Acute Visual Loss Flashcards
Important info to get from pt history
Is the visual loss transient or persistent; monocular or binocular?
Over what time frame did it occur (rapidly, hours, days, weeks, etc.)?
Pt’s age, race, medical conditions?
Pain associated w/ the loss?
Media opacities
irregularities of the clear refractive media; cornea, anterior chamber, lens, vitreous; won’t cause an APD but can physically alter the pupil
corneal edema: appearance, cause, implications
- dulling of the reflection of incident light off the cornea
- ground glass appearance
- caused by increased IOP or damage to corneal tissue by dystrophies, trauma or surgery
- can cause acute infections or corneal inflammation
acute angle closure glaucoma: symptoms, tx
- a true emergency!
- S&S = intense pain, fixed pupil, very red eye, corneal edema, very high IOP
- tx by laser iridotomy
hyphema: definition, causes
- blood in the anterior chamber
- usually traumatic but occurs spontaneously in rubeosis (neovascularization of the iris)
- neovascularization can be caused by diabetes, tumors, status post surgery, chronic inflammation
hypopion
- WBCs forming pus in the anterior chamber
- usually from infection
- can be sterile (accumulation of inflammatory debris)
- could cause cornea to look like it’s “melting”
lenticular changes
- cataracts usually develop slowly
- advanced cataracts may acutely cause inflammation or glaucoma (rare in the US)
- sudden changes in blood sugar or electrolytes may cause lens edema and shift in refractive error – yay diabetes!
- everyone gets cataracts to a certain degree; the leading cause of preventable blindness worldwide
- appears as a yellowing/browning of the lens; could look like cinder in the middle of the red reflex
vitreous hemorrhage
- reduction in vision from opaque blood blocking light; will have poor red reflex
- could be caused by trauma or conditions causing neovascularization (diabetes mellitus or branch retinal vein occlusions)
- could be associated w/ a subarachnoid hemorrhage
- if you see the lens is clear but you can’t see the fundus suspect a vitreous hemorrhage
retinal detachment
- pt c/o flashing lights, floaters, curtain/cloud in vision W/O pain
- could only present w/ flashes of light and new onset floaters
- could cause an APD, might see elevated retina w/ folds
Macular disease
- painless reduction in VA
- most commonly caused by subretinal neovascularization from age related macular degeneration
- # 1 cause of blindness in US (and other developed countries)
- may or may not have APD
- central metamorphosia (wavy vision)
- wet and dry versions; can slow progression from dry to wet w/ nutritional supplements
retinal vascular occlusion
- transient monocular loss is amaurosis fugax (something blocked blood flow temporarily and then it cleared - vision loss occurs then goes back to normal/near normal)
- if pt is 50+ suspect carotid circulation as cause i.e. an embolus from the carotid
central retinal artery occlusion
- sudden painless usually complete visual loss (NLP)
- permanent damage to ganglion cells and inner retina
- early findings include narrowed arterioles; cell death occurs causing white retinal edema after several hours
- will see a “cherry red spot” in the fovea (like you would see in Tay-Sachs)
- true emergency!
- tx by trying to change the intravascular pressure/resistance: attempts to dislodge the embolus by compression or paracentesis of anterior chamber
- 50% 5-year mortality rate; the CRAO doesn’t cause death but the underlying cardiovascular condition does
retinal vein occlusion
- painless subacute loss of vision
- caused by HTN, DM, vasculopathies, AV nicking
- optic disc swells, venous engorgement, cotton wool spots, diffuse retinal hemorrhages; “blood and thunder” fundus
- can tx w/ ASA QID; some forms may need laser tx; can lead to neovascular glacoma
optic neuritis
- inflammation of optic n.
- can be associated w/ MS, intracranial mass, aneurysm
- reduced VA, often +APD, contrast sensitivity and visual field diminished
- usually pain w/ eye movements
- get MRI to r/o tumor, aneurysm, etc.
- if MS you can tx w/ high dose methylprednisolone 1g IV over 45 minutes QID x 5d –> DO NOT tx w/ PO steroids always use IV first
papillitis v. papilledema
papillitis = optic n. inflammation
papilledema = swelling of optic disc from increase ICP; has to be BILATERAL finding; caused by tumor, hemorrhage, malignant HTN, etc.
- test question setup = 20-30yof overweight w/ dull headache w/ unremarkable PE except for papilledema –> answer = pseudotumor cerebri (idiopathic increased ICP)
ischemic optic neuropathy
- optic n. edema causing painless vision loss
- 2 types = arteritic and nonarteritic
- arteritic = medical emergency; giant cell (temporal) arteritis; can wipe out the optic n. very quickly
- nonarteritic = not caused by inflamed a./vessel; not an emergency; anterior ischemic optic neuropathy
giant cell (temporal) arteritis
- systemic disease rarely in pts when pt moves mouth/talks the jaw tightens
- if suspected get a sed rate and CRP
- if sed rate over 60 tx w/ 100mg corticosteroids and an H2 blocker or PPI to protect the stomach and get a temporal a. biopsy for a definitive dx - don’t wait to tx
traumatic optic neuropathy
- hx of trauma, vision loss, +APD, +/- other ocular damage
- shearing of vascular supply to optic n.
- compression - hematoma in optic canal, optic n. avulsion, bone fragment impinging n.
- poor prognosis: tx w/ high dose steroids, could require orbital or neurosurgery
homonymous and bitemporal hemianopia; what the losses are and the most common location of injury causing them
homonymous hemianopia = same side loss in both visual fields; usually lesion behind the optic chiasm
bitemporal hemianopia = loss of the right half of the OD field and left half of the OS field (tunnel vision); usually lesion at optic chiasm i.e. pituitary tumor
cortical blindness
- aka central or cerebral blindness
- extensive b/l damage to cerebral visual pathways
- complete loss of vision, normal pupillary light response and normal fundus exam
functional (nonphysiologic) visual loss
- preferred term over hysterical or malingerer
- hysteria = extreme emotional stress; malingering = seeking secondary gain, often obnoxious and uncooperative
- PE = none other than psychophysical
- vision change may sound bizarre when described
- can do your own placebo effect experiment = “magic drop” test
