Ophthalmology - Uvea Flashcards
What is persistent pupillary membrane?
- incomplete absorption of embryonic vascular tissue and mesenchymal strands
- originate in iris collarette
What is uveitis?
inflammation of the uvea and breakdown of the blood ocular barrier
What is included in anterior uveitis?
iris and ciliary body
What is included in posterior uveitis?
choroid
What is included in endophthalmitis?
entire uvea and intraocular contents
What is included in panophthalmitis?
all ocular and intraocular structures
What are the non-specific clinical signs associated with uveitis?
epiphora blepharospasm photophobia red eye (ciliary flush or episcleral injection) corneal edema
What are the specific signs associated with uveitis?
- miosis
- aqueous flare
- hyphema, hypopyon
- keratic precipitates
- swollen/thickened iris
- hyperemic iris
- decreased IOP
Describe miosis as a sign of uveitis
- due to inflammation driven by prostaglandins
- causes pain from ciliary body spasm
- causes iris sphincter muscle contraction
Describe aqueous flare
- increased turbidity of aqueous humor due to breakdown of the blood-aqueous barrier with inflammation
- protein and cells in anterior chamber causing light scatter
What are keratic precipitates?
inflammatory cells +/- fibrin adhered to the corneal endothelium
What causes decreased IOP in uveitis?
inflammation driven by prostaglandins
- decreased aqueous humor production
- increased uveoscleral outflow
What are the clinical signs associated with chronic uveitis?
dyscoria
posterior synechia
peripheral anterior synechia
iris hyperpigmentation
What are the long term sequels of chronic uveitis?
- cataract
- secondary lens luxation
- secondary glaucoma
- retinal detachment
- phthisis bulbi
How is uveitis generally treated?
- topical corticosteroids +/- topical NSAIDs
- systemic corticosteroids or systemic NSAIDs
- topical atropine
- +/- systemic antimicrobials
Which topical corticosteroids are used to treat uveitis?
Prednisone Acetate
Dexamethasone
Which topical NSAIDs are used to treat uveitis?
Flurbiprofen
Diclofenac
Which systemic corticosteroids are used to treat uveitis?
Prednisone
Prednisolone in cats
When should systemic corticosteroids be used?
if vision loss is imminent due to inflammation or secondary glaucoma
Which systemic NSAIDs are used to treat uveitis?
Carprofen or Meloxicam in dogs
Meloxicam or Robenacoxib in cats
What are the benefits of using atropine to treat uveitis?
- reduces pain of ciliary body spasm
- reduces risk of posterior synechia
- stabilizes blood ocular barrier
What are the clinical signs associated with uveal tumors?
- uveitis +/- hyphema
- iris or ciliary body mass
- iris displacement
- secondary glaucoma
What are the most common primary uveal tumor in the dog?
Describe the features
melanoma/melanocytoma
- very low metastatic rate
What are the most common primary uveal tumor in the cat?
Describe the features
Feline diffuse iris melanoma
- metastasis common
What is the most common secondary uveal tumor?
lymphosarcoma
What is cycloplegia?
paralysis of the ciliary body
