Corneal dystrophies are a group of diseases that affect the cornea in dogs. [1]
Corneal dystrophies are a group of diseases that affect the cornea in dogs. [1]
Corneal dystrophy in dogs usually does not cause any problems and treatment is not required. [2] 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 is an age-related change that affects the inner layer of the corneal, the endothelium. 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 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. [3] The most commonly affected breeds are the Boston Terrier, Chihuahua, and Dachshund. [4] The age of onset in the Boston is five to nine years and eight to thirteen years in the Chihuahua and Dachshund. [5] The disease is similar to Fuchs' dystrophy in humans.
Many breeds are affected by corneal dystrophy with many different appearances. These breeds most commonly have these criteria. [4]
The dachshund, also known as the wiener dog or sausage dog, badger dog and doxie, is a short-legged, long-bodied, hound-type dog breed. The dog may be smooth-haired, wire-haired, or long-haired. Coloration varies.
The Shetland Sheepdog, also known as the Sheltie, is a breed of herding dog that originated in the Shetland Islands of Scotland. It was formally recognized by The Kennel Club in 1909. It was originally called the Shetland Collie, but this caused controversy amongst Rough Collie breeders of the time, so the name was changed. It is a small dog, clever, vocal, willing to please, and trustworthy.
The Cavalier King Charles Spaniel (CKCS) is a British breed of toy dog of spaniel type. Four colours are recognised: Blenheim, tricolour (black/white/tan), black and tan, and ruby; the coat is smooth and silky. The lifespan is usually between eight and twelve years.
The Cairn Terrier is a terrier breed originating in the Scottish Highlands and recognised as one of Scotland's earliest working dogs.
The corneal endothelium is a single layer of endothelial cells on the inner surface of the cornea. It faces the chamber formed between the cornea and the iris.
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. Although early signs of Fuchs dystrophy are sometimes seen in people in their 30s and 40s, the disease rarely affects vision until people reach their 50s and 60s.
A distichia is an eyelash that arises from an abnormal part of the eyelid. This abnormality, attributed to a genetic mutation, is known to affect dogs and humans. Distichiae usually exit from the duct of the meibomian gland at the eyelid margin. They are usually multiple, and sometimes more than one arises from a duct. They can affect either the upper or lower eyelid and are usually bilateral. The lower eyelids of dogs usually have no eyelashes.
A corneal ulcer, or ulcerative keratitis, is an inflammatory condition of the cornea involving loss of its outer layer. It is very common in dogs and is sometimes seen in cats. In veterinary medicine, the term corneal ulcer is a generic name for any condition involving the loss of the outer layer of the cornea, and as such is used to describe conditions with both inflammatory and traumatic causes.
Corneal dystrophy is a group of rare hereditary disorders characterised by bilateral abnormal deposition of substances in the transparent front part of the eye called the cornea.
Follicular dysplasia is a genetic disease of dogs causing alopecia, also called hair loss. It is caused by hair follicles that are misfunctioning due to structural abnormality. There are several types, some affecting only certain breeds. Diagnosis is achieved through a biopsy, and treatment is rarely successful. Certain breeds, such as the Mexican Hairless Dog and Chinese Crested Dog, are bred specifically for alopecia.
Progressive retinal atrophy (PRA) is a group of genetic diseases seen in certain breeds of dogs and, more rarely, cats. Similar to retinitis pigmentosa in humans, it is characterized by the bilateral degeneration of the retina, causing progressive vision loss culminating in blindness. The condition in nearly all breeds is inherited as an autosomal recessive trait, with the exception of the Siberian Husky (inherited as an X chromosome linked trait) and the Bullmastiff (inherited as an autosomal dominant trait). There is no treatment.
Retinal dysplasia is an eye disease affecting the retina of animals and, less commonly, humans. It is usually a nonprogressive disease and can be caused by viral infections, drugs, vitamin A deficiency, or genetic defects. Retinal dysplasia is characterized by folds or rosettes of the retinal tissue.
Persistent pupillary membrane (PPM) is a condition of the eye involving remnants of a fetal membrane that persist as strands of tissue crossing the pupil. The pupillary membrane in mammals exists in the fetus as a source of blood supply for the lens. It normally atrophies from the time of birth to the age of four to eight weeks. PPM occurs when this atrophy is incomplete. It generally does not cause any symptoms. The strands can connect to the cornea or lens, but most commonly to other parts of the iris. Attachment to the cornea can cause small corneal opacities, while attachment to the lens can cause small cataracts. Using topical atropine to dilate the pupil may help break down PPMs.
Band keratopathy is a corneal disease derived from the appearance of calcium on the central cornea. This is an example of metastatic calcification, which by definition, occurs in the presence of hypercalcemia.
Bullous keratopathy, also known as pseudophakic bullous keratopathy (PBK), is a pathological condition in which small vesicles, or bullae, are formed in the cornea due to endothelial dysfunction.
Congenital hereditary corneal dystrophy (CHED) is a form of corneal endothelial dystrophy that presents at birth.
Feline corneal sequestrum is the development of dark areas of dead tissue in the cornea of domestic cats. This disease is painful to the cat, although it develops slowly over a longer period of time. Cats will usually demonstrate teary eye(s), squinting or closing of the eye(s), and covering of the third eyelid.
Corneal opacification is a term used when the human cornea loses its transparency. The term corneal opacity is used particularly for the loss of transparency of cornea due to scarring. Transparency of the cornea is dependent on the uniform diameter and the regular spacing and arrangement of the collagen fibrils within the stroma. Alterations in the spacing of collagen fibrils in a variety of conditions including corneal edema, scars, and macular corneal dystrophy is clinically manifested as corneal opacity. The term corneal blindness is commonly used to describe blindness due to corneal opacity.
Exposure keratopathy is medical condition affecting the cornea of eyes. It can lead to corneal ulceration and permanent loss of vision due to corneal opacity.