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Basics ⬇

Basics

Definition

  • Inflammation of the anterior uveal tissues, including iris (iritis), ciliary body (cyclitis), or both (iridocyclitis).
  • May be associated with concurrent posterior uveal and retinal inflammation (choroiditis; chorioretinitis).
  • May be unilateral or bilateral.

Pathophysiology

  • Increased permeability of the blood-aqueous barrier related to infectious, immune- mediated, traumatic, or other causes allows entrance of plasma proteins and blood cellular components into aqueous humor.
  • Disruption of blood-aqueous barrier is initiated and maintained by numerous chemical mediators, including histamine, prostaglandins, leukotrienes, serotonin, kinins, and complement.

Systems Affected

  • Ophthalmic.
  • Other systems may also be affected by underlying disease process.

Incidence/Prevalence

  • Relatively common condition.
  • True incidence/prevalence unknown.

Geographic Distribution

Geographic location may affect incidence of certain infectious causes of uveitis.

Signalment

Species

Dog

Breed Predilections

  • None for most causes.
  • Uveitis associated with iridociliary cysts in golden retriever (a.k.a. golden retriever uveitis, pigmentary uveitis).
  • Increased incidence of uveodermatologic syndrome in Siberian husky, Akita, Samoyed, and Shetland sheepdog.

Mean Age and Range

  • Any age may be affected.
  • Mean age in uveodermatologic syndrome-2.8 years.
  • Mean age in golden retriever uveitis-8.6 years.

Signs

Historical Findings

  • Red eye-due to conjunctival hyperemia and ciliary flush.
  • Cloudy eye-due to corneal edema, aqueous flare, hypopyon, etc.
  • Painful eye-manifest by blepharospasm, photophobia, or rubbing eye.
  • Vision loss-variable.

Physical Examination Findings

The importance of a thorough physical examination in dogs presenting with uveitis cannot be overstated.

Ophthalmic Findings

  • Ocular discomfort-manifest by blepharospasm, photophobia, and rubbing eye.
  • Ocular discharge-usually serous; sometimes mucoid to mucopurulent.
  • Conjunctival hyperemia-bulbar and palpebral conjunctiva both usually affected.
  • Corneal edema-diffuse; mild to severe.
  • Keratic precipitates-multifocal aggregates of inflammatory cells adherent to corneal endothelium; most notable ventrally.
  • Aqueous flare and cells-cloudiness of aqueous humor due to increased protein content and suspended cellular debris; best visualized with a bright, narrow beam of light shined through anterior chamber.
  • Ciliary flush-injection of deep perilimbal anterior ciliary vessels.
  • Deep corneal vascularization-circumcorneal distribution (brush border).
  • Miosis and/or resistance to pharmacologic dilation.
  • Iridal swelling.
  • Reduced IOP is consistent with uveitis but is not a uniform finding.
  • Posterior synechia-adhesions between posterior iris and anterior lens surface.
  • Fibrin in anterior chamber.
  • Hypopyon or hyphema-accumulations of white blood cells or red blood cells, respectively, in the anterior chamber; usually settles horizontally in ventral aspect of chamber but may be diffuse.
  • Chronic changes may include rubeosis iridis, iridal hyperpigmentation, secondary cataract, lens luxation, pupillary seclusion, iris bombé, secondary glaucoma, and phthisis bulbi.

Causes

  • Infectious-mycotic (Blastomyces dermatitidis, Cryptococcus neoformans, Coccidiodes immitis, Histoplasma capsulatum); protozoal (Toxoplasma gondii, Neospora caninum, Leishmania donovani); rickettsial (Ehrlichia canis, Rickettsia rickettsii); bacterial (Leptospira spp., Bartonella spp., Brucella canis, Borrelia burgdorferi, any bacterial septicemia); algal (Prototheca spp.); viral (adenovirus, distemper, rabies, herpes); parasitic (ocular filariasis, ocular larval migrans).
  • Immune-mediated-reaction to lens proteins (due to cataract or lens trauma); uveodermatologic syndrome; post-vaccinal reaction to canine adenovirus vaccine; vasculitis.
  • Neoplastic-primary ocular tumors (especially uveal melanoma, iridociliary adenoma/adenocarcinoma); metastasis to uveal tract (lymphosarcoma most common).
  • Metabolic-hyperlipidemia; hyperviscosity; systemic hypertension.
  • Miscellaneous-idiopathic; trauma; pigmentary uveitis of golden retrievers; ulcerative keratitis; corneal stromal abscess; scleritis; lens instability/luxation; dental/periodontal disease; toxemia.

Risk Factors

None specific; immune suppression and geographic location may increase incidence of certain infectious causes of uveitis; breed predispositions should be considered.

Diagnosis ⬆ ⬇

Diagnosis

Differential Diagnosis

  • Conjunctivitis-redness limited to conjunctival hyperemia (i.e., no ciliary flush); ocular discharge usually thicker and more copious than in uveitis; discomfort may be alleviated with application of topical anesthetic.
  • Glaucoma-elevated IOP is most consistent feature of this disease; others may include dilated pupil, Haab's striae, and buphthalmos.
  • Lens luxation-corneal edema may be localized to site of lens contact with endothelium or may be diffuse as a result of associated uveitis and/or glaucoma; lens luxation is highly breed associated.
  • Ulcerative keratitis-corneal fluorescein staining will detect ulcers; corneal edema associated with ulcers is either localized to, or most severe at, site of ulcer; ocular discharge often thicker and more copious than with uveitis; discomfort may be partially alleviated by topical anesthetic.
  • Corneal endothelial dystrophy or degeneration-diffuse corneal edema is present, but IOP is normal; conjunctival hyperemia and signs of ocular discomfort are generally absent.
  • Horner's syndrome-miosis, enophthalmos, and nictitans protrusion are similar in both conditions, but Horner's is non-painful with no ocular discharge; ptosis with Horner's is distinguished from blepharospasm as the latter is an active process; minor conjunctival hyperemia may be noted with Horner's, but cornea and anterior chamber are clear; clinical signs of Horner's syndrome resolve following topical application of 1–10% phenylephrine.

CBC/Biochemistry/Urinalysis

Often normal; changes related to underlying disease may be present.

Other Laboratory Tests

  • Serology for infectious diseases listed under “Causes” may be appropriate, depending on index of suspicion for infectious etiology.
  • Clinical signs raising the suspicion of systemic disease including lethargy, pyrexia, weight loss, coughing, lymphadenopathy, etc., warrant serology for infectious diseases.

Imaging

  • Thoracic radiography may show evidence of causative disease process (e.g., systemic mycoses; metastatic neoplasia).
  • Abdominal ultrasound may be warranted if suspicion for metastatic neoplastic disease is high.
  • Ocular ultrasound is indicated if opacity of ocular media precludes direct examination; may reveal intraocular neoplasm or retinal detachment.

Diagnostic Procedures

  • Tonometry-low IOP consistent with uveitis; elevated IOP indicates glaucoma (primary disease or secondary to uveitis).
  • Lymph node aspirates-if enlarged nodes are palpable, aspiration for cytology is indicated.
  • Ocular centesis-if retinal detachment is present, cytology of subretinal aspirate may reveal causative agents; anterior chamber centesis is generally unrewarding.

Pathologic Findings

  • Gross-see “Physical Examination Findings.”
  • Histopathologic-corneal edema; peripheral corneal deep stromal vascularization; keratic precipitates; preiridal fibrovascular membrane; peripheral anterior synechia; posterior synechia; entropion or ectropion uveae; leukocyte accumulation in iris, ciliary body, sclera, choroid (lymphocytic, plasmacytic, suppurative, or granulomatous infiltrates, depending on etiology); secondary cataract; with posterior segment involvement in inflammatory process, cyclitic membrane; vitreal traction bands and retinal detachment may be present.

Treatment ⬆ ⬇

Treatment

Appropriate Health Care

Outpatient medical management is generally sufficient.

Nursing Care

None

Activity

  • No changes indicated in most cases.
  • Reduced exposure to bright light may alleviate discomfort.

Diet

No changes indicated.

Client Education

  • Inform of potential systemic diseases causing ophthalmic signs and emphasize importance of appropriate diagnostic testing.
  • In addition to symptomatic uveitis treatment, treatment of underlying disease (when possible) is paramount to a positive outcome.
  • Inform of potential complications and emphasize compliance with treatment and follow-up recommendations that will reduce the likelihood of complications.

Surgical Considerations

None in most cases. Specific instances requiring surgical intervention include removal of ruptured lenses, removal of cataracts causing uveitis (if prognosis for successful surgery is otherwise favorable), and surgical management of secondary glaucoma.

Medications ⬆ ⬇

Medications

Drug(s) Of Choice

Corticosteroids

Topical

  • Prednisolone acetate 1% apply 2–8 times daily, depending on severity of disease; taper medication as condition resolves.
  • Dexamethasone 0.1%-apply 2–8 times daily, depending on severity of disease; taper medication as condition resolves.
  • Other topical corticosteroids (e.g., betamethasone, hydrocortisone) are considerably less effective in the treatment of intraocular inflammation.
  • Taper treatment frequency over several weeks as condition improves; stopping topical corticosteroids abruptly may result in rebound of ocular inflammation.

Subconjunctival

  • Triamcinolone acetonide 4–6 mg by subconjunctival injection.
  • Methylprednisolone 3–10 mg by subconjunctival injection.
  • Often not required.
  • Indicated only in severe cases as one-time injection followed by topical and/or systemic anti-inflammatories.

Systemic

  • Prednisone 0.5–2.2 mg/kg/day initially; taper dose after 7–10 days.
  • Use only if systemic infectious causes of uveitis have been ruled out.

Nonsteroidal Anti-inflammatory Drugs

Topical

  • Less effective than topical corticosteroids.
  • Flurbiprofen-apply 2–4 times daily, depending on severity of disease.
  • Diclofenac-apply 2–4 times daily, depending on severity of disease.

Systemic

  • Do not use concurrently with systemic corticosteroids; avoid in the presence of hyphema.
  • Carprofen 2.2 mg/kg PO q12h or 4.4 mg/kg PO q24h.
  • Tepoxalin 10 mg/kg PO q24h.
  • Meloxicam 0.2 mg/kg PO q24h.
  • Firocoxib 5 mg/kg PO q24h.

Topical Mydriatic/Cycloplegic

  • Atropine sulfate 1%-apply 1–4 times daily, depending on severity of disease. Use lowest frequency adequate to maintain dilated pupil and ocular comfort; taper medication as condition resolves.

Contraindications

  • Avoid the use of miotic medications (e.g., pilocarpine, demecarium bromide), including topical prostaglandins (e.g., latanoprost), in the presence of uveitis.
  • Topical and subconjunctival corticosteroids are contraindicated in ulcerative keratitis.
  • Avoid systemic corticosteroids in dogs with systemic hypertension or systemic infections.

Precautions

Out of concern for secondary glaucoma, topical atropine should be used judiciously and IOP should be monitored periodically.

Possible Interactions

Systemic corticosteroids and NSAIDS should not be used concurrently.

Alternative Drug(s)

N/A

Follow-Up ⬆ ⬇

Follow-Up

Patient Monitoring

Recheck in 3–7 days, depending on severity of disease. IOP should be monitored at recheck to detect secondary glaucoma. Frequency of subsequent rechecks dictated by severity of disease and response to treatment.

Possible Complications

  • Many systemic complications, including death, may occur due to systemic etiology of uveitis.
  • Ophthalmic complications include secondary cataract, secondary glaucoma, lens luxation, retinal detachment, phthisis bulbi.

Expected Course and Prognosis

Extremely variable; depends on underlying disease and response to treatment.

Miscellaneous ⬆

Miscellaneous

Zoonotic Potential

None in most cases. Some forms of systemic infection causing uveitis may pose a slight risk to immune-compromised owners.

Pregnancy/Fertility/Breeding

Avoid systemic corticosteroids. Because of possibility of systemic absorption, topical corticosteroids may also pose risk, especially with frequent application in small dogs.

Synonyms

Iridocyclitis

See Also

Red Eye

Abbreviations

  • IOP = intraocular pressure
  • NSAID = nonsteroidal anti-inflammatory drug

Suggested Reading

Cullen C, Webb A. Ocular manifestations of systemic diseases. Part 1: The dog. In: Gelatt KN, ed., Veterinary Ophthalmology, 5th ed.Ames, IA: Wiley-Blackwell, 2013, pp. 1897–1977.

Hendrix D. Diseases and surgery of the canine anterior uvea. In: Gelatt KN, ed., Veterinary Ophthalmology, 5th ed.Ames, IA: Wiley-Blackwell, 2013, pp. 1146–1198.

Martin C. Anterior uvea and anterior chamber. In: Ophthalmic Disease in Veterinary Medicine. London: Manson Publishing, 2010, pp 298–336.

Miller P. Uvea. In: Maggs DJ, Miller PE, Ofri R, Slatter's Fundamentals of Veterinary Ophthalmology, 5th ed. St. Louis, MO: Elsevier Saunders, 2013, pp. 220–246.

Author Ian P. Herring

Consulting Editor Paul E. Miller

Client Education Handout Available Online