Uvea

Question 1

Parts of the uvea

Answer 1

• Iris - forms pupil
• Ciliary body
– Makes aqueous humour • Choroid
– Supplies retina

Question 2

Uveal cysts

Answer 2

• Posterior iris or ciliary body in origin

Question 3

Persistent pupillary membranes

Answer 3

When the iris/vasculature of the eye early on, they don’t rarify or degenerate as they should leaving you remnants, e.g. persistent pupillary membranes
Strand starting at the iris & ending at the iris, etc.
Iris to cornea or iris to lens - don’t breed
• Iris to iris, iris to cornea, iris to lens

Question 4

Iris coloboma

Answer 4

Congenital hole in the iris.

Question 5

Iris atrophy

Answer 5

Common thing you’ll see in a small dog. Can be quite mild. Nothing we can do. Old age condition. Don’t go in bright lights. May squint, tear more.

Question 6

Uveitis

Answer 6

Inflammation of uveal tract. Can get leakage of blood vessels because they are more permeable. Prostaglandins released. Inflammatory products will impact on each other. Nitrous oxide, TGF2beta, that will compound the problem leading to uveitis. Sometimes it can be mostly in the anterior or posterior uveitis, but all uveitis will always be to some degree a panuveitis. Will also have an inflammation of the scleral tissue- inflammation of all the tuniques of the eye. Endopthalmitis.

Question 7

Uveitis - clinical sigsn

Answer 7

Pain
Prolapse of your third eyelid
Photophobia
Red eye (bleeding, dilation etc)
Corneal edema, or aqueous flair(protein leaked into the aqueous so that it is turbid/plasmoid aqueous).  
Miosis
Aqueous flare
Vitreal flare
Retinal lesions

Question 8

Uveitis - causes

Answer 8

• Infectious
• Immune-mediated
• Breed related
• Trauma
• Neoplasia
• Idiopathic

Question 9

Uveitis - diagnosis

Answer 9

• Clinical signs
• Low intraocular pressures • Blood tests
• Chest radiographs
• abdominal ultrasound
• Additional tests – Serum titers
– Biopsy

Question 10

Uveitis - Treatment

Answer 10

• Treat underlying cause
• Anti-inflammatory therapy (if you don’t you may lose the eye)
– Topical (strongest Prednisolone acetate 1%, dex second)
– Systemic
• Cycloplegia

Question 11

Uveitis sequelae

Answer 11

• Cataract
• Posterior synechiae • Glaucoma
• Lens luxation
• Retinal detachment

Question 12

Uveitis neoplasia - melanoma

Answer 12

Most common tumour of the uvea. It’s usually benign, (dog), most likely in the iris or the ciliary body, and if it’s caught early enough you can laser it with a diode laser. If you catch it too late, you do need to enucleate.

Question 13

Uvea - adenoma/carcinoma

Answer 13

Adenoma>carcinoma
 – +/- pigment
– Histopathology
– Resection (if they are small enough, but they can hide behind the iris)
– Diode laser 
– Enucleation

Question 14

Uvea - lymphoma

Answer 14

Usually secondary, so does lower your survival rate. When they start on chemo, it does respond.