Acute Visual Loss
Terms
undefined, object
copy deck
- 5 thing to ask about acute visual loss
-
transient vs. persistent
monocular or binocular
abrupt vs. hours, days wks
pts age and pmh
documented normal vision in the past - Exam in acute visual loss
-
visual acuity
confrontation field testing (uncovers homonymous hemianopia)
pupillary reaction (damage to retina or nerve will send less light to brainstem -> Marcus Gunn pupil)
Ophthalmoscopy
Penlight exam (for corneal disease)
Tonometry for glaucoma - What is the Marcus Gunn pupil
- when light moved from normal to abnormal eye the pupil of abnormal eye will continue to dilate (relative afferent pupillary defect) = positive swining flashlight test
- What is the relative afferent pupillary defect represent
- Damage to afferents is a sign of monocular visual loss
- What are the 4 clear refractive media of the eye?
-
cornea
anterior chamber
lens
vitreous humor - Damage to clear refractive media causes what symptoms
- blurred vision but no relative afferent pupillary defects
- What 2 things can cause altered pupillary reflexes
-
miosis in acute iritis
middilated and fixed pupils in acute angle-closure glaucoma - What is observed in corneal edema?
- sudden opacificiation of the cornea -> dulling of light reflecting off the cornea resulting in ground glass appearance
- What is the most common cause of corneal edema?
- increased IOP. Conreal edema is what causes vision loss in angle closure glaucoma
- What condition can mimic corneal edema?
- acute infection or inflammation (HSV keratitis)
- What two conditions cause gradual onset of vision loss due to coreal edema?
- damage to corneal endothelium by dystrophies or following cataract surgery
- Blood in the anterior chamber is known as ____
- hyphema
- What 4 conditions predispose to hyphema?
-
abnormal vessels due to:
tumors
DM
intraocular SGY
chronic inflammation - What 2 conditions can alter hydration of the lens
- Suddent changes in blood sugar or serum electrolytes can cause large fluctuations in refractive error interpreted as visual loss by pt
- In what case does cataract produce acute visual loss
- When it progresses rapidly
- What 3 conditions will cause vitreous hemorrhage
- trauma, retinal neovascularization (DM & retinal vein occlusion), and subarachnoid hemorrhage (aneurysm rupture)
- Under what conditions should vitreous hemorrhage be suspected
- Clear anterior chamber and lens but retina cannot be seen
- 3 inflammatory processes affecting the retina that will result in acute visual loss
-
infectious chorioretinitis
vasculitides
idiopathic inflammation - What are the symptoms of retinal detachement
- Large number of floaters then shade over the vision in one eye, relative afferent pupillary defect in involved eye
- What is found on retina in retinal detachmeht
- elevated retina +/- folds and indistinct choroid background
- What causes suddent visual loss ini macular disease?
- bleeding from neovascular net formed in macular degeneration
- ____ is a defect of central vision in which shapes of objects appear distorted, seen due to neovascularization in macular degeneration
- metamorphopsia
- What is the treatment for metamorphopsia
- laser surgery before progression to significant and permanent visual loss
- Loss of vision in one eye lasting for several minutes is suspicious for ____
- amaurosis fugax, suspect ipsilateral carotid artery disease
- What are the 3 signs of central retinal artery occlusion
- suddent painless and often complete visual loss
- Vascular stasis is seen in __(time range)__ of central retinal artery occlusion
- minutes to hours
- What are the two thing seen in vascular stasis
-
narrowing of arterial blood columns
interruption of venous blood columns -> appearance of bloxcarring - rows of corpuscles are separated by clear intervals - How long after centra retinal artery occlusion will the cornea become opalescent?
- Several hours
- What causes the cherry-red spot in central retinal artery occlusion?
- pallor of the perifoveal retina standing out in contrast to the normal color of the fovea, also seen in Tay-Sachs and Neimann-Pick due to metabolite deposition
- What causes swelling of the optic disc?
- Occlusion of the ophthalmic or carotid artery (proximal to the origin of the central retinal artery) - some vision may be spared in complete centra retinal A occlusion
- In what case can part of the retina be spared in central retinal artery occlusion?
- If part of the retina is supplied by choroidal circulation via a celioretinal artery
- What causes pallor of the disc in the blinded eye months after central retinal artery occlusion?
- As the edema resolves and ganglion cells die their axons atrophy
- How long is the window for treating central retinal artery occlusion
- Several hours
- What techniques could potentially dislodge the embolus blocking the central retinal artery?
-
rise in fall in IOP by pressing and releaseing the eye in 10sec intervals for 5 min
injeciton of anesthetic and paracentesis of anterior chamber - What can be used to treat branch retinal artery occlusion
- ocular massage
- What causes branch retinal artery occulusion
- usually embolus
- 5 signs of central retinal vein occlusion
-
disc swelling
venous engorgement
cotton wool spots
diffuse retinal hemorrhages
subacute onset - What is the treatment for central retinal veing occulsion?
- No standard treatment, not a true ophthalmic emergency
- What are 4 risk factors for central retinal vein occlusion
-
age
HTN
atherosclerotic vascular disease
disease affected blood viscosity (polysythemia vera, SCD, leukemia/lymphoma) - What 3 things take place as central retinal vein occulsion resolves?
-
swelling resolves
shunt vessels develop from retinal to choroidal circulation
and ocular neovascularization (risk of neovascular glaucoma - need laser) - What is the initial appearance of the optic nerve in acute visual loss in optic nerve disease?
- nerve may or may not look normal but pupillary response is abnormal
- What causes optic neuritis
-
usually idiopatic
may be associated with MS - What is the appearance of the optic nerve in optic neuritis
- hyperemic and swollen
- What is the prognosis for return of vision after optic neuritis?
- good
- What is the treatment for acute optic neuritis
- corticosteroids
- Classic presentation for retrobulbar optic neuritis (5 items)
-
young adult
vision loss over hours - days
pain with eye movement
normal ophthalmic exam but poor vision
afferent pupillary defect - What is the differential diagnosis for retrobulbar optic neuritis?
- comprehenssive optic neuropathy
- How is retrobulbar optic neuritis diagnosed?
- MRI or CT, will show lesion compressing nerve
- What are 2 subtypes of optic neuritis and findings
-
retrobulbar optic neuritis
papillitis
significantly decreased vision
relative afferent pupillary defect - What is papillitis?
- Inflammation of the optic disc or papilla
- What is papilledema?
- swelling of the optic disc from increased ICP, bilateral
- In papiledema what is the effect on visual acuity and pupillary reflexes
- These are normal but some pts have momentrary bulurring or transient oscurations of vision
- What is the long term effect of acute papilledema
- minor alternations in vision if any
- What should be suspected in an older pt with swelling of the disc and visual loss
- vascular event (ex. giant cell atreritis), noninflammatory
- What is the presentation of ischemic optic neuropathy? (5)
-
pale, swollen disk
+/- splinter heme and
loss of vusial acutity and visual field - What is the pattern of visual loss seen in schemic neuropathy?
-
altitudinal
superior or inferior field - What are the symptoms of systemic giant cell arteritis? (4)
-
malaise
limb girdle pain
scalp tenderness/pain combing hair
pain on chewing (jaw claudication) - What test should be ordered for an elderly pt with ischemic optic neuropathy or unexplained ophthalmoplegia
- ESR, look for >60 for giant cell arteritis
- What is the treatment for giant cell arteritis?
- high dose corticosteroids
- What will be find on temporal vessel biopsy in giant cell arteritis? (3)
-
giant cells
fragmentation of the elastica with surrounding chronic inflammation
occlusion of the vessel - What is the chance for contralateral eye involvement in nonarteritis ischemic optic neuropathy?
- 40% chance
- loss of vision on one side of both visual fields is called ____
- homonymous hemianopia
- What can cause homonymous heminanopia?
- occlusion of one of the posterior cerebral arteries with infaction of occipital lobe, or MCA occlusion (will have other symptoms)
- What tests should be ordered in a patient with homonymous hemianopia?
- cerebral CT or MRI
- What causes cortical blindness
- extensive bilateral damate othe cerebral visual pathways -> complete vision loss
- What are the 2 findings on ophthalmic exam in a patient with cortical blindness
-
normal pupillary reactions
normal fundus - What is the prognosis of a pt with cortical blindess
- either improvement or death due to severe neurologic damage
- What causes functional acute visual loss
- hysteria or malignering
- What are the findings in functional visual loss?
-
normal pupillary reactions
normal stereopsis if one eye is "affected" - Why can chronic visual loss be an acute discovery?
- Vision is normal in one eye and the patient does not notice