NEET-PG 2020 - Ophthalmology PYQs Practice Questions

Q: Esotropia is common in

Hypermetropia. ***Hypermetropia*** - **Esotropia**, or inward turning of the eye, is common in **hypermetropia** (farsightedness) due to the accommodative effort required to focus. - In hypermetropia, **excessive accommodation** is needed to see clearly at all distances, especially for **near vision**. - This constant **accommodative effort** stimulates convergence through the **accommodation-convergence reflex**, predisposing to **accommodative esotropia**, particularly in children. *Myopia* - **Myopia** (nearsightedness) is typically associated with **exotropia** (outward turning of the eye). - This is because myopic individuals exert less accommodative effort for near vision, reducing the stimulus for convergence and potentially leading to divergence of the eyes. *Emmetropia* - **Emmetropia** describes an eye with **no refractive error**, where light focuses perfectly on the retina without accommodation for distance. - Individuals with emmetropia generally have **orthophoria** (proper alignment of the eyes) and are less prone to strabismus like esotropia unless an underlying muscle imbalance is present. *Astigmatism* - **Astigmatism** is an optical defect in which the eye does not focus light evenly onto the retina, causing blurred vision at any distance. - While it can be associated with other refractive errors, **astigmatism itself is not directly or commonly associated with esotropia**. [Practice more Ophthalmology PYQs on OnCourse]

Q: A 65-year-old male with a history of hypertension and diabetes presents to the OPD with complaints of diplopia and squint. On examination, the secondary deviation is more than the primary deviation. Which of the following is the most likely diagnosis?

paralytic squint. ***Paralytic squint*** The key finding of **secondary deviation being greater than primary deviation** is a classic sign of **paralytic strabismus**. This occurs because the paretic eye (due to neurological deficit) has to work harder to fixate, leading to an exaggerated innervation to the yoked muscle in the healthy eye, causing a larger deviation (Hering's law of equal innervation). The patient's age and history of **hypertension and diabetes** increase the risk of **cranial nerve palsies** (e.g., oculomotor, trochlear, abducens), which are common causes of paralytic squint due to microvascular ischemia. *Concomitant strabismus* In **concomitant strabismus**, the degree of deviation remains constant in all directions of gaze, meaning **primary and secondary deviations are equal**. This contradicts the clinical finding in the patient. Concomitant strabismus often presents in childhood and is typically non-paralytic, with no underlying neurological deficit affecting muscle action. *Restrictive strabismus* **Restrictive strabismus** is characterized by physical limitation of eye movement due to mechanical restriction of an extraocular muscle, often seen in conditions like **thyroid eye disease** or **orbital trauma**. While restrictive strabismus can cause diplopia and reduced eye movement, it typically involves a **limited range of motion** and usually does not present with secondary deviation being greater than primary deviation in the same manner as a paralytic squint. *Pseudo strabismus* **Pseudo strabismus** is an apparent misalignment of the eyes where the eyes are actually straight. This can be due to features like a **wide epicanthal fold** or a **small interpupillary distance**. In pseudo strabismus, there is **no true deviation** on cover-uncover testing, and therefore, the concepts of primary and secondary deviation do not apply, nor would there be actual diplopia. [Practice more Ophthalmology PYQs on OnCourse]

Q: The patient presents with unilateral proptosis and bilateral abducent nerve palsy. What is the most likely cause?

Cavernous sinus pathology. The patient presents with unilateral proptosis and bilateral abducent nerve palsy. What is the most likely cause? ***Cavernous sinus pathology*** - **Unilateral proptosis** combined with **bilateral abducens nerve palsy** is a classic presentation consistent with cavernous sinus involvement, as the abducens nerves (CN VI) pass through both cavernous sinuses and are vulnerable to pathology there. [1] - The cavernous sinus contains multiple cranial nerves (**III, IV, V1, V2, VI**) and the internal carotid artery, making it a critical anatomical location where lesions can cause complex neurological deficits affecting orbital structures and eye movements. [1] *Orbital cellulitis* - Typically presents with **unilateral proptosis**, pain, eyelid swelling, and fever, often following a sinus infection. - It primarily affects the **orbital contents anterior to the orbital septum** and would not explain bilateral abducens nerve palsy. *Orbital pseudotumor* - Characterized by **unilateral proptosis**, pain, and diplopia due to idiopathic inflammation of orbital tissues. - While it can cause ophthalmoplegia, **bilateral abducens nerve palsy** is not a typical presentation for a condition usually confined to one orbit. *Orbital lymphoma* - Presents with **painless, slowly progressive unilateral proptosis** or an orbital mass. - While it can cause compressive symptoms, **bilateral abducens nerve palsy** is an atypical presentation as the disease usually remains confined to a single orbit. [Practice more Ophthalmology PYQs on OnCourse]

Q: Incongruous Homonymous hemianopia with Wernicke's hemianopia pupil is seen with the lesion of

Optic tract lesion. ***Optic tract lesion*** - An **optic tract lesion** typically causes **incongruous homonymous hemianopia** because the fibers are not fully segregated by their retinal origin, leading to unequal visual field defects in the two eyes [1]. - The **Wernicke's hemianopic pupil** is a specific sign associated with optic tract lesions involving the afferent pupillary fibers, where direct light reflex is lost in the hemianopic half of the pupil, but consensual reflex is preserved [1]. *Optic radiation lesion* - An optic radiation lesion generally causes **congruous homonymous hemianopia**, as the fibers are more organized by retinal correspondence further along the visual pathway. - It does not typically present with a Wernicke's hemianopic pupil, as the pupillary fibers usually exit the visual pathway before reaching the optic radiations [1]. *Lateral geniculate body lesion* - A lesion of the lateral geniculate body (LGB) would result in a **congruous homonymous hemianopia**, similar to optic radiation lesions, because the fibers are already well-segregated and organized. - The LGB is primarily a relay station for visual information, and a lesion here would not typically affect the pupillary light reflex in the specific way seen in Wernicke's hemianopic pupil [1]. *Anterior occipital cortex lesion* - Lesions in the anterior occipital cortex, particularly the primary visual cortex, typically cause **macular sparing homonymous hemianopia** due to the dual blood supply to the macular representation area [1]. - Such lesions do not involve the afferent pupillary pathways and therefore would not cause a Wernicke's hemianopic pupil. [Practice more Ophthalmology PYQs on OnCourse]

Q: In the context of retinal conditions, what is the primary cause of shifting fluid beneath the retina?

Exudative Retinal detachment. ***Exudative Retinal detachment*** - This condition is characterized by the accumulation of **serous fluid** beneath the retina without a retinal break, causing the retina to detach. The fluid can shift with changes in head position due to gravity, leading to a **"shifting fluid" phenomenon**. - It results from conditions that compromise the **retinal pigment epithelium (RPE)** or choroidal vasculature, such as **choroidal tumors**, **inflammatory diseases**, or **severe hypertension**, leading to leakage of fluid. *Tractional Retinal Detachment* - This type of detachment occurs when **fibrovascular membranes** on the retinal surface contract and pull the neurosensory retina away from the RPE. - The detachment is usually **immobile** or minimally mobile because it is held in place by fibrous adhesions, and therefore, does not typically exhibit shifting fluid. *Rhegmatogenous retinal detachment* - This is the most common type of retinal detachment and occurs due to a **full-thickness break or tear** in the retina, allowing vitreous fluid to pass into the subretinal space. - While fluid is present, the key feature is a retinal break, and the detached retina is typically more fixed by the flow through the break rather than gravitationally shifting. *Retinodialysis* - Retinodialysis is a specific type of **rhegmatogenous retinal detachment** characterized by a **disinsertion of the retina from its ora serrata attachment**, often due to trauma. - Similar to other rhegmatogenous detachments, fluid accumulates in the subretinal space, but the primary cause is the tear/disinsertion, and it doesn't primarily manifest as a shifting fluid characteristic, which is more indicative of exudative causes. [Practice more Ophthalmology PYQs on OnCourse]

Question 1

Esotropia is common in

Accepted Answer

Hypermetropia

Answer

Myopia

Answer

Emmetropia

Answer

Astigmatism

Question 2

A 65-year-old male with a history of hypertension and diabetes presents to the OPD with complaints of diplopia and squint. On examination, the secondary deviation is more than the primary deviation. Which of the following is the most likely diagnosis?

Accepted Answer

paralytic squint

Answer

concomitant strabismus

Answer

restrictive strabismus

Answer

pseudo strabismus

Question 3

The patient presents with unilateral proptosis and bilateral abducent nerve palsy. What is the most likely cause?

Accepted Answer

Cavernous sinus pathology

Answer

Orbital cellulitis

Answer

Orbital pseudotumor

Answer

Orbital lymphoma

Question 4

Incongruous Homonymous hemianopia with Wernicke's hemianopia pupil is seen with the lesion of

Accepted Answer

Optic tract lesion

Answer

Optic radiation lesion

Answer

Lateral geniculate body lesion

Answer

Anterior occipital cortex lesion

Question 5

In the context of retinal conditions, what is the primary cause of shifting fluid beneath the retina?

Accepted Answer

Exudative Retinal detachment

Answer

Tractional Retinal Detachment

Answer

Rhegmatogenous retinal detachment

Answer

Retinodialysis

Question 6

What is the most common cause of sympathetic ophthalmia?

Accepted Answer

Penetrating injury to the eye

Answer

Blunt ocular trauma

Answer

Chemical injury to the eye

Answer

Retinal detachment

Question 7

What is the diagnosis for a patient with unilateral proptosis with bilateral 6th nerve palsy with chemosis and euthyroid status?

Accepted Answer

Cavernous sinus thrombosis

Answer

Retinoblastoma

Answer

Thyroid ophthalmopathy

Answer

Orbital pseudotumour

Question 8

The shifting fluid sign is characteristic of which condition?

Accepted Answer

Exudative retinal detachment

Answer

Retinal hole

Answer

Tractional retinal detachment

Answer

Rhegmatogenous retinal detachment

NEET-PG 2020 — Ophthalmology