Flashcards in Lecture III Deck (66):
What is the definition of *acute* visual loss?
Loss of vision within 72 hours
What is the major cause of optic nerve dysfunction in young patients?
What is the first media that light has to pass through to get to the retina? How significant is pathology in this area?
What are the refractive media that light passes through to get to the retina?
What are the common causes of corneal edema?
-*Closed angle glaucoma*
True or false: any infx/inflammation of the eye may mimic corneal edema
What happens to the cornea with edema?
Crisp, clear cornea becomes dull, ground glass appearance
What is usual presentation of acute angle closure glaucoma?
Acute onset of severe ocular pain, with a rock hard eye
What happens to the pupil with acute angle closure glaucoma?
Mid-dilated, fixed pupil
What happens to vision with acute angle closure glaucoma?
Halos around light
What are the extraocular s/sx of acute angle closure glaucoma?
What, generally, happens with acute angle glaucoma?
Iris closes the canal of schlemm, causing a buildup of pressure in the eye
What is hyphema?
a collection of blood anterior chamber The blood may cover part or all of the iris and the pupil, and may partly or totally block vision in that eye.
What generally causes hyphema? What other, lesser cause?
Trauma to the eye
Neovascularization of the eye
What are lenticular changes?
Cataracts (clouding of the lens)
What are the common etiologies of vitreous hemorrhage? (3)
How do you diagnose vitreous hemorrhage?
Dilate pupil and a fundoscopic exam
How fast do vitreous hemorrhages resolve relative to hyphema?
What is vitreous detachment?
Vitreous separates from the retina, causing the vitreous humor to liquefy, shrinks, and forms opacifications that can be visualized within the visual field
What are the common etiologies of vitreous detachment?
What age range is commonly affected with vitreous detachment?
Over 45 yo
What are the hallmark s/sx of retinal detachment?
Flashes of light and floaters, followed by a shade in the visual field
How does retinal detachment begin and spread?
Begins peripherally, and dissects posteriorly
How do you diagnose retinal detachment?
Through a dilated pupil, generally by an ophthalmologist
What are the three leading causes of blindness in the US?
2. Macular degeneration
What are the two forms of macular degeneration?
Dry and wet forms
What is the difference between dry and wet forms of macular disease?
Wet = neovascularization behind the retina which can leak exudate and fluid and also cause hemorrhaging
Dry = cellular debris called drusen accumulates between the retina and the choroid, causing atrophy and scarring to the retina
Which form of macular degeneration causes a sudden loss of vision: dry or wet? Which is usually worse?
What is amaurosis fugax?
Sudden occlusion of the temporal artery, causing a sudden (total) and transient visual loss
Cholesterol plaque in the retina probably came from which vessels?
What are the three major organ systems that should be evaluated with amaurosis fugax?
What is a common mimic of amaurosis fugax? Why?
Migraine--so much vasospasm causes occlusion of retinal
What is the most common visual symptoms of migraines?
What should always be evaluated with new onset migraines?
Ask about family h/o migraines
What is CRAO?
central retinal artery occlusion
What are the s/sx of central retinal artery occlusion?
Sudden, painless visual loss
True or false: central retinal artery occlusion is an ocular emergency
What is the appearance of the eye with central retinal artery occlusion after hours of occlusion?
-Opaque retina with *cherry red spot*
What happens to vision with central retinal artery occlusion?
only light perception, or worse
What happens to the pupil with central retinal artery occlusion?
Relative afferent defect
What are the retinal changes with central retinal artery occlusion in the first minutes to hours?
Vascular stasis, boxcarring
What is the immediate treatment for central retinal artery occlusion?
Digital massage compress eye with heel of hand firmly for 10 seconds, then release to 10 seconds to attempt to relieve occlusion
What are the medications that can be used in central retinal artery occlusion?
Glaucoma meds--takes pressure down to 0
What are the characteristics of the eye in the months following central retinal artery occlusion?
Blind eye with a pale optic disc, but the vessels will recannulate
What is BRAO? What usually causes it? What are the usual results?
branch retinal artery occlusion, usually caused by an embolus
Only a branch of the central retinal artery involved--may just cause peripheral vision loss
What are the common sources of branch retinal artery emboli? (4)
The scotoma seen with branch retinal artery occlusion depends on what?
Size and location of the branch that is occluded
What is the outcome of branch retinal artery occlusion?
Depends on the branch involved, but may be nothing
What are the general s/sx of central retinal vein occlusions?
Often severe vision loss, but onset is subacute
What is the classic appearance of CRVO?
"Blood and thunder"
-Diffuse retinal hemorrhages
-cotton wool spots
Who generally gets CRVO?
Older patients with CVD
What is the major late complication of CRVO?
What is optic neuritis? What can this lead to?
Idiopathic inflammation of the optic nerve
may be indicative of MS
What is the prognosis of optic neuritis?
90% of vision comes back, especially if first attack
What is the classic sign of optic neuritis?
How do you treat optic neuritis?
How does glaucoma cause corneal edema?
Fluids overwhelms the Na/K pump
What may happen as a result of a hyphema?
Clogging of the trabecular meshwork, which can causes increased IOP days later
What is the general MOA of cycloplegic agents?
Paralysis of the ciliary muscle
M3 receptor blocker (muscarinic antagonist)
What happens when a person with a hyphema sits up?
The blood in the anterior chamber will settle inferiorly, clearing the vision
What are the general complaints that occur with vitreous hemorrhage?
Cobweb-like floaters in their visual field
What are the major consequences that can occur with retinal detachment? (2)
-If blood vessels affected, then massive hemorrhage within the eye
-If involves macula, will lead to blindness.
What, generally, happens with retinal detachment?
Retina detaches, and causes the vitreous humor to fill in behind it, further detaching the retina
What may cause a sudden onset of macular degeneration?
neovascular membrane that grows beneath the retina causes distortion
What are the two types of migraines?
Cephalic and acephalic