Uveal disease: what can go wrong with the uvea in dogs and cats? (Proceedings)


Diseases of the uvea

Diseases of the Uvea

     • Developmental

     • Degenerative

     • Infectious

     • Immune –mediated

     • Idiopathic

     • Inflammatory

     • Metabolic/ Nutritional

     • Toxic

     • Traumatic

     • Neoplastic

Developmental diseases

     • Incomplete Development

     • Maldevelopment

     • Incomplete regression of embryonal tissues

Color variants

     • Subalbinism

          o Dilution not absence of pigment

          o Blue eyes- lack pigment in stroma but overlies pigmented neuroectoderm

          o True Albino- pink or red iris due to complete lack of pigment

     • Heterochromia Iridis

          o Multiple colors within one iris or between eyes

          o Component of merling gene

          o Can accompany other iridal abnormalities

Persistent pupillary membranes

     • Pupillary membranes should atrophy by 6 weeks of age

     • PPMs arise from the collarette region of the iris

     • Iris-to-iris, iris-to-cornea, iris-to-lens

     • Basenji: heritable PPMs

     • Corgi, Chow, Mastiff: familial PPMs

Aplasia/ hypoplasia

     • Aniridia: total absence of iris tissue

     • Iris Hypoplasia

          o Notch Coloboma: affects the pupil margin

          o Pseudopolycoria: one or more holes in iris body

          o Iridodiastasis: defect in iris base

Iris hypoplasia

Pupillary abnormalities

     • Polycoria: one or more extra pupillary opening

          o Each opening has its own functional sphincter and dilator muscles

          o Rare

     • Corectopia: abnormal position of pupil

     • Microcoria: congenital miosis due to lack of dilator muscle

Congenital uveal cysts

     • Originate from persistence of space between the two layers of neuroectoderm or primary optic vesicle

     • Fluid accumulates between these epithelial layers

     • From pars plicata of the ciliary body or pupillary margin of the iris

Anterior segment dysgenesis

     • Doberman, Saint Bernard

     • Autosomal recessive trait

     • Primary defect in formation of the neuroectodermal optic cup causing abnormal induction of mesenchyma

     • Congenital blindness

     • Clinically: microphthalmia, opaque corneas, absent anterior chamber, undifferentiated iris and ciliary body, absent or rudimentary lens, hyaloid artery remnants, retinal dysplasia, retinal separation

Collie eye anomaly

     • Patchy to diffuse choroidal hypoplasia is the hallmark of CEA

     • Inherited as an autosomal recessive trait

     • Results from failure of induction by a defective RPE (abnormal pigmentation)

     • Similar syndrome in Aussies, Border Collies, Shelties, and other color dilute breeds

Collie eye anomaly

     • Lesions are dorsotemporal, bilateral, asymmetrical

     • Generally at the junction between tapetal and nontapetal fundi

     • Fewer, wider, and abnormal arrangement of choroidal vessels, increased sclera is visualized

Degenerative diseases

     • Senile Iris Atrophy

          o Progressive thinning of iris stroma

     • Secondary Iris Atrophy

     • Essential Iris Atrophy


     • Massa KL, et al. Causes of Uveitis in dogs: 102 cases (1989-2000). VO 5(2); 2002: 93-98

          o Infectious: 17.6%

          o Immune-mediated/ Idiopathic: 57.8%

          o Neoplasia: 24.5%

     • Clinical Signs

          o Aqueous flare: 86%

          o Corneal Edema: 61%

          o Keratic Precipitates: 11%

          o Systemic Signs: 56%

Canine infectious uveitis

     • Algal

          o Prototheca

     • Fungal

          o Blastomyces

          o Cryptococcus

          o Coccidioides

          o Histoplasma

     • Viral

          o Adenovirus

          o Distemper

          o Herpes

          o Rabies

     • Parasitic

          o Diptera (Ophthalmomyiasis interna posterior)

          o Dirofilaria (Ocular filariasis)

          o OLMs (Toxocara, Balisascaris)

     • Protozoal

          o Leishmania

          o Toxoplasma

          o Rickettsia

          o Ehrlichia

     • Bacterial

          o Brucella canis

          o Lymes disease

          o Leptospirosis

          o Septicemia

Feline infectious uveitis

     • FIV

     • FeLV

     • FIP

     • Bartonella

     • Toxoplasma gondii

     • Cryptococcus

     • Histoplasma

     • Coccidiosis

     • Candida albicans

Uveodermatologic syndrome

     • Vogt-Koyanagi-Harada in humans

     • Young adults (mean age 2.8 years)

     • Akita, Samoyed, Husky, Sheltie

Uveodermatologic syndrome

     • Ocular signs can precede dermatologic signs

     • Ocular clinical signs

          o Bilateral anterior or panuveitis, uveal depigmentation, retinal separation, blindness, cataract formation, iris bombe, glaucoma

     • Dermatologic clinical signs

          o Vitiligo of eyelids, nasal planum, lips, foot pads

          o Poliosis

Uveodermatologic syndrome

     • Immune mediated destruction of ocular and dermal melanocytes

     • Histopathology reveals interface dermatitis with primarily a lichenoid pattern

          o Large histiocytic cells, plasma cells, and small mononuclear cells

     • Treatment

          o Topical and systemic corticosteroids

          o Systemic immunosuppressives (Immuran)

Lipid aqueous

     • Often unilateral, sudden onset

     • Skim milk appearance

     • Systemic hyperlipidemia

          o Disruption of BAB

          o DM

          o Hypothyroidism

          o Hepatic disease

          o Pancreatitis

          o Breed- Schnauzer

Lens-induced uveitis

     • Pathophysiology

          o Weakly antigenic alpha-crystallin is normally released from the lens capsule inducing a T-cell tolerance to low antigen levels

          o Sudden release of large amounts of lens cellular and membrane protein exceeds normal tolerance and leads to LIU

Lens-induced uveitis

     • Phacolytic

          o Lens protein leakage

          o Decreased release of antigen

          o Phagocytosis of protein by macrophages

          o No release of cytokines and IL-1

     • Phacoclastic

          o Lens protein and membrane proteins are presented

          o T- cell response is activated by MHC-II presenting cells

          o Release of cytokines and IL-1

          o Chemotaxis of neutrophils

Pigmentary uveitis

     • Golden Retrievers

     • Bilateral disease

     • Clinical signs: pigment dispersion in anterior chamber, dark thickened iris, pigmented anterior lens capsule, posterior synechia, cataract formation, glaucoma

     • Uveal cysts may be associated

Traumatic hyphema

     • Occurs when uveal or retinal vessels are torn or disrupted

     • Most commonly due to head trauma

     • Concurrent injuries

          o Orbital fractures

          o Eyelid or facial trauma

          o Retinal detachments

Traumatic hyphema

     • Additional diagnostics

          o Physical examination

          o Ocular ultrasound

          o Skull radiographs

     • Treatment

          o Topical and systemic corticosteroids

          o Atropine???

          o TPA???

     • Resorption can occur in 7 to 21 days, consolidation of blood should be observed in 8 days

Primary uveal neoplasia

     • Benign

          o Melanocytoma

          o CB adenoma

          o Cavernous hemangioma

          o Ciliary body hemangioma

          o Medulloepithelioma

     • Malignant

          o Melanoma

          o Melanocarcinoma

          o CB adenocarcinoma

          o LSA

          o Feline Sarcoma

          o Iridal HAS

          o Iridal Leiomyosarcoma

Secondary uveal neoplasia

     • Hematogenous route of metastasis

     • Bilateral is more common

     • LSA and HSA is most common

     • Cutaneous or oral melanoma, SCC

Canine uveal neoplasia

     • Melanocytic neoplasms (melanomas)

          o Most common primary intraocular neoplasm in the dog

          o Locally invasive, Low incidence of metastasis (4%)

          o Arise in anterior uvea

          o Iris and Ciliary body

          o Older dogs (8-10 years)

Canine uveal neoplasia

     • Clinical Signs of Melanoma

          o Darkly pigmented nodular mass

          o Diffuse infiltration is less common in the dog

          o Extending through the pupil

          o Displacing the iris anteriorly

          o Dyscoria

          o Free floating pigment in anterior chamber

Canine uveal neoplasia

     • Ciliary Body Adenoma/ Adenocarcinoma

          o 2nd most common

          o Low rate of metastasis, locally extensive

          o Originate from non-pigmented or pigmented epithelium

     • Medullepithelioma

          o Young dogs

          o Benign, low metastasis, local extension

          o Originate from neuroectoderm cells

Feline uveal neoplasia

     • Melanoma

          o Most common primary tumor in the cat

          o Hyperpigmentation of iris, irregular texture or iris, multifocal to diffuse appearance, infiltrate ICA, pigmented floaters in anterior chamber, increased IOP

          o Malignant transformation

          o Pulmonary and hepatic metastasis

Feline uveal neoplasia

     • Dubelzieg VO 1(1) 1998 p25-29.

          o Retrospective study of 32 cats with histologically confirmed diffuse uveal melanoma

          o Affected cats did have a decreased survival rate

          o Cats with extensive disease had the lowest survival rates

Feline uveal neoplasia

     • Trauma- associated sarcoma

          o 2nd most common

          o Highly malignant

          o Risk factors include trauma to lens, chronic uveitis, intraocular surgery???, CBA

          o Early exenteration recommended

Feline uveal neoplasia

     • Lymphosarcoma

          o Pink to white mass in the anterior chamber, "D" shaped pupil

          o Uveitis

          o Secondary glaucoma

          o FeLV-antigen positive cats

          o Aqueocentesis or BM aspirate can be diagnostic

Differentials for Uveal Neoplasia

     • Benign uveal proliferations

          o Ectropion uvea, Rubeosis iridis, Iris hyperpigmentation, Nevi/freckles

     • Uveal cysts

     • Uveal granulomas

     • Extraocular tumor with intraocular extension

     • Perforating ocular trauma with uveal prolapse


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