aka Ophthalmology Befuddler 028
We’re coming to the end of an absolutely eyeful Ophthalmology August here at LitFL. Over the month we’ve considered many different causes of loss of vision. Today’s Q&A’s will bring together all the different ways the ‘lights can go out’ — don’t forget keep your ultrasound machine handy…
Are you ready for the ‘out of sight / loss of vision challenge’?
Anyone else had an eyeful of ophthalmology yet? (photo by y.caradec --- click image for source)
Questions
Q1. What are the important nontraumatic causes of transient (<24h) monocular vision loss?
Common causes of non-traumatic transient visual loss include:
- amaurosis fugax (usually minutes) — usually embolic or thrombotic; can occur secondary to hypoperfusion states, hyperviscosity or vasospasm.
- migraine (can be without headache)
- one eye closed!
Uncommon causes include:
- papilloedema (may be associated with visual loss lasting seconds)
- other causes of ischemic optic neuropathy, e.g. giant cell arteritis
- impending central retinal vein occlusion (CRVO)
- glaucoma
- posterior reversible encephalopathy syndrome (PRES)
- large vessel occlusion or dissection, e.g. ocular ischemic syndrome (carotid occlusive disease), vertebrobasilar insufficiency, and carotid or vertebral artery dissection
- functional visual loss, e.g. hysteria, malingering
Q2. What are the important nontraumatic causes of acute persistent monocular vision loss?
Painless acute persistent loss of vision:
Painful acute loss of vision:
- acute glaucoma
- endophalmitis
- uveitis
- keratoconus (vision can deteriroate rapidly and is associated with photophobia)
Q3. What are the important nontraumatic causes of acute binocular loss of vision?
Transient
- migraine
- VBI (transient)
Prolonged
- CVA
- poisons/ toxic optic neuropathy (e.g. methanol, quinine, ethambutol, ergot alkaloids, salicylates)
- posterior reversible encephalopathy (PRES)
- optic or retrobulbar neuritis
- hysteria
- malingering
Q4. What are the important post-traumatic causes of loss of vision?
From ‘front to back’:
- lid injury
- corneal irregularity or laceration
- hyphema
- ruptured globe
- traumatic cataract
- lens dislocation
- commotio retinae
- retinal detachment
- retinial or vitreous hemorrhage
- intra-ocular foreign body
- traumatic optic neuropathy or optic nerve avulsion
- CNS injury
Q5. What important cause(s) of visual loss should be suspected if the following features are present?
[Based on Jeff Mann's clinical clues]
central loss of vision
optic nerve disorders, macular degeneration, diabetes mellitus
visual loss that respects the horizontal midline (‘altitudinal’)
‘prechiasmal’ lesions — optic neuritis, optic neuropathies, glaucoma, branch retinal vein occlusion
visual loss that respects the vertical midline
‘postchiasmal’ lesions — ischaemia, hemorrhage, tumors, inflammation, trauma
Loss of vision in one eye
Eye or optic nerve pathology
Loss of vision in both eyes
Visual pathway pathology, bilateral optic neuritis, bilateral ischemic optic neuropathy (cerebral arteritis), toxic optic neuropathy
Sudden onset of painless loss of vision
Central retinal artery occlusion, acute ischemic optic neuropathy, vitreous hemorrhage
Patient does not complain of visual loss, but bumps into objects when ambulating
Temporal vision field defect with macular sparing
Cloudy vision with floaters
Retinal detachment, vitreous hemorrhage
Flashing lights experience
Retinal detachment
Curtain-like veil obscuring vision
Retinal detachment
Curtain coming across vision like a shutter from above or below
Central retinal artery occlusion
Vague central vision obscurations — “fluffy ball” or “puff of smoke”, or complaint of a sensation of “looking through ground glass”, or a claim that vision would be normal if he could only “see around it”
Optic neuritis
Transient visual obscurations during any movement or change of position such as bending, straining or getting up suddenly
Papilledema
Previous transient visual obscurations lasting seconds
Papilledema, retinal vein occlusion
Previous transient visual obscurations lasting minutes
Amaurosis fugax
Photopsias (positive visual phenomena — spontaneous flashing squares, flashes of light, showers of sparks) precipitated by eye movements
Optic neuritis
Visual blurring made worse by hot weather or hot shower
Optic neuritis
Visual distortions such as metamorphosia (straight lines are bent) or micropsia (objects appear smaller)
Retinal detachment, macular degeneration, sub-retinal hemorrhage or edema
Eye pain at rest
Iritis, acute angle-closure glaucoma, compressive intraorbital pathology
Eye pain with eye movements
Corneal lesions, iritis, optic neuritis, intraorbital infiltrative or compressive pathology
Diffuse or localised headache, pain on combing the hair, temporal area pain especially when laying the head down on a pillow, jaw claudication, prolonged unexplained fever, malaise, weight loss, proximal myalgias, age > 50
Temporal arteritis and secondary acute ischemic neuropathy or retinal artery occlusion
Visual loss with diplopia
Intra-orbital, orbital apex pathology
Visual loss with focal neurological symptoms or signs
CNS lesion (e.g. stroke) affecting the visual pathways
Recent trauma
Remember Q4?
Traumatic cause of loss of vision from ‘front to back’ include:
lid injury, corneal irregularity or laceration, hyphema, ruptured globe, traumatic cataractm lens dislocation, commotio retinae, retinal detachment, retinal or vitreous hemorrhage, intra-ocular foreign body, traumatic optic neuropathy or optic nerve avulsion, CNS injury
HIV
HIV retinitis, CMV retinitis, toxoplasmosis or histoplasmosis retinitis
And to finish, check out another fantastic video by Dr Sam Tapsell; this one summarizes the visual fields and vision loss:
References
- Ehlers JP, Shah CP, Fenton GL, and Hoskins EN. The Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease (5th edition), Lippincott Williams & Wilkins 2008.
- Jeff Mann’s EM Guidemaps. Loss of vision.
- Marx JA, Hockberger R, Walls RM. Rosen’s Emergency Medicine: Concepts and Clinical Practice ( 7th edition), Mosby 2009. [mdconsult.com]
About Chris Nickson
