The Blind Eye

Question 1

What are some common causes of blindness?

Answer 1

Symblepharon 
Keratitis
Persistent pupillary membranes
Uveal problems 
Cataracts 
Glaucoma 
Fundic disease

Question 2

What is symblepharon?

Answer 2

Two layers stuck together:

Conjunctiva and cornea
Eyelid and cornea
Eyelid and conjunctiva

Question 3

What is a key cause of symblepharon in kittens/cats ?

What is the general pathogenesis?

Answer 3

FHV type I

Causes ulceration of the conjunctiva and cornea
- wounds stick together and create adhesions

(Uncommon)

Question 4

What type of keratitis is common in brachys?

Answer 4

Pigmentary keratopathy

• pigment on cornea
• occurs secondary to entropion, distichiasism, eurynlepharon

Question 5

What is euryblepharon?

Answer 5

Large palpebral fissure

Question 6

What is lagopthalmus?

Answer 6

inability to close eyelid completely

Question 7

How do you treat patients with pigmentary keratopathy due to brachycephalic ocular syndrome?

Answer 7

Surgical correction of euryblepharon (etc)

Question 8

What is the pupillary membrane

Answer 8

Embryologic membrane that should regress
Originates from iris colarette

BVs which emerge from middle part of iris and nourish lens during development

Question 9

What can PPMs cause?

Answer 9

Corneal and/or lens opacity

Question 10

What clinical signs are associated with uveitis?

Answer 10

FLARE - Tyndall effect

Hypopion +/ hyphaema
Synechia - adhesions between iris and cornea or lens

DECREASED IOP - can increase if chronic

Question 11

Why do you see reduced IOP in patients with acute uveitis?

Answer 11

Ciliary body doesn’t produce as much aqueous humour

Question 12

What is the uvea?

Answer 12

All the vascular tissue in the eye

• iris and ciliary body - anterior
• choroid - posterior

Question 13

What causes flare?

Answer 13

Increased proteins in the anterior chamber

Question 14

Does hypopion always indicate infection?

Answer 14

NO

Usually STERILE

Question 15

What is the difference between anterior and posterior synechia?

Answer 15

Anterior - iris adheres to cornea

Posterior - iris adheres to lens

Question 16

How can you differentiate between PPMs and synechia ?

Answer 16

PPM - originates from iris colarette (middle segment)

Synechia - comes from margin of iris

Question 17

What complications can occur due to uveitis?

Why?

Answer 17

Corneal oedema - damage to endothelium which usually pumps out fluid
Cataracts - poor nourishment to lens
Synechia
Retinal detachment - inflammation of choroid
Lens luxation in cats
Glaucoma - accumulation of inflammatory cells etc

Question 18

What causes uveal problems ?

Answer 18

• systemic hypertension
• infectious
• immune mediated
• neoplastic
• complicated ulcers

Question 19

What are some infectious causes of uveitis?

Answer 19

Viral - FeLV, FIV, FIP
Bacterial - pyo and others e.g. cystitis
Parasitic - Toxoplasma, Leishmania
Fungal- Cryptococcus (not common)

Question 20

What neoplasms can cause uveitis?

Answer 20

Lymphoma MOST COMMON

Metastatic adenocarcinoma

Question 21

What is reflex uveitis ?

Answer 21

CNV irritated causing epiphora and reflex cascade leading to uveitis

Question 22

What is the most common cause of uveal problems?

What is the suggested tx ?

Answer 22

Idiopathic

Immunosuppressive therapy

Question 23

When can you use steroids?

Answer 23

If corneal ulcer has been RULED OUT

Question 24

What opthalmic findings would you expect with systemic hypertension?

Answer 24

Intraocular haemorrhage
Bullous retinal detachment
Iris earl haemorrhages
Tortuosity of retinal vessels (don’t look as straight)

Question 25

What is a cataract?

Answer 25

Any opacity of the lens which impedes light transmission

Question 26

How are cataracts related to uveitis?

Answer 26

Can cause uveitis Can be a sequel to uveitis due to poor lens nourishment

Question 27

What is the difference between cataracts and nuclear sclerosis?

Answer 27

Nuclear sclerosis isn’t associated with visual defects - can still see through it on fundoscopy Aging change that generally does NOT cause blindness

Question 28

Which cataracts cause blindness?

Answer 28

Complete

Question 29

What are the causes of cataracts?

Answer 29

``` Inherited Congenital Traumatic Metabolic Nutritional PRA Senile ```

Question 30

How do traumatic cataracts tend to occur?

Answer 30

Blunt trauma (compression of eye) or penetrating trauma (FB or scratch)

Question 31

How can phacoclastic uveitis occur secondary to FB trauma? How is it treated?

Answer 31

FB opens up lens capsule leading to leakage of lens protein into the anterior chamber and expose it to the immune system. Difficult to control medically - Lens removal usually indicated - REFERRAL

Question 32

What causes metabolic cataracts?

Answer 32

DIABETES in DOGS (rare for cats)

Question 33

Describe the appearance of senile cataracts

Answer 33

Cortex (periphery) Wedge shaped Rarely progress to complete cataract

Question 34

What should you do to relieve pain in end stage glaucoma?

Answer 34

REMOVE EYE

Question 35

What are some key retinal diseases?

Answer 35

Retinal dysplasia PRA Retinal toxicity - high dose enrofloxacin in cats Acute retinal disease - SARDS, IMR

Question 36

What breed is typically affected by retinal dysplasia?

Answer 36

SPANIELS CKCS ESS Congenital

Question 37

What is PRA? What CS is it associated with

Answer 37

Progressive Retinal Atrophy Night blindness progress to day blindness Leads to cataract (end stage) Not painful

Question 38

What is associated with PRA on opthalmic examination?

Answer 38

Hyperreflective Tapetum - retinal thinning Vascular attenuation - retinal vessel thinning Late stage: cataracts

Question 39

What is retinal detachment? | What are the two types?

Answer 39

Neuro-retina detaches from retinal pigment epithelium INFLAMMATORY = BULLOUS DISINSERTIONAL = RHEGMATOGNOUS

Question 40

What causes bullous retinal detachment?

Answer 40

Retina is pushed by fluid

Question 41

What causes rhegmatogenous retinal detachment ?

Answer 41

Retina loses peripheral attachments

Question 42

What are the clinically significant optic nerve diseases?

Answer 42

Optic neuritis Optic nerve neoplasia

Question 43

What causes optic neuritis?

Answer 43

Meningoencephalitis of known origin / aetiology(MUO/A) Infectious diseases - Distemper - Ehrlichia - Cryptococcus

Question 44

What is the most common neoplasia of the optic nerve?

Answer 44

MENINGIOMA

Question 45

How can you identify optic neuritis

Answer 45

Hyperaemia of the papilla Vascular congestion Peri papillary haemorrhages