Optic Nerve and Red Reflex
Causes of optic atrophy
Optic nerve ischemia Hx of optic neuritis that has since resolved Medication Toxicity Optic nerve compression (often pituitary tumors) Radiation Damage
cortical cataract
Star-Shaped opacity. Cortical cataract shows asymmetric, radial, white spokes with black center. Through ophthalmoscope, black spokes are evident against the red reflux. Forms in outer cortex of lens, progressing faster than nuclear cataract.
Ocular histoplasmosis
Type I hypersensitivity reaction against histoplasma fungus in the eye Inflammation and redness, normal optic disc with surrounding pathology
Using the middle-sized light on an ophthalmoscope, the optic disc should be about how big?
about 3/4 the size of the light bigger in preemies
pale neuroretinal rim is called optic ______
atrophy
pigment crescent
black crescent-moon around the disc margins because of accumulation of pigment in the choroid. variant of normal
signs of papilledema
blurred margins hemorrhage
macular degeneration
breakdown or thinning of the tissues in the macula, resulting in partial or complete loss of central vision
A pale neuroretinal rim could indicate
compressive optic nerve lesion
a benign cause of enlarged optic cup would be
congenital large optic nerve head
optic disc notch
different neuroretinal rim sizes, especially smaller inferior rim vs superior
What is disc edema?
edema findings like papilledema that are NOT due to increased ICP
common causes of ischemic optic neuropathy (3)
giant cell arteritis can also be HTN, surgery with Trendelenburg position
An optic cup that takes up more than half the disc diameter is concerning for
glaucoma
optic disc notch is highly suspicious for
glaucoma
scleral crescent
gray-white new moon shape occurs when pigment is absent in the choroid layer and you are looking directly at the sclera variant of normal
What causes papilledema?
increased intracranial pressure spreads along meninges, compresses venous drainage of disc / nerve
Ischemic Optic Neuropathy
irreversible optic nerve damage due to loss of blood flow to the nerve which can lead to permanent vision loss presents with sudden painless loss of vision
A pale optic disc with blurred margins is concerning for
ischemic optic neuropathy
Subluxed lens
laxity or destruction of zonules allows lens to be pulled off-center seen in Marfan's, other CT disorders
What is a normal optic cup to optic disc ratio?
less than 0.5
what causes the red reflex?
light reflecting from the red, vascular plexus of the choroid
retinoblastoma
malignant neoplasm of primitive retinal cells
A fuzzier optic disc margin on the ______ side can be normal if everything else is normal
nasal
Papilledema would be an indicator for what testing?
neuroimaging, neuro consult, LP
A pale optic disc with sharp margins is concerning for
optic atrophy
What does ischemic optic neuropathy look like on fundoscopy?
pale optic disc of normal size with blurred margins, no visible cup/disc differentiation associated hemorrhages often visible
Normally, the color of the optic cup vs disc is
paler, maybe more yellow cup disc is darker, more pink
a very red neuroretinal rim is consistent with
papilledema
red reflex
red glow that appears to fill the person's pupil when first visualized through the ophthalmoscope
A yellow reflex in an infant's eye is a sign of
retinoblastoma
What is a normal color for the neuroretinal rim?
should be pink
pigment crescents are usually (nasal/temporal)
temporal
scleral crescents are usually (nasal/temporal)
temporal
optic cup
the depression in the center of the optic disc
Neuroretinal rim
the rim of optic disc around the optic cup
In glaucoma, the optic cup tends to enlarge in what dimension first?
vertically
nasalization of vessels
vessels pushed to nasal edge of optic disc, seen in progressive glaucoma with very severe cupping
A black reflex in the eye indicates
vitreous hemorrhage