Contributors: Dennis E Brooks, David L Williams

 Species: Canine   |   Classification: Diseases

Introduction Pathogenesis Diagnosis Treatment Outcomes Further Reading

Introduction

  • Inflammation of the uveal tract (iris, ciliary body and choroid).
  • Cause: infection (eg viral, bacterial, parasitic, fungal), trauma, lens damage, immune-mediated.
  • Signs: severe pain, hyphemia, miosis, cloudy cornea, conjunctival hyperemia.
  • Treatment: medical - many approaches.
  • Prognosis: serious consequences if disease is uncontrolled.
    Follow the diagnostic tree on Anterior Uveitis Anterior Uveitis.

Presenting Signs

  • Ocular pain.
  • Red eye (episcleral congestion).
  • Lacrimation.
  • Corneal edema.
  • Cloudy eye.
  • Iris color change.

Geographic Incidence

  • Common, although true incidence is unknown.
  • Fungal and rickettsia diseases vary with location.

Cost Considerations

  • If surgery or specialist referral required.
  • Medical treatment only is usually sufficient.

Pathogenesis

Etiology

  • Often undetermined.
  • Reflex uveitis Reflex uveitis.
  • Systemic viral disease, eg infectious canine hepatitis Canine adenovirus type 1 disease with corneal opacity, very common.
  • Systemic bacterial disease, eg leptospirosis Leptospirosis , brucellosis Brucellosis , Lyme disease Arthritis: borrelial , tuberculosis Pulmonary tuberculosis.
  • Local bacterial disease, eg pasteurellosis, staphyloccocal infection (toxins).
  • Septic bacterial focus, eg pyometra Pyometra.
  • Parasitic, eg toxoplasmosis Toxoplasmosis , leishmaniasis Canine leishmaniosis (imported animals?).
  • Mycotic infection, eg cryptococcosis , blastomycosis, histoplasmosis. Rare in temperate climate/country.
  • Neoplasia - primary or secondary. Lymphoma is most common.
  • Trauma, eg blunt or sharp injury or foreign bodies.
  • Primary lens damage to expose lens proteins to aqueous.
  • Diabetes.
  • Lens-induced uveitis from cataract formation.
  • Systemic hypertension.
  • Auto-immune, eg uveodermatological syndrome. VKH syndrome.
  • Rickettsial diseases, eg Ehlichiosis Ehrlichiosis , Rocky Mountain spotted fever.
  • Immune-mediated.
  • Hypermature cataracts cause lens proteins to elicit inflammation.

Pathophysiology

  • Inflammation of uveal tract may involve iris (iritis), ciliary body (cyclitis), or choroid (choroiditis).
  • More commonly involves all 3 (panuveitis).
  • Breakdown of the blood-aqueous barrier causes anterior uveal tissue destruction.
  • Increased vascular permeability is mediated by histamine, serotonin, prostaglandins and leukotrines, and causes extravasation of plasma proteins, cells and fluid.
  • Iridal congestion, aqueous flare, hypopyon, keratitic precipitates and corneal edema develop along with cellular infiltration.
  • Inflammation causes muscular spasm giving miosis and pain.

Timecourse

  • Anterior uveitis therapy should last at least 2 months as the blood-aqueous barrier remains disrupted for about 8 weeks after insult.

Diagnosis

Presenting Problems

  • Red eye.
  • Ocular pain.

Client History

  • Ocular pain.
  • Red eye.
  • Lacrimation.
  • Miosis.
  • Signs related to systemic disease.
  • Ocular opacity.
  • Iris color change.

Clinical Signs

  • Episcleral congestion.
  • Ocular pain - blepharospasm, photophobia.
  • Miosis.
  • Swollen, dull iris with loss of fine detail.
  • Iris color change.
  • Conjunctival hyperemia.
  • Sluggish pupillary movement.
  • Aqueous flare (due to fibrin or cells in aqueous chamber).
  • Decreased intraocular pressure.
  • Corneal opacity Lenticular opacity temporary - Miniature Long-haired Dachshund 13 weeks.
  • Synechiae Posterior synechiae Standard Schnauzer female 14 years.
  • Hyphema Hyphema Chihuahua 7 years.
  • Deep corneal vascularization.
  • Keratic precipitates on posterior surface of cornea.
  • Foreign body in anterior chamber.
  • Aqueous loss.

Diagnostic Investigation


Other
  • Ophthalmoscopy:
    • Illumination anterior chamber from lateral to medial - for shallow anterior chamber due to swollen iris.
    • Retinal signs of systemic disease, chorioretinitis.
  • Tonometry.
  • Gonioscopy.
Serology2-D Ultrasonography
  • For neoplasia.
Hematology
  • To rule out systemic infectious focus, eg pyometra.
Biochemistry

Gross Autopsy Findings

  • The eye is inflamed with conjunctival hyperemia, episcleral congestion, corneal edema, aqueous flare and variable vision.

Histopathology Findings

  • Iris and ciliary body infiltrated with a mixture of inflammatory or neoplastic cell types, depending on the cause and chronicity of the disease.

Differential Diagnosis

Treatment

Initial Symptomatic Treatment

  • Removal of foreign body.
  • Repair corneal tears.
    Consider referral to specialist if foreign body present.
  • Topical corticosteroids:
    EitherPrednisolone acetate Prednisolone 1% - has best intraocular penetration.
    OrBetamethasone sodium phosphate Betamethasone 0.1%.
    OrDexamethasone Dexamethasone 0.1%.
  • Topical mydriatics, eg atropine sulfate Atropine 1% - to decrease ciliary spasm → decreased pain: moderate pupil dilation → decreased synechiae formation.
  • Ensure that pupil is opening during the first consultation.

    Treat for up to 10 days after resolution of uveitis

    Use mydratics with care if secondary glaucoma

EitherSystemic corticosteroid.
OrSystemic non-steroidal anti-inflammatory drug (NSAID), eg carprofen Carprofen.

Standard Treatment

  • Treat any underlying disease.

Monitoring

  • Patients with severe anterior uveitis should be hospitalized for intial diagnostic workup and medical management.

Subsequent Management

Monitoring

  • Tonometry for elevated IOPor to assess improvement, ie reduced IOP in uveitis.
    Concurrent use of systemic corticosteroids and NSAIDs → risk of gastrointestinal side-effects.

Outcomes

Prognosis

  • Variable depending on etiology.
  • Early, aggresive medical therapy and a thorough diagnostic workup are required.

Expected Response to Treatment

  • Decreased ocular pain.
  • Easily dilated pupil.
  • Reduced flare and corneal edema.

Reasons for Treatment Failure

  • Complications, eg blindness, synechiae, hypopyon, hyphema, retinal detachment, secondary glaucoma, corneal edema, lens luxation, cataract formation, permanent vitreal opacities, iris bombe, optic neuritis/atrophy.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Michau T M, Breitschwerdt E B, Gilger B C et al (2003) Bartonella vinsonii subspecies berkhoffi as a possible cause of anterior uveitis and choroiditis in a dog. Vet Ophthalmol (4), 299-304 PubMed.
  • Sansom J (2000) Diseases involving the anterior chamber of the dog and cat. In Practice 22 (2), 58-70 VetMedResource.
  • Huss B T, Collier L L, Collins B K et al (1994) Polyarthropathy and chonoretinitis with retinal detachment in a dog with systemic histoplasmosis. JAAHA 30 (3), 217-224 VetMedResource.
  • Håkanson N & Forrester S D (1990) Uveitis in the dog and cat. Vet Clin North Am Small Anim Pract 20 (3), 715-35 PubMed.
  • Crispin S M (1988) Uveitis in the dog and cat. JSAP 29 (7), 429-447 PubMed.

Other Sources of Information