Neuro-Ophthalmology Flashcards
Nerve fibers (of the nerve fiber layer) will respect ______
Horizontal line
Nerve fibers (of the nerve fiber layer) will travel _____ until the first synapse on the _______
12cm, LGB
Visual cortex cells are____
Simple vs Complex
Visual cortex cells - Simple cells function
Linear orientation of the visual field
Visual cortex cells - Complex cells function
Linear orientation of the visual field with the direction of movement (best for movement perception)
State the percentage of cells that decussate at the chiasm and the side that decussate.
53% and nasal
The macular diseases will usually present with:
Metamorphosis\ Microopsia (actual location change of photoreceptors)
The ON diseases will usually present with:
COLOR perception!
VA to some extent as well.
Ischemic optic neuropathy usually presents with what VF deficit?
Lower arc in the lower visual field
Examination of the ON includes
VA, Color perception, RAPD
Pupillary light reflex pathway - First neuron and its output and synapse.
Light —(via CN II)—>pretectal nuclei in the midbrain
Light —(via CN II)—>pretectal nuclei in midbrain—-(decussation)—->bilateral Edinger Westphal nuclei–(via CN III)–>Cilliary ganglion—->Ciliary sphincter
pupils constrict bilaterally (direct and consensual reflex).
Result: illumination of 1 eye results in bilateral pupillary constriction.
Pupillary light reflex pathway - Second neuron and its output and synapse.
pretectal nuclei in midbrain—-(decussation)—->bilateral Edinger Westphal nuclei
Light —(via CN II)—>pretectal nuclei in midbrain—-(decussation)—->bilateral Edinger Westphal nuclei–(via CN III)–>Cilliary ganglion—->Ciliary sphincter
pupils constrict bilaterally (direct and consensual reflex).
Result: illumination of 1 eye results in bilateral pupillary constriction.
Pupillary light reflex pathway - Third neuron and its output and synapse.
bilateral Edinger Westphal nuclei–(via CN III)–>Cilliary ganglion
Light —(via CN II)—>pretectal nuclei in midbrain—-(decussation)—->bilateral Edinger Westphal nuclei–(via CN III)–>Cilliary ganglion—->Ciliary sphincter
pupils constrict bilaterally (direct and consensual reflex).
Result: illumination of 1 eye results in bilateral pupillary constriction.
Pupillary light reflex pathway - Fourth neuron and its output and synapse.
Ciliary ganglion—->Ciliary sphincter
Light —(via CN II)—>pretectal nuclei in midbrain—-(decussation)—->bilateral Edinger Westphal nuclei–(via CN III)–>Cilliary ganglion—->Ciliary sphincter
pupils constrict bilaterally (direct and consensual reflex).
Result: illumination of 1 eye results in bilateral pupillary constriction.
Disc examination:
Color (usually yellow-orange), Size (edematous/atrophied?), Shape (Congenital anomaly?)
Swollen disc usually results from____ at ____
Axoplasmic transport obstruction, Lamina cribosa (narrowest place)
Reasons for the increase in ICP and Papiloedema:
SCHMOCE!
S - SOL C - Craniosynostosis H - Hydrocephalus M - Meningitis O - Obstruction of venous outflow (sinus vein thrombosis -CSF has nowhere to go) C - CSF secreting tumors E - Edema
Papilledema examination - describe normal finding
Oval shape, clear borders, and blood vessels exiting from it with a cup in the middle.
Papilledema examination - neurologically we care most for the ____
Rim
Papilledema examination - we look for _____
blurring of the borders, and blood vessels
Pseudotumor cerebri etiologies:
Femal TOAD
Female Tetracyclines Obesity/OSA Vitamin A overdose Danazol
Pseudotumor cerebri symptoms:
Headache, Photophobia, N/V, “DVT”
D - diplopa (horizontal - CN VI)
V - Visual obstruction (transient with position change)
T - Tinitus
Pseudotumor cerebri findings:
Field PACS
Field - VF has increased the blind spot
P - Papilledema
A - Acuity decrease (not in the early stage)
C - Color perception decrease (not in the early stage)
S - Symetric
Pseudotumor cerebri treatment:
CLaWS C - CAI L - LP (from week 16-20) a W - weight loss (6-10%) S - Steroids (when approaching surgery/catastrophic edema) S - Surgery
Pseudotumor cerebri treatment - surgery indications:
Sever optic neuropathy or lack of response to medical treatment.
Pseudotumor cerebri treatment - surgical options:
Shunts (VP or Lumopertoneal) - risk of obstruction in 50% of cases.
Optic nerve decompression - risk of injury to blood vessels. ON, Diplopia, infections.
Pseudotumor cerebri workup:
MRI/CT
LP opening pressure (normal is 80-200mm water, >250mm water is diagnostic for PTC)
Pseudotumor cerebri workup - atypical patient mandates ____ for worry of_____
MRI and CTV/MRV for risk of sinus vein thrombosis.
Anterior Ischemic Optic Neuropathy (AION) Pathophysiology:
Area affected
Ischemic damage to ON at the prelaminar area (close to exit location of the eye)
Anterior Ischemic Optic Neuropathy (AION) ocular signs, symptoms, and fundus exam findings:
Sudden painless vision loss with RAPD.
Edema and flame-shaped bleeds (on an exam)