Neuro-Ophthalmology — MCQs

Neuro-Ophthalmology Indian Medical PG Practice Questions and MCQs

Question 101: Which of the following conditions does NOT affect vision?

A. Corneal ulcer
B. Papilloedema (Correct Answer)
C. Optic atrophy
D. Retinal detachment

Explanation: ### Explanation The correct answer is **B. Papilloedema**. **1. Why Papilloedema is the Correct Answer** Papilloedema is defined as passive bilateral disc edema resulting from **increased intracranial pressure (ICP)**. In its early and established stages, visual acuity remains **characteristically normal**. This is a crucial diagnostic differentiator from other forms of disc edema (like papillitis). Vision is only affected in the late/atrophic stage due to secondary optic atrophy or if there is macular involvement (e.g., a macular star or hemorrhage). **2. Why the Other Options are Incorrect** * **A. Corneal Ulcer:** Any breach in the corneal epithelium associated with inflammation/infection causes significant visual impairment due to loss of corneal transparency and irregular astigmatism. * **C. Optic Atrophy:** This represents the end-stage of various optic nerve pathologies, characterized by the degeneration of retinal ganglion cell axons. It leads to permanent and often profound loss of vision. * **D. Retinal Detachment:** The separation of the neurosensory retina from the underlying retinal pigment epithelium (RPE) disrupts the phototransduction process, leading to rapid visual field loss or total blindness if the macula is involved. **3. Clinical Pearls for NEET-PG** * **Early Sign of Papilloedema:** Loss of spontaneous venous pulsations (SVPs) on fundoscopy (though absent in 20% of normal individuals). * **Visual Field Defect:** The most common early field defect in papilloedema is an **enlarged blind spot** (due to peripapillary retinal displacement). * **Foster Kennedy Syndrome:** Ipsilateral optic atrophy (due to direct tumor compression) and contralateral papilloedema (due to raised ICP), typically seen in olfactory groove meningiomas. * **Differentiating Feature:** Unlike optic neuritis, papilloedema does **not** cause a Relative Afferent Pupillary Defect (RAPD) unless it is asymmetrical and advanced.

Question 102: Which nerve carries the motor component of the light reflex?

A. 1st nerve
B. 2nd nerve
C. 3rd nerve (Correct Answer)
D. 4th nerve

Explanation: **Explanation:** The pupillary light reflex is a classic autonomic reflex arc consisting of an afferent (sensory) limb and an efferent (motor) limb. **1. Why the 3rd Nerve is Correct:** The **3rd Cranial Nerve (Oculomotor nerve)** carries the **efferent (motor) component** of the light reflex. Specifically, the parasympathetic fibers originate from the **Edinger-Westphal nucleus** in the midbrain. These fibers travel along the surface of the 3rd nerve to reach the **ciliary ganglion**. From there, postganglionic short ciliary nerves innervate the **sphincter pupillae** muscle, causing pupillary constriction (miosis). **2. Why the Other Options are Incorrect:** * **Option A (1st Nerve):** The Olfactory nerve is responsible for the sense of smell and has no role in ocular reflexes. * **Option B (2nd Nerve):** The Optic nerve carries the **afferent (sensory) component**. It transmits light stimuli from the retina to the pretectal nucleus in the midbrain. Damage here leads to an Afferent Pupillary Defect (RAPD). * **Option C (4th Nerve):** The Trochlear nerve is a pure motor nerve that innervates only the Superior Oblique muscle; it does not carry autonomic fibers for the pupil. **Clinical Pearls for NEET-PG:** * **Consensual Light Reflex:** Occurs because the pretectal nucleus sends fibers to **both** Edinger-Westphal nuclei (via the posterior commissure). * **Surgical vs. Medical 3rd Nerve Palsy:** Parasympathetic fibers are located **superficially** on the 3rd nerve. Therefore, they are easily compressed by an aneurysm (e.g., PCom artery), leading to a **dilated pupil** ("Surgical" palsy). In diabetic "Medical" palsy, the pupil is often spared due to microvascular ischemia affecting only the deep fibers. * **Near Reflex:** Unlike the light reflex, the pathway for the near reflex (accommodation) bypasses the pretectal nucleus.

Question 103: A patient presents with headache and eye complaints. Examination of the right eye reveals a right superotemporal quadrantanopia. Examination of the left eye reveals a left superotemporal quadrantanopia and a left centrocecal scotoma. What is the likely site of the lesion?

A. Left optic nerve and chiasm (Correct Answer)
B. Left optic tract and chiasm
C. Right optic nerve and chiasm
D. Right optic tract and chiasm

Explanation: ### Explanation This clinical presentation describes a **Junctional Scotoma**, a classic neuro-ophthalmological finding localized to the junction of the optic nerve and the optic chiasm. **1. Why Option A is Correct:** The lesion is located at the **posterior aspect of the left optic nerve** where it joins the chiasm. * **Left Centrocecal Scotoma:** This is caused by damage to the left optic nerve fibers (specifically the papillomacular bundle), leading to central vision loss in the ipsilateral (left) eye. * **Right Superotemporal Quadrantanopia:** This occurs because the lesion involves **Wilbrand’s Knee**. These are the inferior nasal fibers from the contralateral (right) eye that decussate in the chiasm and loop anteriorly into the terminal part of the opposite (left) optic nerve before proceeding to the optic tract. Damage to these fibers results in a superior temporal field defect in the opposite eye. **2. Why Other Options are Wrong:** * **Option B (Left Optic Tract):** A tract lesion would cause a contralateral homonymous hemianopia (right-sided), not an ipsilateral scotoma. * **Option C (Right Optic Nerve):** This would cause a right-sided centrocecal scotoma and a left-sided superotemporal defect (the reverse of this case). * **Option D (Right Optic Tract):** This would cause a left-sided homonymous hemianopia. **3. Clinical Pearls for NEET-PG:** * **Wilbrand’s Knee:** High-yield anatomical landmark; inferior nasal fibers loop 4mm into the contralateral optic nerve. * **Junctional Scotoma of Traquair:** A variation where the lesion is slightly more anterior, causing a dense monocular scotoma with only a very subtle contralateral superior temporal defect. * **Common Cause:** Most frequently caused by a **Meningioma** (tuberculum sellae) or a **Pituitary Adenoma** compressing the junction from below. * **Rule of Thumb:** Ipsilateral central loss + Contralateral superior temporal loss = Junctional lesion.

Question 104: In Holmes-Adie pupil, which of the following statements is false?

A. There is absent or retarded pupil reaction to light and near.
B. Most cases are bilateral. (Correct Answer)
C. Causes reduced or absent accommodation.
D. Constricts with 2.5% methacholine.

Explanation: **Explanation:** **Holmes-Adie Pupil (Adie’s Tonic Pupil)** is a clinical condition resulting from post-ganglionic parasympathetic denervation of the **ciliary ganglion**. **1. Why Option B is the correct (False) statement:** In approximately **80% of cases, Holmes-Adie pupil is unilateral**, at least initially. While it may become bilateral over several years (at a rate of 4% per year), the hallmark presentation is a young female with a single dilated pupil. Therefore, stating that "most cases are bilateral" is clinically incorrect. **2. Analysis of other options:** * **Option A (True):** Due to damage to the ciliary ganglion, the pupillary sphincter is denervated. This leads to a **light-near dissociation**, where the reaction to light is absent or very slow (tonic), and the near reflex is also slow/retarded. * **Option C (True):** Since the ciliary ganglion also supplies the ciliary muscle, patients often experience **impaired accommodation**, leading to blurred near vision. * **Option D (True):** This is a classic diagnostic test. Due to **denervation supersensitivity**, the affected pupil constricts significantly when exposed to weak cholinergic agents like **0.125% Pilocarpine** or **2.5% Methacholine**, which would have no effect on a normal pupil. **Clinical Pearls for NEET-PG:** * **Demographics:** Most common in young women (20–40 years). * **Adie’s Syndrome:** The triad of Tonic pupil + Absent/diminished deep tendon reflexes (usually Ankle jerk) + Segmental anhidrosis. * **Slit-lamp finding:** "Vermiform movements" (iris sector palsy) due to irregular contraction of the iris sphincter. * **Mnemonic:** "Adie is a Lady" (Common in females).

Question 105: Optic radiations arise from?

A. Lateral Geniculate body (Correct Answer)
B. Medial Geniculate Body
C. Superior colliculus
D. Inferior colliculus

Explanation: **Explanation:** The visual pathway is a fundamental topic in neuro-ophthalmology. The correct answer is the **Lateral Geniculate Body (LGB)**. **1. Why Lateral Geniculate Body (LGB) is correct:** The LGB, located in the thalamus, serves as the primary relay station for visual information. It receives axons from the retinal ganglion cells via the optic tract. The neurons of the LGB then give rise to the **Geniculocalcarine tract**, commonly known as **Optic Radiations**. These fibers travel through the internal capsule (retrolentiform and sublentiform parts) to reach the primary visual cortex (Brodmann area 17) in the occipital lobe. **2. Why the other options are incorrect:** * **Medial Geniculate Body (MGB):** This is the relay station for the **auditory pathway**, not the visual pathway. (Mnemonic: **M**edial for **M**usic/Hearing). * **Superior Colliculus:** While it receives some visual input, it is primarily involved in mediating **visual reflexes** (like the pupillary light reflex and saccadic eye movements) rather than the conscious perception of vision. * **Inferior Colliculus:** This is a major relay nucleus in the **auditory pathway**, situated below the superior colliculus. **3. Clinical Pearls for NEET-PG:** * **Meyer’s Loop:** The inferior fibers of the optic radiation that loop around the temporal horn of the lateral ventricle. A lesion here causes **"Pie in the sky"** (Superior Homonymous Quadrantanopia). * **Baum’s Loop:** The superior fibers passing through the parietal lobe. A lesion here causes **"Pie on the floor"** (Inferior Homonymous Quadrantanopia). * **Blood Supply:** The optic radiations are supplied by the Middle Cerebral Artery (MCA) and Posterior Cerebral Artery (PCA).

Question 106: Lamina cribrosa is not formed in which of the following conditions?

A. Iris coloboma
B. Nanophthalmia
C. Morning Glory Syndrome (Correct Answer)
D. Optic nerve agenesis

Explanation: **Explanation:** The **Lamina Cribrosa** is a mesh-like structure formed by the multilayered network of collagen fibers from the sclera. It serves as a bridge across the posterior scleral foramen, allowing the exit of optic nerve fibers. **Why Morning Glory Syndrome (MGS) is the correct answer:** Morning Glory Syndrome is a congenital optic disc anomaly characterized by a funnel-shaped excavation of the posterior pole that includes the optic disc. The fundamental embryological defect in MGS is the **failure of the posterior sclera to develop properly**, leading to the **absence of the lamina cribrosa**. Instead, the floor of the excavation is filled with a plug of white glial tissue. This distinguishes it from an optic disc coloboma, where the lamina cribrosa is typically present but defective. **Analysis of Incorrect Options:** * **Iris Coloboma:** This is a defect in the iris resulting from the failure of the embryonic fissure to close. It does not involve the posterior segment or the development of the scleral lamina. * **Nanophthalmia:** This refers to a small but structurally "normal" eye. While the sclera is abnormally thick in nanophthalmia, the lamina cribrosa is present. * **Optic Nerve Agenesis:** This is an extremely rare condition where the optic nerve, retinal ganglion cells, and retinal vessels are absent. While the nerve is missing, the question focuses on the specific structural failure of the scleral bridge seen in MGS. **High-Yield Clinical Pearls for NEET-PG:** * **MGS Appearance:** Large disc, central glial tuft, and **straight, radially arranged retinal vessels** (resembling a "Morning Glory" flower). * **Associations:** MGS is frequently associated with **transsphenoidal basal encephaloceles** and **Moyamoya disease**. Always rule out midline craniofacial defects. * **Visual Prognosis:** Usually poor (legal blindness) and carries a high risk of **serous retinal detachment**.

Question 107: All of the following are true about Optokinetic Nystagmus (OKN) EXCEPT:

A. Jerk nystagmus induced by moving repetitive targets
B. Useful for localising the cause of isolated homonymous hemianopia
C. Slow phase is a pursuit, fast phase is a saccade
D. Type of pathological nystagmus (Correct Answer)

Explanation: **Explanation:** **Optokinetic Nystagmus (OKN)** is a **physiological**, involuntary jerk nystagmus triggered by moving repetitive stimuli across the visual field (e.g., watching telephone poles from a moving train). **Why Option D is the correct answer:** OKN is a **physiological response**, not a pathological one. Its presence indicates an intact visual pathway and oculomotor system. It is used clinically to test visual acuity in infants or malingerers; if OKN can be induced, the patient possesses at least some degree of vision. **Analysis of incorrect options:** * **Option A:** OKN is indeed a **jerk nystagmus**. It occurs when the eyes track a moving object until it disappears from view, then snap back to fixate on the next incoming object. * **Option C:** It consists of two distinct phases: a **slow phase** (smooth pursuit) in the direction of the moving stimulus and a **fast phase** (saccade) in the opposite direction to reset the eyes. * **Option B:** OKN is a vital tool for localizing lesions in **isolated homonymous hemianopia**. * *Occipital lobe lesion:* OKN is usually **symmetrical** (normal). * *Parietal lobe lesion:* OKN is **asymmetrical** (impaired/absent when the drum is rotated toward the side of the lesion). This is known as the "Positive OKN Sign." **Clinical Pearls for NEET-PG:** * **Rule of thumb:** If a patient has homonymous hemianopia + abnormal OKN = **Parietal lobe** involvement. * **Malingering:** OKN is the gold standard for detecting "pseudoblindness." * **Pathway:** The slow phase is mediated by the ipsilateral parieto-occipital cortex; the fast phase is mediated by the contralateral frontal eye fields (FEF).

Question 108: All of the following are true about Adie's pupil EXCEPT:

A. Seen due to inflammation of the ciliary ganglion secondary to post-viral illness.
B. Pupil is supersensitive to pilocarpine.
C. Bilateral constricted and irregular pupil. (Correct Answer)
D. Adie's pupil shows no response to light.

Explanation: ### Explanation **Adie’s Tonic Pupil** is a clinical condition caused by damage to the **postganglionic parasympathetic fibers** (short ciliary nerves) or the **ciliary ganglion**. **Why Option C is the correct answer (The "Except"):** Adie’s pupil is typically **unilateral** (80% of cases) and **dilated** (mydriatic), not constricted. A "bilateral, constricted, and irregular pupil" describes an **Argyll Robertson Pupil** (associated with neurosyphilis), which is the classic differential diagnosis. In Adie's, the pupil is large and regular in shape, though it may show "segmental palsy" on slit-lamp examination. **Analysis of other options:** * **Option A:** The most common etiology is idiopathic inflammation of the ciliary ganglion, often following a **viral prodrome** (e.g., Herpes Zoster). * **Option B:** Due to **denervation supersensitivity**, Adie’s pupil constricts significantly when challenged with **dilute pilocarpine (0.125%)**, whereas a normal pupil will not react to such a low concentration. * **Option C:** This is the hallmark of the condition. There is **Light-Near Dissociation**; the pupil shows a very poor or absent reaction to light but a slow, "tonic" (delayed) contraction to the near stimulus. --- ### High-Yield Clinical Pearls for NEET-PG: * **Holmes-Adie Syndrome:** Adie’s pupil associated with **absent deep tendon reflexes** (usually ankle jerks). * **Demographics:** Most commonly seen in young females (20–40 years). * **Slit-lamp finding:** "Vermiform movements" (worm-like contractions) of the iris sphincter. * **The "3 D's" of Adie's:** **D**ilated pupil, **D**enervation supersensitivity, and **D**elayed (tonic) response to near.

Question 109: What is the characteristic clinical feature of sixth nerve palsy?

A. Convergent squint (Correct Answer)
B. Divergent squint
C. Limitation in upward movement
D. Limitation in downward movement

Explanation: **Explanation:** The **Sixth Cranial Nerve (Abducens nerve)** innervates the **Lateral Rectus (LR)** muscle, which is responsible for the abduction (outward movement) of the eye. 1. **Why Option A is correct:** In sixth nerve palsy, the Lateral Rectus is paralyzed. The **Medial Rectus (MR)**, which is its antagonist, remains unopposed. This results in the eye being pulled medially (inward) toward the nose, leading to an **Esotropia** or **Convergent Squint**. Patients typically present with horizontal diplopia (double vision) that worsens when looking toward the side of the lesion. 2. **Why other options are incorrect:** * **Option B (Divergent Squint):** This is characteristic of **Third Nerve Palsy**. When the Medial Rectus is paralyzed, the Lateral Rectus acts unopposed, pulling the eye outward (Exotropia). * **Options C & D (Limitation in vertical movement):** Vertical eye movements are controlled by the Superior/Inferior Recti and the Oblique muscles (innervated by CN III and CN IV). A pure sixth nerve palsy only affects horizontal abduction. **High-Yield Clinical Pearls for NEET-PG:** * **Longest Intracranial Course:** The Abducens nerve has the longest intracranial course, making it highly susceptible to injury from increased intracranial pressure (**False Localizing Sign**). * **Wernicke-Korsakoff Syndrome:** Often presents with bilateral sixth nerve palsy. * **Gradenigo’s Syndrome:** Characterized by sixth nerve palsy, persistent ear discharge (otitis media), and trigeminal pain (petrositis). * **Compensatory Head Posture:** The patient will turn their face **toward the side of the paralyzed muscle** to minimize diplopia.

Question 110: Painless loss of vision is seen in all conditions listed below, EXCEPT which one?

A. Papilledema
B. Papillitis
C. Central Retinal Artery Occlusion (CRAO)
D. Angle closure glaucoma (Correct Answer)

Explanation: **Explanation:** The key to answering this question lies in differentiating between conditions that cause **painless** versus **painful** vision loss. **Why Angle Closure Glaucoma is the Correct Answer:** Acute Angle Closure Glaucoma (AACG) is a medical emergency characterized by a sudden, severe rise in intraocular pressure (IOP). This rapid rise stretches the corneal lamellae and stimulates the ciliary nerves, leading to **excruciating ocular pain**, headache, nausea, and vomiting. It is a classic cause of **painful** sudden loss of vision. **Analysis of Incorrect Options (Painless Conditions):** * **Papilledema:** This refers to optic disc swelling due to increased intracranial pressure. It is typically bilateral and characterized by a **painless** presentation. Vision is usually preserved in early stages, though transient visual obscurations may occur. * **Papillitis:** This is a form of optic neuritis where the optic disc is involved. While optic neuritis is often associated with pain on eye movement, the visual loss itself is considered "painless" in the sense that there is no surface or deep-seated ache like that found in glaucoma or uveitis. (Note: In many exams, Papillitis is categorized under painless vision loss compared to the intense pain of AACG). * **Central Retinal Artery Occlusion (CRAO):** This is the "stroke of the eye." It presents as a sudden, catastrophic, and **painless** loss of vision, often described as a "curtain coming down." **NEET-PG High-Yield Pearls:** * **Sudden Painless Loss of Vision:** Think CRAO, CRVO, Retinal Detachment, and Vitreous Hemorrhage. * **Sudden Painful Loss of Vision:** Think Acute Angle Closure Glaucoma, Endophthalmitis, and Uveitis. * **Papilledema vs. Papillitis:** Papilledema usually has normal visual acuity (initially) and no RAPD, whereas Papillitis has markedly decreased vision and a positive RAPD.

Practice by Chapter

Anatomy of Visual Pathways

Practice Questions

Pupillary Disorders

Practice Questions

Optic Neuritis

Practice Questions

Ischemic Optic Neuropathies

Practice Questions

Other Optic Neuropathies

Practice Questions

Papilledema

Practice Questions

Cranial Nerve Palsies

Practice Questions

Nystagmus

Practice Questions

Visual Field Defects

Practice Questions

Neuro-ophthalmic Manifestations of Intracranial Lesions

Practice Questions

Functional Visual Disorders

Practice Questions

Migraine and the Eye

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free