Ocular pathology 2 Flashcards
What is the uvea?
vascular structure of the eye
Components of the uvea
- iris
- ciliary body
- choroid
What is anterior uveitis?
inflammation of the iris &/ or ciliary body
What is posterior uveitis?
inflammation of the choroid
What are some effect that uveitis can cause to the globe?
- Corneal edema
- keratic precipitation
- synechiae
- cataract
- retinal detachment
How does Uveitis cause corneal edema?
cytokine-induced permeability of the vasculature in the peripheral limbic vessels
How does uveitis cause keratic precipitation in the cornea?
aggregates of cells & fibrin on the posterior surface of the cornea
How does uveitis cause cataracts at lens?
alteration of flow & composition of the aqueous humor
What does uveitis usually cause the formation of?
pre-iridal fibrovascular membrane (granulation tissue
When are angiogenic factors released in uvea?
- chronic uveitis
- hypoxemia (retinal detachment)
- neoplasia
What is anterior synechia?
fibrin within the anterior chamber coating the iris, leading to adherence of the iris to cornea
What is posterior synechia?
fibrin within th anterior chamber coating the iris, leading to adherence of the iris to the lens
How does iris bombe occur?
- complete circumferential posterior synechia
- cause disruption of flow in the aqueous from posterior to anterior chamber (pupillary block)
- increase in pressure
- causes anterior bowing of the iris
What is the most common cause of glaucoma, cataracts, & blindness in horses?
equine recurrent uveitis
Characteristics of equine recurrent uveitis
- syndrome
- waxing & waning uveitis
- starts off unilateral and ends up being bilateral
- presentation: corneal edema, aqueous flare, vitreal protein
- lymphocytes in ciliary epithelium & iris
- amyloid-like deposition on ciliary epithelium
What does chronic equine recurrent uveitis present as?
-cataract
- retinal detachment
- lens luxation
- glaucoma
-blindness
Pathogenesis of equine recurrent uveitis
- unknown
- considered multifactoral: autoimmune & infectious agent (altering normal immunologically privileged state of the eye
What is the most common uveitis in cats?
idiopathic lymphoplasmacytic uveitis
Presentation of Feline lymphoplasmacytic uveitis?
- corneal edema
- vascularization
- keratic precipitation
- secondary glaucoma is common
- can be unilateral or bilateral
