Neuro-Ophthalmology and Orbit Flashcards
7 cards from real ABO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Neuro-Ophthalmology and Orbit flashcards as text
In the Optic Neuritis Treatment Trial, what was the main effect of IV methylprednisolone followed by oral prednisone compared with placebo?
Answer: Faster visual recovery without better long-term visual outcome
IV steroids sped up recovery but did not change final visual acuity, and the lower MS risk they showed did not last past about 2-3 years.
Which ONTT treatment arm was associated with an increased rate of recurrent optic neuritis?
Answer: Oral prednisone alone at standard dose
Oral prednisone alone (1 mg/kg/day) increased the risk of new optic neuritis attacks, so it is avoided as monotherapy.
A patient has a large pupil with segmental iris sphincter palsy, light-near dissociation, and tonic redilation. Which agent best confirms the diagnosis?
Answer: Dilute pilocarpine 0.1%
A tonic (Adie) pupil shows cholinergic denervation supersensitivity and constricts to dilute pilocarpine.
In a patient with confirmed Horner syndrome, hydroxyamphetamine 1% fails to dilate the affected pupil. Where is the lesion?
Answer: Third-order (postganglionic) neuron
Hydroxyamphetamine releases norepinephrine from intact postganglionic terminals, so failure to dilate indicates a third-order lesion.
Why does apraclonidine 0.5% reverse the anisocoria in Horner syndrome?
Answer: Denervation supersensitivity of alpha-1 receptors in the iris dilator
Apraclonidine's weak alpha-1 activity dilates the supersensitive denervated pupil, which reverses the anisocoria.
A patient cannot adduct the left eye on right gaze, has abducting nystagmus of the right eye, and convergence is preserved. Where is the lesion?
Answer: Left medial longitudinal fasciculus
An internuclear ophthalmoplegia is named for the side of the adduction deficit, which matches the side of the MLF lesion.
In one-and-a-half syndrome, which horizontal eye movement remains intact?
Answer: Abduction of the contralateral eye
A lesion of the abducens nucleus/PPRF plus the ipsilateral MLF leaves only contralateral-eye abduction.