Ch.59 Intraocular Surgery

Question 1

What % of horses with ERU lose vision or had the eye removed

Answer 1

28% lost vision
12% had eye removed
(15% euthanised)

Question 2

Prevelance of ERU in USA vs UK

Answer 2

USA 2-25%
UK 0.3%

Question 3

ERU is characterised by

Answer 3

Repeated episodes of intraoccqular inflammation

Question 4

The uveal tract is composed of what structures

Answer 4

Iris
Ciliary body
Choroid

Question 5

Breakdown of the blood aqueous barrier causes what

Answer 5

-Vascular dilation
-Increased vascular permeability
leading to
-increased levels of protein and cells within the aqueous vitreous humor

Question 6

What is the Tyndall effect

Answer 6

increased protein within humor scatters light aka aqueous flare

Hallmark of uveitis

Question 7

Primary inflammatory mediator in ERU

Answer 7

Prostaglandins
Leukotrienes

Question 8

Effect of prostaglandins in ERU

Answer 8

Hyperemaia
Hypotony
Constrict iris and ciliary muscles - miosis and pain

Question 9

What is posterior synechia and what causes it

Answer 9

Prolonged miosis and increased protein levels causes adhesions between posterior bridal epithelium and the anterior lens

Question 10

Effects of posterior synechia

Answer 10

Extensive synechia can obstruct the pupil causing blindness

Can block fluids behind iris causing anterior bowing - iris bombe

Secondary glaucoma

Question 11

Most frequent inciting cause of ERU

Answer 11

Leptospira interrogans