Ophthalmic emergencies Flashcards
List 6 ocular emergencies
traumatic globe prolapse
Retrobulbar abscess
Acute glaucoma
Anterior lens luxation
Corneal emergencies
Sudden onset blindness
describe a globe prolapse
globe is acutely displaced forwards, beyond the plane of the eyelids
describe exophthalmos
a degree of forwards displacement of the globe with the eyelids remaining in a normal anatomical position
Describe how globe prolase occurs
immediate oedema of the conjunctiva and orbital soft tissue leads to exopthalmos
eyelid spasm further exacerbates the issue and blocks the venous drainage
leading to more swelling and eventual prolapse
Are cats likely to have globe prolapses
no- they have deeper orbits and therefore deeper protection
List the positive indicators to attempt replacement in grobe prolapse cases
brachycephalic breeds
positive PLR
eye attempting to move
List the 2 treatment options for globe prolapse
replacement or enucleation
what do we use to clean the eye for surgery
povidine- iodine solution
after replacing the prolapsed globe, what can you do to ensure the eye doesn’t reprolapse
temporary tarsorraphy - suture the eyelids together
after replacing a globe prolapse, what needs to be done in terms of aftercare
systemic antibiotics (chloramphenicol) and NSAIDs
buster collars
re-evaluate after 10-15 days
after globe prolapse occurs, do the animals normally retain vision in that eye
No
List the clinical signs of a retrobulbar abscess
acute onset
unilateral
exopthalmos
painful
third eyelid protrusion
ocular discharge
pyrexia
lethargy
why are retrobulbar abscesses an ocular emergency
pressure on the optic nerve can cause temporary blindness that if not treated can turn into permanent blindness
how can we medically manage retrobulbar abscesses
systemic NSAIDs + antibiotics (amoxiclav +/- metronidazole)
IVFT
topical lubricants
List the clinical signs of acute glaucoma
ocular pain
head shy
yelping
dull
vision loss
change in appearance
what is the triad of ocular pain signs
blepharospasm
increased lacrimation
photophobia
what can we see in the eye in acute glaucoma cases
corneal oedema
episcleral congestion
and/or fixed/dilated pupils
how do we diagnose acute glaucoma
tonometry
normal IOP in dogs and cats
10-25 mmHg
List some medications to reduce IOP
prostaglandin analogues (latanoprost)
carbonic anhydrase inhibators (nrinzolamide, dorzolamide)
beta-blockers
when can we give IV mannitol for glaucoma
if they are not responding to any drops
Describe acute glaucoma medical treatment
reduce IOP with prostaglandin analogues, carbonic anhydrase inhibitors or beta-blockers
analgesia
referral ASAP
if we lose one eye to acute glaucoma what do we need to make sure to do
investigate the second eye for an underlying cause
what breeds are predisposed to anterior lens luxation
terriers
what happens when the lens luxates anteriorly
it can block the drainage of the eye
List the clinical signs of anterior lens luxation
acutely painful
glaucoma
corneal oedema
what can sometimes differentiate anterior lens luxation from primary glaucoma
the presence of the lens outline in the anterior chamber
Describe how to treat anterior lens luxation
referral for surgery- remove or push lens backwards
analgesia
IOP reducing medication - need to use carbonic anhdyrase inhibitors or betablockers as prostaglandin analogues won’t be helpful
why do prostaglandin analogues not help in anterior lens luxation cases
because the lens is blocking the draining, you therefore can’t increase the draining
what is an aphakic crescent in the pupill
a small crescent that indicates that the lens has subluxated
List 4 corneal emergencies
chemical injury
FB
Melting ulcer
severe lacerations
Describe how to treat chemical injuries to the eye
immediate irrigation of the ocular surface using flush/water
test pH of conjunctiva
early specialist advice
if there are large corneal foreign bodies, what should we do
provide analgesia and a buster collar and refer immediately
List the clinical signs of a melting corneal ulcer
acute
painful
gloopy discharge
corneal oedema
anterior uveitis
List 8 causes of sudden onset blindness
Acute glaucoma
Acute uveitis
Intraocular haemorrhage
Retinal detachment
Optic neuritis
SARD (Sudden Acquired Retinal Degeneration)
Toxicity
Intracranial lesion
