Pupils and Reflexes in Ophthalmology

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Which muscle is responsible for miosis?

Ciliary

Sphincter (correct)

Pupillary

Dilator (radial)

Which cranial nerve is responsible for carrying motor impulses from the CNS to the muscles of the iris?

Cranial nerve II

Cranial nerve V

Cranial nerve III (correct)

Cranial nerve VII

What is the purpose of the swinging flashlight test?

To diagnose cranial nerve III palsy

To test for afferent pupillary defect (correct)

To check for Horner's Syndrome

To measure the pupil's response to light

What is the result of a lesion anterior to the chiasm?

Afferent pupillary defect Signup and view all the answers

What is the function of the Edinger-Westphal nucleus?

To regulate the pupillary light reflex Signup and view all the answers

What is the term for the phenomenon of rhythmic fluctuations in pupillary size due to an imbalance between sympathetic and parasympathetic innervation?

Pupillary hiccup Signup and view all the answers

What is the term for the measurement of the relative difference in pupillary constriction between the two eyes?

RAPD Signup and view all the answers

What is the purpose of using neutral density filters in pupillary testing?

To quantify the relative afferent pupillary defect Signup and view all the answers

What is the significance of the direct response being equal to the consensual response?

The afferent arc is intact Signup and view all the answers

What should you check if the pupil size difference is larger in dim or bright illumination?

The near/accommodative reflex Signup and view all the answers

What is the primary concern in a patient with isolated III CN palsy and pupil involvement?

Ruling out PCA aneurysm Signup and view all the answers

What is the recommended course of action for a patient with pupil-sparing isolated III CN palsy and a history of diabetes or hypertension?

Close monitoring for pupillary involvement Signup and view all the answers

At what age should a patient with pupillary sparing isolated III CN palsy be referred for neurotesting, regardless of underlying medical conditions?

50 years old Signup and view all the answers

What is the typical resolution time for most ischemic causes of isolated III CN palsy?

90 days Signup and view all the answers

What is the recommended follow-up time for a patient with isolated III CN palsy and a history of vascular disease?

5-7 days Signup and view all the answers

What should be suspected in a patient with isolated III CN palsy and a history of giant cell arteritis?

Vascular disease affecting CN III central fibers Signup and view all the answers

In children under 10 years old, what is the recommended course of action for isolated III CN palsy, regardless of pupillary involvement?

Ordering neurotesting immediately Signup and view all the answers

What type of anisocoria is characterized by being equal in dim and bright illumination, without ptosis?

Physiological anisocoria Signup and view all the answers

What is the name of the condition in which the light reflex is absent or abnormal, but the near response is intact?

Argyll Robertson Pupil Signup and view all the answers

Which of the following substances can cause mydriasis of up to 8 mm?

Tropicamide Signup and view all the answers

What is the name of the condition characterized by unilateral or bilateral tonically reacting pupils developing in otherwise healthy patients?

Adie's Tonic Pupil Signup and view all the answers

What is the name of the substance used to treat hemorrhoids and also has a non-clinical use to decrease eye bags?

Phenylephrine Signup and view all the answers

What is the name of the condition caused by an afferent defect, essentially a 'blind eye'?

Amaurotic pupil Signup and view all the answers

What is the purpose of instilling dilute Pilocarpine 0.125% in the eyes?

To diagnose Adie's Tonic Pupil Signup and view all the answers

What is the mechanism of action of apraclonidine in diagnosing Horner's Syndrome?

It acts on the delayed sensitivity of alpha 1 receptors in the dilator muscle. Signup and view all the answers

What is the purpose of pharmacologic diagnostic testing in anisocoria?

To differentiate between physiologic anisocoria and Horner's Syndrome. Signup and view all the answers

What is the characteristic pupillary response in Horner's Syndrome?

Anisocoria with the affected eye being smaller. Signup and view all the answers

What is the purpose of hydroxyamphetamine testing?

To differentiate between central and preganglionic lesions. Signup and view all the answers

What is the most common cause of isolated III CN palsy with pupil involvement?

Posterior communicating artery aneurysm. Signup and view all the answers

What is the mechanism of action of cocaine in diagnosing Horner's Syndrome?

It blocks the reuptake of norepinephrine at the neuroeffector junction. Signup and view all the answers

What is the significance of a negative hydroxyamphetamine test result?

It indicates a postganglionic lesion. Signup and view all the answers