Ophth - cats Flashcards
Why do cats have vertical slit pupils?
Allow wider dilation at night
What is the field of view of cats eyes?
200 degrees
Binocular - 140 degrees
What can cause exophthalmos in cats?
Breed disposition
Exposure keratitis
Orbital space occupying lesion
Orbital neoplasia
What is proptosis?
Eyeball popped out of socket
What can cause proptosis in cats?
Brachy skulls
Trauma
What is the prognosis for proptosis? Why?
Very guarded - Uveitis, exposure keratitis
When do kittens eyelids open?
At 10-14 days of age
What is eyelid agenesis?
Part of upper eyelid missing
What signalment is entropion common in in cats?
Older cats or entire toms - thicker skin, chunky cheeks
What can cause entropion in cats?
Weight loss
What is a sign of chronic entropion?
Corneal vascularisation after conjunctivitis
What surgical technique corrects entropion?
Hotz-celsus technique
What is a normal shirmer tear test for cats?
18mm/min - but more inconsistant
Abnormal under 9mm/min accompanying clinical signs of KCS
What can cause cats to get dry eye? What is different to dogs?
Iatrogenic - atropine
Chronic blepharoconjunctivitis - FHV-1
NOT immune mediated like KCS in dogs
What causes infectious conjunctivitis commonly in cats?
Chlamydophila felis
FHV-1
Mycoplasma felis
What clinical sign differentiates chlamydia felis from other infectious diseases affecting the eye?
Chemosis - oedema in the conjunctiva
How do you treat chlamydia in cats?
Doxycycline for 4 weeks
What is a primary cause of corneal ulceration in cats?
FHV-1
What are secondary causes of corneal ulceration?
Corneal dryness
Trauma from entropion
What breeds are predisposed to sequestrum?
Persian
Bermese
What is a sequestrum?
Black corneal plaque with vascularisation, pain
What causes sequestrum?
Chronic corneal irritation
Dry eye - more exposed globe
How are sequestrum on the eye treated?
Keratectomy
When is feline herpes virus primary exposure?
8-12 weeks
Then develop latency and carrier status
What are the clinical signs of FHV-1 in kittens?
Conjunctivitis, closed lids fusing, symblepharon
What clinical sign can you use to diagnose FHV-1?
Dendritic ulcers - corneal epithelial ulceration
What is stromal keratitis?
Immune mediated inflammatory reaction causing blood vessel to emerge from the limbus across hte stroma
How do you diagnose keratoconjunctivitis due to FHV-1?
PCR - but may be negative in chronic cases, prone to false negatives
How can you treat keratoconjunctivitis due to FHV-1?
Antivirals - famciclovir
What must you not do to corneal ulcers in cats?
DO NOT DO grid keratotomy - causes sequestrum in cats, fine in dogs
How do you treat keratoconjunctivitis due to FHV-1?
Debride corneal ulcers
Topical NSAIDs
Antimicrobials if secondary infections
What is eosinophilic keratitis in cats?
Pinkish plaques on cornea - proliferative immune mediated
condition
What is the diagnosis for eosinophilic keratitis?
Cytology
What is the treatment for eosinophilic keratitis?
Topical steroids
What can cause uveal pigmentation seen in cats? Where is it seen most commonly
Melanoma - on the anterior uvea
What are the features of a uveal melanoma?
Primary malignant
Locally invasive
Highly metastatic - can be 3 years after enucleation
What is the most common primary intraocular tumour in cats?
Feline diffuse iris melanoma
How can you tell if a melanoma in a cats eye is malignant or benign?
Dark black rather than brown
Elevated from iris surface
Abnormal pupil shape
What is anterior uveitis linked to in cats?
Severe systemic disease
What can cause anterior uveitis?
Idiopathic lymphoplasmocytic
FIP/FCoV
FeLV
Trauma
What are the clinical signs of acute anterior uveitis?
Corneal oedema
Aqueous flare
Miosis
Iris colour change
What are the clinical signs of chronic uveitis?
Synechia
Cateract
Lens subluxation
Secondary glaucoma
What does a normal feline fundus look like?
Yellow-green tapetum
Non-myelinated circular optic nerve
3 pairs of blood vessels
Area centralis - blue oval
What condition can cause serous retinal exudate, haemorrhages and oedema?
Hypertensive retinopathy - high blood pressure
Today smoking is going to save lives
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