Ophthalmology Flashcards
Acute Closure Angle Glaucoma
EM Board Bombs ep 222
PATHOPHYSIOLOGY:
- narrowing or closure of the anterior chamber angle
- aqueous humor can’t drain through the canal of schlemm
- IOP rises sharply >50mmHh
- compromises blood flow to optic nerve causing permanent vision loss
RISK FACTORS:
- asian
- female
- recent eye surgery
FEATURES:
- Acute onset eye pain + vomiting
- Headache
- Reduced visual acuity
- Tender, hard globe
- Corneal oedema “hazy cornea” –> see halos
- Fixed dilated pupil
- Ciliary flush
- IOP >30mmHg
SLIT LAMP EXAM:
- shallow anterior chamber
PRECIPITANTS (pupil dilatation)
- anything that will dilate the eye
- anticholinergics - atropine
- emotional upset
- going from light to dark lighting
MANAGEMENT:
Head of bed elevated 45degrees
Reduces aqueous humour production:
- Timolol 0.5% 1 drop every 30min
- Acetazolamide 500mg IV
- Mannitol 1g/kg (up to 50g) IV stat
Increase aqueous humour drainage:
Topical cholinergic - Pilocarpine 2% 1 drop every 15min once IOP <40 (causes miosis, decrease angle of the anterior chamber at the trabecular meshwork to increase drainage)
Apraclonidine drops (reduce aqueous humour production and increase drainage) a2 agonist
Analgesia - morphine 2.5-5mg IV
Anti-emetics - ondansetron 4mg IV
Ophthalmology review
Laser iridotomy
Peripheral iridectomy
Blunt Eye Trauma
- Globe rupture
- Retroorbital haematoma with orbital compartment syndrome
- Hyphaemas
- Orbital blow out fracture
- Retinal detachment
- Vitreous haemorrhage
Globe Rupture in Blunt Trauma
EXAM FINDINGS:
- enophthalmos (sunken eye)
- reduced visual acuity
- irregular pupil
- uveal prolapse
- chemosis
- subconjunctival haemorrhage
- RAPD
- flat anterior chamber
- hyphaema
- positive seidel test
- lens dislocation
- absent red reflex if they have vitreous haemorrhage
MANAGEMENT:
- Stop examination as soon as you diagnose globe rupture – cover eye with shield
Analgesia
- Paracetamol 15mg/kg PO/IV
- Morphine 0.1mg/kg IV
Antiemetics (prevent sudden increases in IOP with vomiting)
- Ondansetron 4mg IV
Tetanus prophylaxis - ADT
IV antibiotics to prevent post traumatic endophthalmitis
- moxifloxacin 400mg IV daily (children 10mg/kg) eTG
- ciprofloxacin 750mg IV bd (20mg/kg)
Urgent ophthalmology consult (will need surgical intervention within 24hrs)
The Red Eye
2021.1 Discussion with RMO
Discuss with RMO the approach to a patient with the red eye
Differential Diagnosis:
- acute closed angle glaucoma
- anterior uveitis
- scleritis/episleritis
- bacterial corneal ulcer
- dentritic HSV dentritic corneal ulcer
- conjunctivitis - viral, allergic, bacterial
- minor trauma - corneal abrasion, foreign body
DIFFERENTIAL DIAGNOSIS:
Painful Red Eye:
Acute closed angle glaucoma
Anterior uveitis
Episcleritis/scleritis:
- red, swelling, tender, painful, VA may decrease
- needs urgent referral to ophthalmologist
Herpes Simplex Keratitis
- vision blurred
- dendritic ulcer stains with fluorosceine
- Rx antivirals and refer to ophthalmologist
Bacterial corneal Ulcers:
- may be related to contact lens wear, foreign body or abrasion
- hypopyon indicates endophthalmitis
- needs urgent ophthalmology
Minor traumatic Keratitis (inflammation of the cornea)
- abrasion or foreign body
Painless Red Eye:
Conjunctivitis:
- Allergic (itchy, watery, bilateral, papillary lesions on inside eyelids)
- Bacterial (purulent discharge) - gonococcal conjunctivitis
- Viral (usually adenovirus, URTI, starts with one eye then second eye affected)
Subconjunctival haemorrhage
- spontaneous, vision not affected
- reassure, will gradually reabsorb
History:
Characterise the eye pain:
- scratchy ‘sand in the eye’ pain –> anterior structures
- conjunctivitis
- corneal ulcers - deep, aching pressure pain behind the eye –> posterior structures
- acute glaucoma - photophobia –> uveal tract pathology (iris and ciliary body)
- iritis
- anterior uveitis
Sudden onset pain?
- precipitant?
- going from light to dark in glaucoma
- minor trauma in corneal ulcers
Affecting one or both eyes
Vision loss or reduced
Blurred or double vision
Contact lens wearer
- corneal ulcers
- bacterial infections
Recent surgery or trauma (airbag in MVA)
- predisposes to acute angle closure glaucoma and eye infections
Medical conditions:
- inflammatory condiotions (HLA B27 associated conditions such as ankylosing spodylitis, inflammatory bowel disease
Examination:
Anaesthetise with tetracaine eye drops to optimise exam
Visual acuity:
Reduce or preserved
- Glaucoma
- Uveitis
Inspection:
Discharge - watery vs. purulent
Which part of the eye is affected
- conjunctiva and lids
- sclera (injection, pterigiums)
- cornea (hazy, scarring)
- iris (ciliary flush)
Pupils (abnormal shape, size and reactivity)
- miosis with anterior uveitis
- fixed dilated in glaucoma
RAPD
Palpate:
- focal tenderness (scleritis/episleritis)
- hard tender globe (glaucoma)
Slit lamp exam of the anterior chamber
- shallow anterior chamber (glaucoma)
- cells/flare
- keratic precipitates
- hypopyon (anterior uveitis)
- fluorescein under blue light looking for abrasions, foreign bodies and dendritic ulcers
IOP
Anterior Uveitis
Clinical Features:
- Conjunctival injection
- Scleral injection
- Ciliary flush (hyperemic perilimbal vessels)
- Miosis
- Cloudy/haze cornea
- Decreased visual acuity
- Photophobia
- Tearing and pain
- Hypopyon (Leukocytes in the anterior chamber)
Slit lamp:
- hypopyon
- cells and flare in the anterior chamber
- keratic precipitates
IOP:
- may have reduced IOP due to decreased aqueous production
- may have increased IOP secondary to inflammatory debris within the trabeculae obstructing aqueous outflow.
Complications:
Synechiae - adhesions
Glaucoma
Cataracts
Retinitis
Band keratopathy
Also accept visual loss
Painless loss of vision
Reference: Tintinalli’s
CENTRAL RETINAL ARTERY OCCLUSION:
- pale retina, cherry red spot ‘macula’
- thin bloodless arteries
- marked RAPD
Causes:
- atherosclerosis - carotid thromboembolus,
- giant cell arteritis,
- vasculitis (SLE),
- sickle cell disease
Blindness within 4hrs
- Evidence for IV tPA within 4.5hrs but urgent consult with ophthalmologist
- No evidence for digital massage, lowering IOP, or blowing into paper bag
CENTRAL RETINAL VEIN OCCLUSION:
- blood and thunder/ketchup fundus (due to venous stasis, optic disc oedema and diffuse retinal haemorrhages)
- abnormal red reflex
Risk factors:
- diabetes, hypertension, cardiovascular disease, dyslipidemia, hypercoagulable states, vasculitis, glaucoma
OPTIC NEURITIS:
- Painless or painful loss of vision
- Can be monocular or binocular
- Moderate pain with eye movement
- Associated with multiple sclerosis
- Infective causes - Measles, Mumps, chickenpox, TB, Syphylis,
- Colour vision is affected more than visual acuity, and there may be visual field deficits.
- The RED DESATURATION TEST is helpful
- Fundoscopy shows a pale, swollen, oedematous optic disc (papillitis)
GIANT CELL ARTERITIS:
- polymyalgia rheumatica, age >55yrs
- scalp tenderness, jaw claudication
- RAPD
ISCHEMIC OPTIC NEUROPATHY:
AMAUROSIS FUGAX:
- transient monocular vision loss
TIA
- transient binocular vision loss
RETINAL DETACHMENT:
- flashing lights or floaters
- increased risk in myopic patients
- partial field loss, curtain like defect
- acuity may be normal if macula not involved
- fundoscopy may show “pale billowing parachute”
- US shows the detached retina as a highly echogenic thin membrane in the posterior chamber
- US may show vitreous haemorrhage
Eye Exam
Examination:
- has to be systematic otherwise you will miss vital steps
Visual acuity:
- patients who are short sighted to wear spectacles, reading glasses (magnifiers) should not be worn
- use pinholes if patient can’t get to 6/6 to see if this improves vision
- count fingers
- hand movements
- light perception
Inspection:
- Lids (crusting, redness, swelling, entropion, ectropion)
- Conjunctiva (injection, chemosis, subconjunctival haemorrhage, lacerations, lesions - pterigiums)
- Cornea (cloudy, scarring, foreign body, rust rings)
Pupil:
- size, shape, react to light
Iris:
- tears, lacerations, prolapse
Red reflex:
- white in cataract
- distorted in dislocated lens
- absent in vitreus haemorrhage
Extra-ocular movements:
- pain, palsies
Fundoscopy
Anterior chamber:
- flat, shallow
- hyphaema
- hypopyon
- cells and flare
Intra-ocular pressure
Eye Injury
2023.2 RMO interaction
Explain to a junior doctor the approach to an eye injury.
Blunt ocular trauma
2022.1 Examination
Describe to an examiner the assessment and focused
examination of a patient who has had facial trauma and reports a loss of vision.
Diplopia
2021.2 Examination
Outline and explain to an examiner
their approach to the examination of a patient with a two day history of double vision and headache.
3rd CN (oculomotor):
- innervates all eye muscles except for lateral rectus and superior oblique
- superior rectus and levator palpebrae superiori
- medial rectus
- inferior rectus and inferior oblique
- eyelid
- pupil constriction
- accomodation (ability to focus on near objects)
Occulomotor nerve palsy:
- unilateral
- ptosis
- large unreactive pupil
- down and out position (exotropic and hypotropic)
*circle of willis aneurysm or brainstem tumour
4th CN palsy (trochlea):
-
6th CN palsy (abducens):
-
Thyroid ophthalmoplegia:
- inferior rectus involvement
Inflammatory:
- Giant cell arteritis
- Optic neuritis (multiple sclerosis)
Infection:
- Miller Fisher Syndrome (variant of Guillain-Barre)
Malignancy:
- brainstem
Metabolic:
- Wernicke’s encephalopathy
Trauma:
- rectus entrapment with orbital blow out fracture
Vascular:
- aneurysm in circle of willis
- carotid thrombosis
- cavernous sinus thrombosis
- brainstem ischemia
Endocrine:
- thyroid disease
Autoimmune:
- myasthenia gravis
Congenital:
- strabismus
Toxicological:
- neurotoxicity with snake envenomation
DIFFERENTIAL DIAGNOSIS:
*occulomotor nerve palsy
- aneurysm of the ispilateral posterior communicating artery in the circle of willis
- non-con CT to look for subarachnoid haemorrhage
- CTA circle of willis to look for aneurysm
trochlear nerve palsy
abducens nerve palsy
CN III, IV, VI palsy concerning for cavernous sinus thrombosis
Restrictive eye disorders
- inferior rectus entrapment in orbital floor blow out fracture
- inferior rectus dysfunction in thyroid disease
INTERNUCLEAR OPHTHALMOPLEGIA:
- impaired horizontal eye movement
- weak adduction in the affected eye
- abduction nystagmus in the contralateral eye
microvascular ischemia or demyelination in the medial longitudinal fasciculus in the brainstem tegmentum in either the pons or the midbrain
Pons contains the VI CN nucleus
Midbrain contains CN III - they communicate via the Medial Longitudinal Fasiculus.
NEUROMUSCULAR DISEASE:
- Myasthenia gravis
- fluctuating and fatiguability
- prolonged upward gaze test
- ice pack test
No ‘P’s allowed in myasthenia gravis
- no pain
- no perceptual disturbance (normal VA, no visual field defects)
- no parasthesia
- no pupil involvement
- no proptosis
Guillaine Barre Miller Fisher Variant
Wernicke’s Korsakoff syndrome
Demyelinating disease (multiple sclerosis)
Microvascular ischemia - diabetes, atherosclerosis
Tumour
Trauma
Raised intracranial pressure
Giant cell arteritis
History:
monocular or binocular
monocular = intrinsic eye problem
binocular = neurological
side by side or vertical displacement
acute onset = ischemic
gradual onset = tumour
transient = GCA
fatiguable = myasthenia gravis
age >50 = GCA
headache
Symptoms of GCA:
- headache
- scalp tenderness
- jaw claudication
EXAMINATION:
Visual acuity - with glasses or pin-hole
Visual fields - hemianopia, quadrinopsia
proptosis
Ptosis
strabismus on primary gaze:
- hypo/hypertropia
- exo/esotropia
pupils - size, reactivity - direct and consensual, RAPD
Ocular movements
Cranial nerve examination
Chemical Eye Injury
Acid or Alkali?
Examples of acids include:
- toilet cleaner,
- car battery fluid,
- pool cleaner.
Examples of alkalis include:
- bleach,
- lime/cement,
- drain cleaner,
- oven cleaner,
- ammonia.
Alkalis saponify ocular tissues and continue to burn deeper into the eye, hence they require more irrigation
Examination findings after irrigation:
Visual acuity
Fluorescein staining - corneal and conjunctival
Is the cornea clear or cloudy (can you see iris details)?
The degree of vascular blanching, particularly at the limbus, is proportional to severity of chemical burn
Evert eyelids – is there any retained particulate matter?
Start eye irrigation before history and examination
Insill local anaesthetic with tetracaine
eye irrigation with hartmann’s or normal saline 1L in an IV giving set on full flow
Evert the eyelids, remove any debris by sweeping the conjunctival fornices with a wet cotton bud
Irrigate the eyelids and surrounding skin
Ask the patient to look left, right, up and down while irrigating.
After the first 1L, insert a morgan lens and irrigate again
assess level of pain - apply more topical local anaesthetic if need
Review after 1L irrigation with morgan lens
check pH with litmus paper.
acceptable pH range 6.5-8.5
compare with unaffected eye
Severe burns and alkalis will usually require continuous irrigation for at least 30 minutes with 3 litres of fluid.
Orbital Cellulitis
EM Rapid Bombs ep 43
CAUSATIVE ORGANISMS:
- Staphy aureus
- Strep pneumoniae
- Haemophilus influenzae type b (in those who are not immunised)
CAUSES:
- paranasal sinusitis
- trauma - penetrating injury
- ocular surgery
- seeding from bacteremia
- intra-orbital foreign body
- pre-septal cellulitis (cellulitis around the eye)
CLINICAL FEATURES:
- painful eye movements
- limited extra-ocular movements (ophthalmoplegia)
- reduced VA
- proptosis
- chemosis
- RAPD
- increased IOP (orbital abscess)
- Headache and fever with deficits of cranial nerves III, IV, or VI suggest cavernous sinus thrombosis.
INVESTIGATION:
CT orbit with contrast
- orbital cellulitis diagnosed with CT
- oedema of orbital contents
- abscess
- can assess for causative sinusitis
- assess for complications - intracranial abscess and cavernous sinus thrombosis
MANAGEMENT:
Urgent ophthalmology consult
IV antibiotics:
ceftriaxone 2g IV daily (50mg/kg IV Q8h)
PLUS
Flucloxacillin 2g IV Q6h (50mg/kg IV Q6h)
Penicillin allergy:
ciprofloxacin 400mg IV Q12 (10mg/kg IV Q12h)
PLUS
vancomycin 25-30mg/kg IV loading dose
Disposition:
Admission
May need surgical drainage or lateral canthotomy
COMPLICATIONS:
- permanent vision loss
- intraocular abscess
- intracranial abscess
- epidural abscess
- subdural empyema
- frontal bone cellulitis
- meningitis
- cavernous sinus thrombosis
- orbital compartment syndrome requiring lateral canthotomy
2 DIFFERENTIAL DIAGNOSES FOR PROPTOSIS/EXOPHTHALMOS:
- cavernous sinus thrombosis
- retro-orbital haemorrhage or abscess
Acute painless vision loss
EM Rapid Bombs 200 (CRAO)
ep 204 (CRVO)
CENTRAL RETINAL ARTERY OCCLUSION -
thromboembolism from carotid atherosclerosis
Pale retina, cherry red spot, asymmetric red reflex, RAPD
digital massage is not effective
urgent consultation with ophthalmology and stroke neurologist for consideration of thrombolysis if within 3hrs
loss of vision witin 4hrs
CENTRAL RETINAL VEIN OCCLUSION -
Diabetes, glaucoma
“Blood and thunder”/”ketchup” fundus - tortuous dilated retinal veins with diffuse haemorrhages
optic disc oedema
abnormal red relfex
RAPD
RETINAL DETACHMENT- advancing age, hx of myopia - visual field defect, “cloudy veil,” “window shade”
abnormal red reflex
RAPD
POCUS examination - linear probe
visualise the optic nerve
retina attached to optic nerve
vitreous detachment not attached to optic nerve
VITREOUS HAEMORRHAGE - trauma - opacity in the vitreous, floaters, cobwebs
AMAUROSIS FUGAX - normal fundoscopy, transient vision loss
CMV RETINITIS - “Tomato and cheese” pizza (retinal necrosis), retinal hemorrhages
Acute ischemic optic neuropathy
Giant cell arteritis
- jaw claudication
- scalp tenderness
- temporal beading
- associated polymyalgia rheumatica
Hyphaema
Hyphema - blood in the anterior chamber
Complications:
- increased intraocular pressure (glaucoma)
- rebleeding (day 3-5)
- peripheral anterior synechiae
- corneal staining
- optic atrophy
- accommodative impairment
Management
Bed rest with head of bed up at 45 degrees - promotes sedimentation, clears angle, reduces rebleeding
Rest the eyes - eye shield, no reading or watching tv (prevents rebleeding)
Treat pain and nausea - opiates, panadol, anti-emetics (prevents raised IOP) - avoid NSAIDs
Tranexamic acid - reduce rebleeding
Cycloplegics - atropine - prevent posterior synechiae
Topical steroids may prevent posterior synechiae
Ophthalmology consult and admission for patients with hyphemas >1/3 of the anterior chamber - as may require surgical anterior chamber “washout”
acetazolamide 500mg iv, timolol 0.5% q1h - reduce IOP
Medications:
*cycloplegics
*acetazolamide 500mg iv, timoptol 0.5% twice daily if increased intraocular pressure
*avoid aspirin and other NSAIDs
