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=Immune-mediated uveitis/recurrent uveitis=
==Introduction==
Uveitis is a very important disease. It can be secondary to keratitis, but is common as a primary immune-mediated disorder. The
major problem is its tendency to recur, causing progressive loss of vision. This is the most common cause of blindness.
The causative agent is unknown but several are implicated, such as ''Onchocerca'' and ''leptospira''. Regardless of the cause, the treatment is as for uveitis which gives effective, immediate results.
==Clinical Signs==
* The acute stage is '''intensely painful''', showing excessive '''lacrimation and photophobia'''
* '''Corneal oedema''' is a characteristic finding
* '''Ciliary and conjunctival injection''' with '''peripheral corneal vascularisation''' is also seen
* More serious findings are '''aqueous flare and hypopyon'''
* '''Miosis''' is always present. Following repeated episodes there may be synechiae, which prevent papillary dilatation in response to mydriatics
* '''Chronic uveitis''' results in shrinking of the globe, cataracts and depigmentation of the fundus around the optic nerve
==Diagnosis==
* If diagnosis is attempted, then '''routine blood tests''' should be run along with '''titres for [[Spirochaetes#Leptospira|leptospirosis]] and [[Brucella species|brucellosis]], [[Equine Herpesvirus 1|equine herpes virus]], [[Streptococci#Strangles|strangles]] and [[Donkey - Equine Viral Arteritis|equine viral arteritis]].
* '''Conjunctival biopsy''' will diagnose the presence of ''Onchocerca''
==Treatment==
'''Systemic [[Anti-Inflammatory Drugs|anti-inflammatory]] treatment is needed urgently''' to reduce the pain and inflammation. [[Steroids|Corticosteroids]] have been recommended and do work, but the risk of complications makes an [[NSAIDs|NSAID]], such as flunixin meglumine, the drug of choice.
* '''Flunixin meglumine''' is given every 12 hours for at least five days but should be continued until clinical signs resolve
* If [[NSAIDs]] need to be continued for a long period, then a transfer to '''phenylbutazone''' will reduce the risk of side effects
* '''Topical [[NSAIDs]]''' are effective in relieving pain short-term: flurbiprofen 0.03% or suprofen 1% ophthalmic solution
* '''Topical [[Steroids|corticosteroids]] are safer than systemic but must only be used if corneal integrity is 100%
* Whilst using [[Steroids|steroids]], '''regular fluorescein staining''' must be used to check for ulceration
* If uncomplicated immune-mediated uveitis is diagnosed with certainty, long term topical corticosteroids are recommended, e.g. four weeks
* Topical '''atropine drops''' (1-2%) should be applied hourly until mydriasis occurs and then twice daily until the acute inflammatory response has subsided, possibly for up to two weeks. Monitor for gut function as long-term atropine slows gut movement
* '''Cyclosporin''' 2% is an ocular immunomodulator, which can produce excellent results but only in about 50% of cases. It can be used to replace corticosteroids if corneal ulceration is present. A ten-day course given at twelve-hourly intervals is recommended
==References==
* Svendsen, E.D., Duncan, J. and Hadrill, D. (2008) ''The Professional Handbook of the Donkey'', 4th edition, Whittet Books
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