Chronic superficial keratitis
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Chronic superficial keratitis (CSK), also known as pannus or Uberreiter’s disease, is an inflammatory condition of the cornea in dogs, particularly seen in the German Shepherd Dog.
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[edit] Affected breeds
Chronic superficial keratitis is most commonly seen in German Shepherd Dogs,[1] but it is also found in Belgian Tervurens, Greyhounds, Siberian Huskies, Australian Shepherds, and Border Collies.[2]
[edit] Cause
CSK is immune-mediated in nature, characterised by an infiltration of white blood cells into the superficial stroma of the cornea. These cells are predominately CD4-expressing T lymphocytes and to a lesser extent CD8-expressing T cells.[3] The CD4-expressing T-cells secrete gamma interferon, which causes expression of the major histocompatibility complex class II molecules in the cells of the cornea. These class II molecules cause further inflammation by interacting with the T cells and triggering an immune response.[4] Ultraviolet light is important in the genesis of the disease which is seen at higher prevalence at elevated altitude[5] and has a seasonal variation with most cases occurring in the summer. There is likely also a genetic component to the cause of CSK due to its predominance in certain breeds.
[edit] Signs and symptoms
CSK is usually a bilateral progressive condition. Signs include pigmentation and vascularization of the cornea (extension of blood vessels onto the cornea). It is usually first seen at the lateral (temporal) limbus (the junction between the cornea and sclera), although it eventually can extend from any part of the limbus to cover the entire cornea. Severe cases can cause blindness. Although CSK is usually identifiable by the appearance of the eye and the breed of the affected dog, cytology will reveal the presence of lymphocytes and plasma cells.[6]
[edit] Treatment
Treatment of CSK is usually with topical corticosteroids or topical cyclosporine, but any treatment only controls and reduces the inflammation rather than providing a cure.[7] Other investigated treatments include pimecrolimus, a derivative of ascomycin that interferes with T cell activation and inhibits the production of inflammatory cytokines.[8] Strontium-90 radiation therapy is also used to treat CSK.[9] Canine sunglasses have also been used to help protect the eyes of dogs with CSK to prevent further damage from ultraviolet radiation.[10]
[edit] References
- ^ Stanley R (1988). "Superficial stromal keratitis in the dog". Aust. Vet. J. 65 (10): 321–3. doi: . PMID 3058108.
- ^ Cornea. The Merck Veterinary Manual (2006). Retrieved on 2007-04-28.
- ^ Williams D (1999). "Histological and immunohistochemical evaluation of canine chronic superficial keratitis". Res. Vet. Sci. 67 (2): 191–5. doi: . PMID 10502491.
- ^ Williams D (2005). "Major histocompatibility class II expression in the normal canine cornea and in canine chronic superficial keratitis". Veterinary ophthalmology 8 (6): 395–400. doi: . PMID 16359362.
- ^ Chavkin M, Roberts S, Salman M, Severin G, Scholten N (1994). "Risk factors for development of chronic superficial keratitis in dogs". J. Am. Vet. Med. Assoc. 204 (10): 1630–4. PMID 8050943.
- ^ Gilger, B.C. (2006). Ocular Cytology - Your Key to Immediate Ocular Diagnosis. Proceedings of the North American Veterinary Conference. Retrieved on 2007-04-28.
- ^ Sapienza, John S. (2002). Corneal Diseases of Dogs and Cats. Proceedings of the 27th World Congress of the World Small Animal Veterinary Association. Retrieved on 2007-04-28.
- ^ Nell B, Walde I, Billich A, Vit P, Meingassner J (2005). "The effect of topical pimecrolimus on keratoconjunctivitis sicca and chronic superficial keratitis in dogs: results from an exploratory study". Veterinary ophthalmology 8 (1): 39–46. doi: . PMID 15644099.
- ^ Höcht S, Grüning G, Allgoewer I, Nausner M, Brunnberg L, Hinkelbein W (2002). "[Treatment of keratitis superficialis chronica of the dog with strontium 90]". Strahlentherapie und Onkologie : Organ der Deutschen Röntgengesellschaft ... [et al] 178 (2): 99–104. PMID 11942044.
- ^ Thornton, Kim Campbell (July 17, 2006). Shades for Scruffy? Canine eyewear not just for being a doggie diva. MSNBC. Retrieved on 2007-04-28.