Go Pets AmericaGo Pets America
  Dogs | Cats | Birds | Fish | Horses | Reptiles | Small Pets | Animals | Jobs | Pics | Videos | Garden | Biology | Message Board 
Home » Diseases & Disorders » Panuveitis
  Search Go Pets America  

Panuveitis

The outer layer of the eyeball is the tough sclera, the inner coat is the thin retina, and the middle layer is the uvea. The uvea is composed of the choroid (a layer rich in blood vessels that supply the eye with oxygen and nutrients), and the ciliary body (an area toward the front of the eye where the choroid thickens), and the iris (which gives the eye color and in the center of which is an opening, the pupil, which looks like a black disc). Inflammation of any part of the uvea is called uveitis.4 Uveitis may occur following surgical or traumatic injury to the eye; as a component of an autoimmune disorder, i. e. rheumatoid arthritis, Behcet's disease, spondylosis, sarcoidosis; as an isolated immune mediated ocular disorder, i. e. pars planitis, iridocyclitis etc., unassociated with known causes; and following certain systemic diseases which cause antibody-antigen complexes to be deposited in the uveal tissues. Together these disorders represent the non-infectious types of uveitis.10

Panuveitis is inflammation of the entire uveal tract. It is commonly caused by bacterial infections, especially with spirochetes (Lyme borreliosis and syphilis), viral infections (CMV and HIV), autoimmune reactions caused by autoantigens of the eye, chronic granulomatous diseases and vasculitis.1. Bacterial infections that most often cause panuveitis include blastomycosis, coccidioidomycosis, leptospirosis, canine monocytic ehrlichiosis (CME) and cryptococcosis.5 When caused by bacterial infections it is often referred to as bacterial endophthalmitis, this is seen most commonly with sarcoidosis, syphilis, toxoplasmosis and Behçet's disease.2

Toxoplasmosis is the leading cause of posterior uveitis, being more common in children than adults, and accounting 70% of pediatric posterior and panuveitis.7

Panuveitis may also be clinically inapparent but detectable at histopathology (study of diseased or abnormal tissues).

Panuveitis in Animals

Canine uveodermatologic syndrome a rare condition that is thought to represent an autoimmune attack against melanocytes (the human counterpart condition is Vogt-Koyanagi-Harad [VKH] syndrome). Heavily pigmented tissues such as the uveal tract, skin, and mucous membranes are primarily involved. This condition often causes panuveitis in dogs. If a dog has protothecosis, panuveitis may affect both eyes and is often blinding. In case of canine herpesvirus infection, which is almost exclusively a fatal disease of newborn puppies, panuveitis affects both eyes and is accompanied by keratitis, cataracts and retinal detachment.6

Conventional & Alternative Treatment

Curative treatment is given in the case of an infectious cause. The prognosis for vision depends on the disease in each case, but is often poor.3 Both topical and oral corticosteroids will be required for the treatment of panuveitis and for immune-mediated types of uveitis.8 These are used at the anti-inflammatory level to help resolve panuveitis and optic nerve injury in addition to orbital inflammation and swelling.9

Glucocorticoids are an important part of treatment in severe anterior, intermediate, posterior, and panuveitis. A major problem with present drug therapy is the inability to achieve adequate intraocular drug concentration. In particular, uveitis is well known for its long duration due in part to the difficulties associated with poor intraocular penetration of topical medications into the posterior segment. Systemic glucocorticoid administration may require prolonged exposure of high plasma concentrations. These high drug plasma levels often lead to systemic side effects such as hypertension, hyperglycemia, increased susceptibility to infection, peptic ulcers, psychosis, and other complications. 11

Azathioprine is a drug that suppresses inflammation by tamping down the immune system. It is approved for use in the treatment of rheumatoid arthritis and for preventing rejection of transplanted organs. An article from the Brown University Medical School notes that azathioprine is specifically recommended for chronic uveitis, particularly in conjunction with oral corticosteroids.4

References
  1. Color atlas of immunology. Gerd-RĂ¼diger Burmester, Antonio Pezzutto, Timo Ulrichs, Alexandra Aicher
  2. Samter's immunologic diseases, Volume 1. Karl Frank Austen
  3. Pocket atlas of ophthalmology. Torsten Schlote, Faik Gelisken
  4. Prescription Drugs: Alternative Uses, Alternative cures. Kevin Loughlin, M.D., Joyce Generali, M.S., R.Ph.
  5. Small animal ophthalmology secrets. Ronald C. Riis
  6. Essentials of veterinary ophthalmology. Kirk N. Gelatt
  7. Pediatric Retina: Medical and Surgical Approaches. Mary Elizabeth Hartnett, Michael Trese, Antonio Capone
  8. Notes on veterinary ophthalmology. Sheila M. Crispin
  9. Small animal ophthalmology secrets. Ronald C. Riis
  10. Ocular Treatment Using Cyclosporin-A Derivatives. Garst Michael
  11. Methods for treating inflammation of the eye. Wong Vernon, Hu Mae W L.

Comments



Leave a comment    







Pets   Jobs    Contact Us    Terms of Use    Search    Advertise   
©2013 Go Pets America, Inc. All Rights Reserved.