Disorders Of Anterior Uvea 2 Flashcards
Uveitis
Inflammation to any aspect of the uveal tract
• Anterior uveitis - iris + ciliary body
• Posterior uveitis - choroid
• Panuveitis - all three portions
Ocular signs of uveitis
Blepharospasm - squinting
• Episcleral injection,
• Ciliary flush
• Corneal edema
• Miosis
• Synechiae
• Aqueous flare
• Hyphema
• Hypopyon
• Keratic precipitates
• Rubiosis iridis
• Hypotony
Episceral injection
Congestion of the vessels
Ciliary flush
360 degree corneal vascularization
Red appearence around eye, vessels are usually deep, brush like appearence
- indicative of intra ocular disease**
Corneal edema
Fluid build up within stromal layer
Blue eye appearence
Miosis
Pupillary constriction
Synechiae
Adherence of iris to cornea (anterior) or lens (posterior)
Anterior is Common w full thickness perforation of cornea
Posterior is common in uveitis
Aqueous flare
Release of protein into the aqueous humor - breakdown of blood aqueous barrier
Leads to cloudy & protrusion of anterior chamber
Lipemic aqueous
Unique manifestation of uveitis - presence of lipids
Keratic precipitates
Accumulation of inflammatory cells that adhere to corneal endothelium (inner layer)
Common in cats
Hypopyon
Accumulation of inflammatory cells (pus) in the anterior chamber -
Hyphema
Accumulation of blood in the eye - any chamber but in the eye
Rubeosis iridis
Red iris - congestion of iridal vasculature
Hypotony
Low Intraocular pressure
Uveitis complications
Synechiae - adhesion of lens and iris
• Glaucoma
• Iris bombe
• Cataract -
• Lens instability - break down of zonular fibers
• Retinal detachment
• Phthisis bulbi
List builds /can progress from one disease to the next on the list
Mechanism 1 of uveitis to glaucoma
Obstruction of the angle by inflammatory debris
Mechanism 2 of uveitis to glaucoma
Formation of Pre-iridal fibrovascular membnrane, lead by inflammatory cells. Drainage is compromised
Mechanism 3 of uveitis to glaucoma
Iris Bombe + peripheral anterior synechiae
Accumulation of aqueous humor behind iris due to blocked drainage in eye
Causes of uveitis
Primary ocular disease
Idiopathic
Trauma
Ocular manifestations of systemic diseases
Primary ocular disease
Cataract
Lens rupture
Corneal ulcer
Ocular manifestations of systemic diseases
Infectious
Metabolic
Immune-mediated
Neoplasia
What percentage of dogs and cats are idiopathic?
Dogs - 47%
Cats - 70%
Lens induced uveitis
Phacolytic Uveitis - Soluble lens protein leaks through an intact lens capsule (cataract) Phacoclastic uveitis - Sudden exposure of intact lens protein (lens capsule tear - trauma)
Common causes of uveitis in dogs
Infectious
Lens induced uveitis - 2 types
Reflex uveitis - Corneal/ scleral diseases
Metabolic - Hyperlipidemia
Breed specific
Common causes of uveitis in cats
Infectious - Viral (FeLV, FIP, FIV, FHV-1), Bacterial (Bartonella), Fungal (Histoplasma, Blastomyces, Coccidioides), Protozoal (Toxoplasma)
• Metabolic - Systemic hypertension
• Neoplastic - Lymphoma - most common metastatic
Common causes of uveitis for horses
Trauma
• Reflex uveitis - Stromal abscess
• Equine Recurrence Uveitis (ERU)
• Systemic disease - Sepsis in foals, EIA , Potomac Horse Fever etc
Equine recurrence uveitis
Most common cause of blindness in horses - suspect immune mediated cause
Classifications for ERU
Classic - active bouts w quiet periods
Insidious - on going/low grade
Posterior - only choroid affected
Breeds common w ERU
Appaloosa, draft, warm blood, Icelandic horses
treatment for ERU
Supportive, surgical - implant, vitrectomy, Intravitreal infection
DX uveitis
History - Vaccination, Life style (indoor/outdoor/travel), Acute/chronic, Previous meds
• Physical Exam - Ophthalmic Exam
• Minimum data base
• CBC, chemistry panel, UA
Specific DX for uveitis
Initial serology
• Canine: fungal, tick titers, toxoplasmosis
• Feline: fungal, FeLV, FIV, FIP, toxoplasmosis
• Thoracic radiographs and abdominal ultrasound- fungal/neoplasia is suspected
• Ocular ultrasound: ONLY if you cannot see past the iris and lens
• Additional systemic testing as indicated by species/patient clinical signs/geographic area
TX goals for uveitis
Prevent sequalae
• Eliminate intraocular inflammation
• Stabilize and restore blood - aqueous barrier
• Treat underlying cause when possible!!! Supportive
Treating uveitis
Topical anti-inflammatories
• Corticosteroids - Prednisolone acetate, Dexamethasone
• Non-steroidal anti-inflammatories - Diclofenac, Flurbiprofen, Ketorolac
• Systemic anti-inflammatories
• Corticosteroids - Prednisone • Non-steroidal anti-inflammatories
Topical atropine
Most efficient pain management for the eye
Mydriatic (synechia), Cycloplegic (analgesia)
• Stabilize blood-aqueous barrier
• Systemic therapy if indicated
• Antimicrobials
• Antifungals
Contradictions for atropine
Contraindications
• Lens instability
• Glaucoma
• Dry eye • Parasympatholytic - decrease STT
• Bitter taste (CATS)
Contractions for topical & systemic steroids
Topical
• Potentiate infection - melting ulcer
• Decrease would healing
• Corneal degeneration - consider switching to a topical NSAID long-term
• Systemic
• Depends on underlying disease
• Rule out infectious causes!
