A 17-year-old boy with chronic foul-smelling discharge from the right ear for years has fever, headache and vomiting. MRI shows a ring-enhancing abscess in the right temporal lobe. On perimetry, which field defect is most likely?

Left upper homonymous quadrantanopia

Left lower homonymous quadrantanopia

Bitemporal upper quadrantanopia

Right upper homonymous quadrantanopia

A 47-year-old woman comes to casualty with the worst headache of her life over the last two days and a drooping left eyelid. The left eye is turned down and out, cannot be moved up, down or in, and the left pupil is 7 mm and does not react to light. What is the most appropriate first investigation?

Fasting blood glucose and HbA1c

Neuro-ophthalmology, squint and visual pathway

18 NEET-PG practice questions on Neuro-ophthalmology, squint and visual pathway, part of Ophthalmology. The first 18 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Easy
A 44-year-old bank clerk keeps bumping into people on both sides while walking through crowded stations. Confrontation testing shows loss of the outer half of the field in each eye, and MRI shows a sellar mass rising upwards. Where along the visual pathway are the affected fibres being compressed?
1. AOptic radiation
2. BOptic tract
3. CLateral geniculate body
4. DOptic chiasm
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Answer: D · Optic chiasm
A pituitary macroadenoma growing upwards presses on the optic chiasm from below, where the nasal retinal fibres of both eyes cross. Nasal fibres carry the temporal fields, so the result is a bitemporal hemianopia, often starting in the upper temporal quadrants because the lower crossing fibres are hit first. Lesions behind the chiasm give homonymous defects instead. Formal perimetry is used to document the defect and follow it after treatment.
- A: Optic radiation lesions give homonymous hemianopia or quadrantanopia.
- B: An optic tract lesion gives an incongruous homonymous hemianopia, not a bitemporal one.
- C: A lateral geniculate lesion also gives a homonymous defect.
Question 2 · Easy
A 58-year-old man has shooting pains in his legs and an unsteady gait that worsens in the dark; Romberg sign is positive. Both pupils are small and irregular and do not constrict to bright light. How are his pupils expected to respond when he looks at a near target?
1. AThey constrict, then dilate
2. BThey constrict briskly
3. CThey dilate widely
4. DThey stay fixed and small
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Answer: B · They constrict briskly
Small, irregular pupils that do not react to light but constrict on near effort (light-near dissociation) are Argyll Robertson pupils, classically seen in neurosyphilis, here with tabes dorsalis. The lesion is thought to lie in the rostral midbrain, interrupting the light reflex fibres to the Edinger-Westphal nucleus while sparing the more ventral near-response pathway. The patient should have serological tests for syphilis and CSF examination. A similar dissociation can occur in diabetes.
- A: Constriction followed by escape and dilation describes an afferent defect on light testing, not the near response.
- C: Dilation on near effort is not a recognised response.
- D: Fixed pupils to both light and near suggest a third nerve or pharmacological cause, not Argyll Robertson pupils.
Question 3 · Medium
A 17-year-old boy with chronic foul-smelling discharge from the right ear for years has fever, headache and vomiting. MRI shows a ring-enhancing abscess in the right temporal lobe. On perimetry, which field defect is most likely?
1. ALeft lower homonymous quadrantanopia
2. BLeft upper homonymous quadrantanopia
3. CBitemporal upper quadrantanopia
4. DRight upper homonymous quadrantanopia
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Answer: B · Left upper homonymous quadrantanopia
Unsafe chronic otitis media can spread to the temporal lobe and form an abscess. The lower fibres of the optic radiation (Meyer's loop), carrying the upper visual field, sweep forward through the temporal lobe. A right temporal lesion therefore causes a left (contralateral) superior homonymous quadrantanopia, the 'pie in the sky' defect. Parietal lesions affect the upper fibres and give an inferior quadrantanopia.
- A: A lower quadrantanopia comes from a parietal lesion of the upper radiation fibres.
- C: Bitemporal defects come from the chiasm, not the temporal lobe.
- D: The defect is contralateral to the lesion, not on the same side.
Question 4 · Medium
A 6-year-old girl is seen in a district hospital eye OPD. Consider four statements about amblyopia: 1. Occluding the better eye is the main treatment. 2. Atropine drops in the better eye can be used instead of a patch. 3. A dense congenital cataract left untreated causes the most severe type. 4. Acuity in the amblyopic eye improves fully when it is tested through a pinhole. Which statements are correct?
1. A1 and 2 only
2. B1, 2 and 3 only
3. C1, 3 and 4 only
4. D1, 2, 3 and 4
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Answer: B · 1, 2 and 3 only
Statements 1, 2 and 3 are correct. Amblyopia is treated by correcting any refractive error and then making the brain use the weak eye, by occluding the better eye or by blurring it with atropine (penalisation). Stimulus deprivation, as from a dense congenital cataract or ptosis covering the pupil, causes the deepest amblyopia, so such cataracts need surgery within the first weeks to months of life. Statement 4 is false: a pinhole improves blur from refractive error, but amblyopia is a cortical deficit and does not improve with a pinhole.
- A: Omits deprivation amblyopia from congenital cataract, which is the most severe type.
- C: Includes the pinhole claim, which is false, and omits atropine penalisation.
- D: Includes the pinhole claim; a pinhole does not correct amblyopia.
Question 5 · Medium
A 47-year-old woman comes to casualty with the worst headache of her life over the last two days and a drooping left eyelid. The left eye is turned down and out, cannot be moved up, down or in, and the left pupil is 7 mm and does not react to light. What is the most appropriate first investigation?
1. AFasting blood glucose and HbA1c
2. BThyroid function tests
3. CCT angiography of the brain
4. DTensilon test for myasthenia
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Answer: C · CT angiography of the brain
A painful third nerve palsy with a dilated pupil suggests compression, most often by an aneurysm of the posterior communicating artery. The pupillomotor fibres run on the outer surface of the nerve, so compressing lesions involve the pupil early. A ruptured or expanding aneurysm can kill, so urgent vascular imaging (CT or MR angiography, with catheter angiography if needed) comes first. Microvascular palsies of diabetes typically spare the pupil.
- A: Diabetic microvascular palsy usually spares the pupil; the dilated pupil here demands vascular imaging.
- B: Thyroid eye disease causes restrictive myopathy and proptosis, not a pupil-involving third nerve palsy.
- D: Myasthenia never affects the pupil.
Question 6 · Medium
A 24-year-old motorcyclist is reviewed in the OPD three weeks after a head injury. He has vertical double vision that is worst when reading or walking down stairs, and he keeps his head tilted towards his left shoulder. Which muscle is paralysed?
1. ALeft superior oblique
2. BRight inferior rectus
3. CRight superior oblique
4. DLeft inferior oblique
Answer and explanation in LearnFree account
Question 7 · Medium
A 56-year-old man who has smoked bidis for 35 years has pain in the right shoulder radiating to the ulnar side of the forearm. The right upper lid droops by 2 mm, the right pupil is smaller than the left in dim light, and the right side of his face does not sweat. What is the most appropriate next investigation?
1. AMRI of the lumbar spine
2. BTensilon test for myasthenia
3. CCarotid Doppler of the left side
4. DCT of the chest including the lung apex
Answer and explanation in LearnFree account
Question 8 · Easy
A 5-year-old girl fails a school vision screening. Cycloplegic refraction shows +4.5 D in the right eye and +0.5 D in the left, with no squint. After three months of full spectacle correction, best-corrected acuity is still 6/24 in the right eye and 6/6 in the left. What is the next step in treatment?
1. APatch the right eye for part of each day
2. BPatch the left eye for part of each day
3. CRefer for refractive laser surgery
4. DWait for vision to improve with age
Answer and explanation in LearnFree account
Question 9 · Medium
A 27-year-old woman with BMI 34 kg/m² has daily headaches, brief blurring of vision on bending and horizontal double vision. Both optic discs are swollen with normal acuity. MRI and MR venography are normal, and lumbar puncture shows an opening pressure of 34 cm of CSF with normal CSF contents. Which drug is the first-line treatment along with weight loss?
1. AMannitol
2. BTimolol
3. CAcetazolamide
4. DPrednisolone
Answer and explanation in LearnFree account
Question 10 · Hard
A 31-year-old woman has lost vision in the left eye over a week. In the swinging flashlight test, both pupils constrict when the right eye is lit and both dilate when the light swings to the left eye. The resident notes: 1. The lesion lies in the left optic nerve. 2. The left pupil is larger than the right in ordinary room light. 3. Lighting the right eye makes the left pupil constrict normally. 4. A dense cataract in the left eye could produce this sign. Which statements are correct?
1. A2 and 4 only
2. B1 and 3 only
3. C1, 3 and 4 only
4. D1, 2 and 3 only
Answer and explanation in LearnFree account
Question 11 · Hard
A 25-year-old woman complains of double vision when looking to the right. On right gaze, her left eye does not move inward past the midline and her right eye shows jerky nystagmus as it moves outward. Both eyes converge normally when she looks at a near pen. Where is the lesion?
1. ALeft oculomotor nerve
2. BRight paramedian pontine reticular formation
3. CLeft medial longitudinal fasciculus
4. DRight medial longitudinal fasciculus
Answer and explanation in LearnFree account
Question 12 · Easy
A 26-year-old woman has blurred vision in the right eye for four days with pain on moving the eye. Visual acuity is 6/36 in the right eye, colour vision is reduced and the fundus looks normal. Which bedside test best detects the pupil sign expected in this patient?
1. ASwinging flashlight test
2. BNear reflex testing
3. CCover-uncover test
4. DPinhole acuity test
Answer and explanation in LearnFree account
Question 13 · Medium
A 7-year-old boy has had morning headaches and vomiting for a month and now sees double when looking across the room. His right eye turns in and cannot move outward beyond the midline; both discs are swollen. MRI shows a mass in the posterior fossa with hydrocephalus. Why has he developed the eye movement problem?
1. AStretching of the long sixth nerve by raised pressure
2. BCompression of the fourth nerve in the cavernous sinus
3. CSpread of the tumour into the right orbit
4. DDirect invasion of the third nerve nucleus
Answer and explanation in LearnFree account
Question 14 · Medium
A 66-year-old man with atrial fibrillation who stopped his anticoagulant notices that he misses objects on his right side. Perimetry shows a right homonymous hemianopia with sparing of central vision. Reading and visual acuity are normal, and there is no limb weakness. Which artery is most likely occluded?
1. ARight posterior cerebral artery
2. BLeft anterior cerebral artery
3. CLeft posterior cerebral artery
4. DLeft middle cerebral artery
Answer and explanation in LearnFree account
Question 15 · Medium
A 4-year-old boy is brought because his family thinks one eye turns in. In the cover test, the examiner covers the left eye while the child looks at a toy; the uncovered right eye moves outward to take up fixation. Covering the right eye produces no movement of the left eye. What does this indicate?
1. ARight exotropia
2. BRight esotropia
3. CLeft esotropia
4. DPseudo-esotropia
Answer and explanation in LearnFree account
Question 16 · Hard
A 32-year-old woman has not had a period for 8 months and has milky nipple discharge. She also bumps into door frames. Perimetry shows a bitemporal hemianopia, MRI shows a 2.4 cm sellar mass pressing on the chiasm, and serum prolactin is 2,600 ng/mL (reference below 25). What is the best first-line treatment?
1. ARadiotherapy to the sella
2. BOral cabergoline
3. COctreotide injections
4. DTranssphenoidal surgery
Answer and explanation in LearnFree account
Question 17 · Hard
A 21-year-old man squeezed a boil on the side of his nose a week ago. He now has high fever, severe headache, swelling of both upper lids, proptosis and chemosis that began in the right eye and spread to the left. Which cranial nerve is usually the first to be affected in this condition?
1. ATrochlear nerve
2. BAbducens nerve
3. COculomotor nerve
4. DOptic nerve
Answer and explanation in LearnFree account
Question 18 · Medium
A 29-year-old software engineer has had painful, blurred vision in the left eye for five days. Acuity is 6/60, colour vision is poor, there is a left relative afferent pupillary defect and the disc looks normal. Two years ago she had tingling in both legs that settled on its own. Which investigation will best guide her long-term management?
1. ACT scan of the orbits
2. BFundus fluorescein angiography
3. CMRI brain with gadolinium
4. DVisual evoked potentials alone
Answer and explanation in LearnFree account

Neuro-ophthalmology, squint and visual pathway

A 44-year-old bank clerk keeps bumping into people on both sides while walking through crowded stations. Confrontation testing shows loss of the outer half of the field in each eye, and MRI shows a sellar mass rising upwards. Where along the visual pathway are the affected fibres being compressed?

A 58-year-old man has shooting pains in his legs and an unsteady gait that worsens in the dark; Romberg sign is positive. Both pupils are small and irregular and do not constrict to bright light. How are his pupils expected to respond when he looks at a near target?

A 17-year-old boy with chronic foul-smelling discharge from the right ear for years has fever, headache and vomiting. MRI shows a ring-enhancing abscess in the right temporal lobe. On perimetry, which field defect is most likely?

A 47-year-old woman comes to casualty with the worst headache of her life over the last two days and a drooping left eyelid. The left eye is turned down and out, cannot be moved up, down or in, and the left pupil is 7 mm and does not react to light. What is the most appropriate first investigation?

A 24-year-old motorcyclist is reviewed in the OPD three weeks after a head injury. He has vertical double vision that is worst when reading or walking down stairs, and he keeps his head tilted towards his left shoulder. Which muscle is paralysed?

A 25-year-old woman complains of double vision when looking to the right. On right gaze, her left eye does not move inward past the midline and her right eye shows jerky nystagmus as it moves outward. Both eyes converge normally when she looks at a near pen. Where is the lesion?

A 26-year-old woman has blurred vision in the right eye for four days with pain on moving the eye. Visual acuity is 6/36 in the right eye, colour vision is reduced and the fundus looks normal. Which bedside test best detects the pupil sign expected in this patient?

A 21-year-old man squeezed a boil on the side of his nose a week ago. He now has high fever, severe headache, swelling of both upper lids, proptosis and chemosis that began in the right eye and spread to the left. Which cranial nerve is usually the first to be affected in this condition?