel is a British breed of toy dog of spaniel type. Four colours are recognised: Blenheim (chestnut and white), tricolour (black/white/tan), black and tan, and ruby; the coat is smooth and silky. The lifespan is u ...

- occurs at two to four years of age in the central cornea. *

American Cocker Spaniel The American Cocker Spaniel is a breed of sporting dog. It is a spaniel type dog that is closely related to the English Cocker Spaniel; the two breeds diverged during the 20th century due to differing breed standards in the US and the UK. In th ...

Rough Collie The Rough Collie (also known as the Long-Haired Collie) is a long-coated dog breed of medium to large size that, in its original form, was a type of collie used and bred for herding sheep in Scotland. More recent breeding has focused on the Co ...

- occurs at one to four years of age in the inferior or central cornea. * English Toy Spaniel - occurs at two to five years of age and has a crystalline, circular appearance. * German Shepherd Dog - occurs at one to six years of age and is usually oval. *

Golden Retriever The Golden Retriever is a Scottish breed of retriever dog of medium size. It is characterised by a gentle and affectionate nature and a striking golden coat. It is commonly kept as a pet and is among the most frequently registered breeds ...

- occurs at less than two years of age and can be progressive. *

Italian Greyhound The Italian Greyhound ( it, Piccolo levriero Italiano, italic=no) is an Italian breed of small sighthound. It may also be called the Italian Sighthound. History Small dogs of sighthound type have long been popular with nobility and royalty. ...

- occurs in young dogs and is focal. *

Lhasa Apso The Lhasa Apso ( ) is a non-sporting dog breed originating in Tibet. It has traditionally been used as an interior sentinel. Etymology Lhasa is the capital city of Tibet, and ''apso'' is a word from the Tibetan language. There is some deba ...

- oval appearance. *

Mastiff A mastiff is a large and powerful type of dog. Mastiffs are among the largest dogs, and typically have a short coat, a long low-set tail and large feet; the skull is large and bulky, the muzzle broad and short ( brachycephalic) and the ears dr ...

- oval appearance. *

Miniature Pinscher The Miniature Pinscher, also known as the Zwergpinscher and Mini Pin, is a small breed of dog of the pinscher type originating in Germany. The breed's earliest ancestors may have included the German Pinscher mixed with Italian greyhounds and dachs ...

- occurs at one to two years of age and is oval. *

Norwich Terrier The Norwich Terrier is a breed of dog originating in the United Kingdom, and was bred to hunt small rodents. With a friendly personality, Norwich Terriers are today mostly a companion dog breed. One of the smallest terriers, these dogs are gen ...

- peripheral cornea. *

Pembroke Welsh Corgi The Pembroke Welsh Corgi (; Welsh for "dwarf dog") is a cattle herding dog breed that originated in Pembrokeshire, Wales. It is one of two breeds known as a Welsh Corgi. Pembroke Welsh Corgis descended from the Spitz family of dogs. The other i ...

- occurs in young dogs and can include blood vessels and pigmentation. * Pointer - gray, hazy ring. *

Poodle The Poodle, called the Pudel in German and the Caniche in French, is a breed of water dog. The breed is divided into four varieties based on size, the Standard Poodle, Medium Poodle, Miniature Poodle and Toy Poodle, although the Medium Poodle var ...

- occurs at greater than one year of age. * Samoyed - occurs at six months to two years of age and is gray and round. *

Shetland Sheepdog The Shetland Sheepdog, often known as the Sheltie, is a breed of herding dog that originated in the Shetland Islands of Scotland. The original name was ''Shetland Collie,'' but this caused controversy amongst Rough Collie breeders of the time, so ...

- occurs at two to four years of age as multiple gray/white rings. It can develop into a

corneal ulcer Corneal ulcer is an inflammatory or, more seriously, infective condition of the cornea involving disruption of its epithelial layer with involvement of the corneal stroma. It is a common condition in humans particularly in the tropics and the a ...

. * Siberian Husky - occurs at five months to two years of age and is gray and oval. *

Weimaraner The Weimaraner ( ) is a large dog that was originally bred as a hunting dog in the early 19th century. Early Weimaraners were used by royalty for hunting large game such as boar, bear and deer. As the popularity of large game hunting began to ...

- occurs at one to eight years of age in the central cornea. *

Whippet The Whippet is a dog breed of medium size. It is a sighthound breed that originated in England, descended from the Greyhound. Whippets today still strongly resemble a smaller Greyhound. Part of the hound group, Whippets have relatively few ...

- occurs at three to five years of age in the central cornea.

References

{{DEFAULTSORT:Corneal dystrophies in dogs Dog diseases