The blind eye

Question 1

What are the causes of blindness?

Answer 1

1. symblepharon
2. keratitis
3. uveal disease
4. cataracts
5. glaucoma?
6. posterior segment disease (vitreous, retina)

Question 2

How can glaucomas cause blindness?

Answer 2

high intraocular pressure
neurodegenrative dz
progressive and ultimately kleads to blindness

Question 3

What is symblepharon?

Answer 3

condition where there is adhesion of conjunctival tissue to another conjunctival surface or the cornea

mostly seen in kittens and feline herpesvirus type 1

Question 4

What is pigmentary keratophathy?

Answer 4

pigment on the cornea
secondary to entropion, trichiasis, euryblepharon

common in brachycephalic

Question 5

What are the clinical signs of uveitis?

Answer 5

flare on tyndall effect
hypopyon (WBC)
hyphema (blood)
synechia (anterior, posterior)
decreased IOP unless chronic (increased)

Question 6

What are potential causes for hyphema?

Answer 6

don’t assume trauma unless injury observed

lung worm dz
systemic hypertension
immune-mediated thrombocytopenia, coagulopathy, intraocular neoplasia
infectious disease: ehrlichia, leishmaniasis

Question 7

What are the 2 types of sequelae?

Answer 7

anterior synechia: corneal perforation causing adhesion of the iris to the cornea

posterior synechia: adhesion of iris to the lens

Question 8

What is persistent pupillary membranes PPMs?

Answer 8

developmental abnormalities that should have regressed
originate strands from the iris collarete
can cause corneal or lens opacity

Question 9

What are potential complications of uveitis?

Answer 9

• corneal oedema
• cataracts
• synechiae
• pre-iridal fibrovascular membranes
• retinal detachment
• lens luxation
• glaucoma

Question 10

What are the causes of uveal disease?

Answer 10

• systemic hypertension
• infectious (viral, parasitic, fungal, bacterial)
• immune-mediated
• neoplastic
• complicated ulcers/reflex uveitis

Question 11

What are primary and secondary causes for uveal disease?

Answer 11

primary: opthalmic causes (complicated ulcer, FB, etc.)

secondary: systemic causes (infl., hypertension, idiopathic, etc.)

Question 12

How do we treat uveal disease?

Answer 12

TREAT CAUSE
start systemic anti-inflammatories if possible
topical anti-inflammatory tx

Question 13

What are the systemic non-steroidals and steroids we can give as systemic anti-inflammatory for uveal dz?

Answer 13

non-sterioidal” carprofen, meloxicam
steroid: prednisolone

Question 14

What are the types of topical anti-inflammatory tx we give for uveal dz?

Answer 14

steroid eye drops: prednisolone acetate, dexamethasone phosphate
cycloplegics: atropine/cyclopentolate
(stop spasms of the ciliary body)

Question 15

What are the possible ophtalmic findings of animals with hypertension?

Answer 15

intraocular haemorrhage
bullous retinal detatchment
iridal haemorrhages
tortuosity of retinal vessels

Question 16

What is equine recurrent uveitis (ERU) ?

Answer 16

heterogenous disease
nonspecific immune mediated
leading cause of blindness in horses
peak initial uveitis episode at 4-6y/o
warmbloods, draft, european

Question 17

What is the signs of classic ERU?

Answer 17

most common type
active inflammatory episodes followed by periods with minimal ocular signs

increasingly severe episodes of uveitis and progress to chronic signs

Question 18

What are acute classic ERU signs?

Answer 18

miosis
iris hyperaemia/swelling
ocular pain
conjunctival hyperaemia
corneal oedema
fibrin in anterior chamber

Question 19

What are the chronic signs of classic ERU?

Answer 19

atrophy
granular iridica
fibrosis iris
ICA
hyperpigmentation iris

Question 20

What are the complications of classic ERU?

Answer 20

cataract
posterior synechia
glaucoma
phthisis bulbi

Question 21

What are the clinical signs of insidious ERU?

Answer 21

minimal signs of ocular discomfort
low-grade immune response that continues and slowly progresses to chronic clinical signs ERU

appaloosa, draft breed
difficult to dx until severe chronic signs

Question 22

What are the clinical signs of chronic insidious ERU?

Answer 22

ICA fibrosis
iris fibrosis
cataract formation
conjunctival hyperaemia
iris hyper pigmentation
granula iridica atrophy
synechia formation

Question 23

What are the clinical signs of posterior ERU?

Answer 23

subtle anterior uveitis (miosis)
vitreal opacities (pond-like reflexion of the vitreous)
retinal inflammation
retinal detachment or degeneration

Question 24

What is the first and second aim when tx ERU?

Answer 24

first: preserve vision
second: reduce and control ocular inflammation to limit permanent damage to the eye

Question 25

What are the medical tx for acute ERU cases?

Answer 25

topical steroids/NSAID atropine systemic anti-infl.

Question 26

What are the medical tx for severe chronic ERU cases?

Answer 26

subconjunctival or intravitreal injection steroids

Question 27

What are the 3 possible surgical tx for ERU?

Answer 27

suprachoroidal cyclosporine implants pars plana vitrectomy (clears media/remove membranes) enucleation

Question 28

What are the 2 ways cataracts can cause uveitis?

Answer 28

phacolytic: leaky lens (lens protein diffuse through intact lens capsule with chronic cataracts) phacoclastic: ruptured lens (protein gets into eye via rupture of lens capsule)

Question 29

What are the 2 ways chronic uveitis can cause cataracts?

Answer 29

due to poor nourishment of the lens altered chemistry of the aqueous humour

Question 30

What is the difference between direct illumination and retroillumination of cataracts?

Answer 30

direct illumination: cataract will look fully white retroillumination: shadow/dark from behind the opacity

Question 31

What type of cataracts interfere with sight and cause blindness?

Answer 31

incipient, immature and mature interfere with sight mature only will cause blindness

Question 32

What are the 7 causes for cataracts?

Answer 32

inherited congenital traumatic metabolic nutritional progressive retinal atrophy senile

Question 33

Where do congenital cataracts form?

Answer 33

always nuclear

Question 34

What are causes of traumatic cataracts?

Answer 34

FB cat scratches

Question 35

What type of uveitis can be induced by traumatic cataracts?

Answer 35

phacoclastic uveitis tear can cause a FB reaction = need to remove the lens material w/ cataract surgery to stop chronic uveitis

Question 36

What causes metabolic cataracts?

Answer 36

diabetic cataractogenesis glucose is small enough to difuse into lens capsule from aqueous humour its made into sorbitol, too big to leave lens draws water in w/ osmosis, lens can eventually rupture

Question 37

What are nutritional causes for cataracts?

Answer 37

uncommon now puppies and kittens fed inappropriate milk replacementrs, deficiency of essential amino acids

Question 38

How does progressive retinal atrophy cause cataracts?

Answer 38

secondary to retinal degeneration degenerating retina releases toxins which cause cataracts

Question 39

What is often affected with senile cataracts?

Answer 39

the cortex is generally affected wedge shaped if small might not occlude vision

Question 40

What are vitreal diseases causing blindness?

Answer 40

persistent hyaloid artery and primary vitreous cataracts +/-

Question 41

What are retinal diseases that can cause blindness?

Answer 41

retinal dysplasia progressive retinal atrophy retinal toxicity: high dose enrofloxacin in cats acute retinal diseases (Sudden acquired retinal degeneration syndrome and immune-mediated retinopathy)

Question 42

What are the 3 main types of retinal dyplasia and what breeds are prone?

Answer 42

retinal folds geographic retinal detachment (severe) CKCS, ESS

Question 43

What is progressive retinal atrophy PRA?

Answer 43

inherited degenerative disease of the retina causing night blindness and eventually day blindness can lead to cataracts but can't get sx to tx it

Question 44

What can inidcate progressive retinal atrophy in an ophtalmic examination?

Answer 44

clinical hx breed hyperreflective tapetum (thinning of retina) vascular attenuation (thinning retinal vessels) late stage: cataracts

Question 45

What drugs are toxic to retinas in cats?

Answer 45

high dose enrofloxacin even at current recommended doses can also cause neuro signs ** all fluoroquinolones to be used with caution but no retinal toxicity is reported w/ pradofloxacin!

Question 46

How can we diagnose sudden acquired retinal degeneration syndrome SARDS?

Answer 46

acute/subacute vision loss PLR may or may not be present ophtalmic exam unremarkable diagnostic test: electroretinography!! (shows there is no response in retina)

Question 47

What are the 2 types of retinal detachment?

Answer 47

inflammatory: retina pushed by fluid (bullous, seagull shape) disindertional: retina loses peripheral attachments (rhegmatogenous)

Question 48

What are the causes for optic neuritis?

Answer 48

meningoencephalitis of unknown origin/aetiology (MUOA) infectious dz: distemper, ehrlichia, crypto,...

Question 49

What is the most common neoplasia of the optic nerve?

Answer 49

meningioma

Question 50

What are the signs of optic neuritis?

Answer 50

hyperaemia of the papilla vascular congestion peripapillary hemorrhages

Question 51

What is Collie Eye Anomaly (CEA)?

Answer 51

combination of choroidal hypoplasia and optic nerve head coloboma can develop retinal detachment, hyphema, vitreal haemorrhage

Question 52

What are the causes of blindness?

Answer 52

glaucoma: high intraocular pressure eyelid abnormalities: symblepharon corneal abnormalities: pigmentation uveal disease: hypopyon, hyphaema catarcats retinal and optic nerve diseases