Opthal

Question 1

How does Iritis/Anterior Uveitis usually present?

Answer 1

• Uni/bilateral red eye
• Painful with photophobia
• Blurred but not reduced vision
• Scleral injection
• May have synechiae from previous inflammatory episodes, causes irregular pupil
• If inflammation bad enough may have hypopyon

Question 2

What are the causes of anterior uveitis?

Answer 2

Infections- Herpes, cytomegalovirus, covid 19, syphilis, toxoplasomosis

Inflammatory Conditions-HLA B27, ank spond, RA, SLE, kawasakis disease, sarcoid

Drug hypersensitivity- MABs such as Ipilimumab for melanoma, bisphosphonates, ciprofloxacin etc

Post traumatic inflammation and sympathetic ophthalmia

Question 3

How does a 3rd cranial nerve palsy present?

Answer 3

Dilated pupil (mydriasis)
Turned down and out
Ptosis

Question 4

What are the differentials for sudden unilateral painless loss of vision?

Answer 4

CRAO
- AF, ICA plaque, pale retina
- “cherry red spot”
- RF’s embolic, thrombotic, trauma and sickle cell

CRVO
- blood and thunder retina, HTN, diabetes

Retinal detachment
- age, myopia, may only have partial loss of vision, corrugated retina

Retinal haemorrhage
- HTN, diabetes, high chol

Vitreous haemorrhage
- trauma, obscured retina

Posterior Vitreous Detachment

Other
- Optic neuritis (although often painful)
- Giant cell arteritis (often temporal pain but not eye pain)
- Posterior circulation stroke and internal carotid/vertebral artery dissection
- Anterior ischaemic optic neuropathy
- PRES/Pre-eclampsia
- Functional
- Migraine (usually painful)

Question 5

What are the main organisms causing peri/orbital cellulitis?

Answer 5

Skin origin
- S. aureus
- S. pyogenes

Nasal mucosa origin
- H. influenzae
- S. pneumoniae
- M. cattarhalis

Question 6

What are the clinical signs concerning for orbital/post septal cellulitis?

Answer 6

Ophthalmoplegia
Diplopia
Reduced visual acuity
RAPD
Proptosis/Exophthalmous

Question 7

What are the causes of orbital/post septal cellulitis?

Answer 7

Spread from Rhinosinusitis
- Most common cause
Recent peri/ocular surgery
Peribulbar anaesthesia
Dental infections
Dacrocystitis
Orbital trauma
Infected mucocoele
Haematogenous spread bacteria

Question 8

What are the complications of orbital cellulitis?

Answer 8

Optic neuritis
Ischaemic injury
Pressure injury
Irreversible blindness
Local abscess/osteomyelitis
Intracranial spread
Cavernous sinus thrombosis
Cranial nerve palsies
Sepsis and death

Question 9

What are the causes of a unilateral painful red eye?

Answer 9

Acute angle closure glaucoma
Anterior uveitits/iritis
Bacterial keratitis
HSV keratitis
Corneal FB
Corneal ulcer
Contact lens over wear
Eye trauma
Episcleritis

Question 10

What are the usual features of acute glaucoma?

Answer 10

Mid dilated pupil poorly reactive
Severe unilateral headache
N/V
Photophobia
IOP >35mmHg
Hazy/cloudy cornea (oedema)
Red eye
Reduced vision
RAPD/reduced colour vision

Question 11

What is the acute treatment for acute glaucoma?

Answer 11

analgesia
antiemetics
IV acetazolamide 500mg, then PO 250mg Q6hr
Pilocarpine 2% Q15mins
Timolol 0.5% 1drop stat
Prednisolone acetate 1% stat
IV mannitol 1gm/kg
Laser iridotomy

Normal pressures 12-21mmHg, normally >40mmHg in acute glaucoma

Question 12

What are the theoretical things to do with an acute CRAO?

Answer 12

Occular massage (10seconds with eyelids closed then 5second interlude and repeat)
Statin, aspirin
Consider IV acetazolamide 500mg
ISMN or GTN for vasodilation
Stroke/Ophthal for possible thrombolysis

Question 13

If a patients visions is reduced to the point of being unable to see a snell chart, how should vision be tested from there?

Answer 13

• Count fingers starting at 3m, then 2m, then 1m, then 30cm
• If cannot count fingers then test frank hand movements at 30cm, ask them to describe or mirror with their own hand
• If cannot perceive hand movements then test light perception by shining a light in their eye in a darkened room

Question 14

What are the differentials for painful loss of vision?

Answer 14

• Corneal ulcer
• Acute glaucoma
• Acute trauma to eye
• Conjunctivitis (bacterial, viral)
• Keratitis (bacterial, HSV)
• Endophthalmitis
• Anterior uveitis
• Corneal foreign body
• Overwear of contact lenses
• Cavernous sinus thrombosis

Question 15

What is the treatment for a penetrating eye injury?

Answer 15

• Analgesia/antiemetics
• Tetanus
• Eye shield
• IV ABx (Cipfofloxacin 750mg IV and Vancomycin 20mg/kg)
• CT, bed rest, ophthal

Question 16

What are the complications of penetrating eye injuries?

Answer 16

• Endophthalmitis
• Sympathetic ophthalmia
• Retinal detachment
• Corneal scarring
• Cataracts
• Glaucoma
• Amblyopia

Question 17

What are the signs of 3rd nerve palsy and what are the causes by location?

Answer 17

Mydriasis + ptosis + eye pointing down and out

Subarachnoid space
- Aneurysm ie ICA
- herniation, trauma, tumour
- Meningitis, microvascular

Cavernous sinus
- Prominent pain, associated Horners
- Also affect IV, VI, V1 + V2
- thrombosis, carotid aneurysm

Orbital Apex
- proptosis, visual loss
- trauma, tumour, local infection

Fascicles
- Contralateral hemiparesis (Webers syndrome)
- Bleed, stroke, tumour, demyelination

Nucleus
- Contralateral ptosis + superior rectus weakness
- bleed, stroke, tumour

Question 18

What are the differentials for Anisocoria (uneven pupils)?

Answer 18

• Physiologic (20% of people)
• Iris pathology (trauma, inflammation, congenital etc)
• Traumatic mydriasis
• Horners syndrome
• 3rd nerve palsy of any cause (ie raised ICP)
• Medications ie topical miotics and mydriatics, incidental (ie salbutamol neb getting into eye)

Question 19

How do you differentiate the different types of posterior vitreous disease?

Answer 19

Question 20

What are the distinguishing features between the different cranial nerve causes of diplopia?

Answer 20