Pediatric Ophthalmology and Strabismus — MCQs

Pediatric Ophthalmology and Strabismus Indian Medical PG Practice Questions and MCQs

Question 81: Which of the following is a feature of concomitant squint?

A. Constant amount of deviation in all directions of gaze (Correct Answer)
B. Associated limitation of ocular movements
C. Different amount of deviation in different directions of gaze
D. Develops in patients at 15-20 years of age

Explanation: ### Explanation **Concomitant (Non-paralytic) Squint** is a type of strabismus where the angle of deviation remains the same (constant) regardless of the direction of gaze or the eye used for fixation. #### Why Option A is Correct: The hallmark of concomitant squint is that the extraocular muscles function normally, but the eyes are not aligned. Because there is no mechanical restriction or muscle paralysis, the degree of misalignment does not change as the eyes move into different positions. This is known as a **constant angle of deviation**. #### Why the Other Options are Incorrect: * **Option B:** Limitation of ocular movements is a characteristic of **paralytic (incomitant) squint**, where a specific nerve or muscle is dysfunctional. In concomitant squint, full range of motion is preserved in both eyes. * **Option C:** A deviation that varies in different directions of gaze is the definition of **incomitant squint**. This occurs when a paretic muscle fails to move the eye into its field of action, increasing the deviation in that direction. * **Option D:** Concomitant squint typically develops in **early childhood** (usually before age 6), during the critical period of visual development. Onset at 15–20 years is rare and usually suggests a paralytic or sensory cause. --- ### High-Yield Clinical Pearls for NEET-PG: * **Primary vs. Secondary Deviation:** In concomitant squint, the primary deviation (normal eye fixing) equals the secondary deviation (squinting eye fixing). In paralytic squint, **Secondary Deviation > Primary Deviation**. * **Sensory Adaptation:** Children with concomitant squint often develop **suppression** or **amblyopia** to avoid diplopia. Diplopia is rare in concomitant squint but common in adult-onset paralytic squint. * **Common Causes:** Refractive errors (especially hypermetropia in accommodative esotropia) and imbalances in the vergence system. * **Synoptophore:** Used to measure the angle of deviation and assess binocular single vision (BSV).

Question 82: Persistent Primary Hyperplastic Vitreous (PHPV) is associated with which condition?

A. Patau syndrome (Correct Answer)
B. Edward syndrome
C. Trisomy 14
D. Down syndrome

Explanation: **Explanation:** **Persistent Primary Hyperplastic Vitreous (PHPV)**, now more commonly termed **Persistent Fetal Vasculature (PFV)**, is a congenital anomaly resulting from the failure of the primary vitreous and hyaloid vascular system to regress during embryogenesis. **Why Patau Syndrome is Correct:** **Patau Syndrome (Trisomy 13)** is the chromosomal anomaly most strongly associated with PHPV. It is characterized by severe midline defects and ocular malformations. In these patients, PHPV often presents as a retrolental mass (leukocoria) in a microphthalmic eye. The association is a high-yield fact because Trisomy 13 is the most common systemic condition linked to bilateral cases of PHPV. **Analysis of Incorrect Options:** * **Edward Syndrome (Trisomy 18):** While it presents with systemic anomalies like clenched fists and rocker-bottom feet, its primary ocular associations are corneal opacities and congenital glaucoma, not typically PHPV. * **Trisomy 14:** This is a rare chromosomal disorder. While it can involve ocular features like microphthalmia, it is not classically associated with PHPV in medical literature or examinations. * **Down Syndrome (Trisomy 21):** Ocular hallmarks include Brushfield spots, epicanthal folds, keratoconus, and early-onset cataracts. PHPV is not a feature of Down syndrome. **Clinical Pearls for NEET-PG:** * **Laterality:** PHPV is typically **unilateral** (90% of cases). If it is **bilateral**, always suspect **Patau Syndrome**. * **Clinical Triad:** Microphthalmos, Leukocoria (white pupillary reflex), and elongated ciliary processes. * **Differential Diagnosis:** PHPV is a major differential for Retinoblastoma. Unlike Retinoblastoma, PHPV presents with a **smaller eye (microphthalmos)** and lacks calcification on ultrasound/CT. * **Complications:** Can lead to secondary angle-closure glaucoma due to the swelling of the lens or traction on the iris.

Question 83: What percentage of retinoblastomas are bilateral?

A. 10%
B. 20%
C. 30% (Correct Answer)
D. 50%

Explanation: **Explanation:** Retinoblastoma is the most common primary intraocular malignancy of childhood. Its occurrence is governed by **Knudson’s "Two-Hit" Hypothesis**, which explains the distribution between unilateral and bilateral cases. **1. Why 30% is Correct:** Approximately **25–30%** of retinoblastoma cases are **bilateral**. These cases are almost always **hereditary**, meaning the child has a germline mutation in the *RB1* gene (the "first hit" is present in every cell of the body). Because every retinal cell carries this mutation, there is a high probability that both eyes will undergo a "second hit," leading to bilateral multifocal tumors. **2. Analysis of Incorrect Options:** * **A (10%) & B (20%):** These percentages are too low. While hereditary cases make up about 40% of all cases, not all hereditary cases present bilaterally at the same time; however, the established clinical average for bilateral presentation remains 30%. * **D (50%):** This is too high. The majority of cases (**70%**) are **unilateral**. Most unilateral cases are sporadic (non-hereditary), where both "hits" occur locally within a single retinal cell. **3. High-Yield Clinical Pearls for NEET-PG:** * **Genetics:** *RB1* gene is located on **Chromosome 13q14**. * **Most Common Sign:** **Leukocoria** (Amaurotic cat’s eye reflex), followed by strabismus. * **Pathology:** Look for **Flexner-Wintersteiner rosettes** (highly specific) and Homer-Wright rosettes. * **Calcification:** Intraocular calcification in a child under 3 years is retinoblastoma until proven otherwise (visible on CT/Ultrasound). * **Trilateral Retinoblastoma:** Bilateral retinoblastoma associated with a pinealoblastoma (pineal gland tumor). * **Risk:** Patients with the germline mutation (bilateral cases) have a high risk of secondary non-ocular malignancies, most commonly **Osteosarcoma**.

Question 84: Pseudoconvergent squint is seen with which of the following conditions?

A. Thyrotoxicosis
B. Broad epicanthus (Correct Answer)
C. Abducent squint
D. Narrow interpupillary distance

Explanation: **Explanation:** **Pseudostrabismus (Apparent Squint)** is a clinical condition where the eyes appear misaligned (crossed or divergent) despite being orthophoric (perfectly aligned) on objective testing, such as the Hirschberg corneal reflex test and the cover-uncover test. **Why Broad Epicanthus is Correct:** **Pseudoconvergent squint (Pseudoesotropia)** is most commonly caused by a **broad epicanthal fold**. This is a vertical fold of skin extending from the upper eyelid to the side of the nose, covering the inner canthus. Because less of the nasal sclera (white of the eye) is visible, the eyes appear to be turned inward, especially when the child looks to either side. Other causes include a flat nasal bridge and a narrow interpupillary distance (IPD). **Analysis of Incorrect Options:** * **Thyrotoxicosis:** Typically associated with **Pseudoexophthalmos** (due to lid retraction) rather than a pseudoconvergent squint. * **Abducent Squint:** This refers to a 6th nerve palsy, which results in a **true esotropia** (convergent squint), not a pseudo-squint. * **Narrow Interpupillary Distance:** While a narrow IPD can cause pseudoesotropia, **Broad Epicanthus** is the classic and most frequent cause cited in exams. (Note: Option D is a potential cause, but B is the definitive clinical hallmark). **High-Yield Clinical Pearls for NEET-PG:** * **Pseudoesotropia:** Caused by broad epicanthus, flat nasal bridge, or narrow IPD. * **Pseudoexotropia:** Caused by a wide IPD (hypertelorism) or a large positive Angle Kappa. * **Diagnostic Test:** The **Hirschberg test** will show a central corneal light reflex in both eyes in cases of pseudo-squint, distinguishing it from true strabismus. * **Angle Kappa:** A large **negative** angle kappa can mimic esotropia; a large **positive** angle kappa (common in high hypermetropia) mimics exotropia.

Question 85: A patient has right lateral rectus palsy. Towards which side will his head be deviated?

A. Towards right (Correct Answer)
B. Towards left
C. Upwards
D. Downwards

Explanation: **Explanation:** In paralytic strabismus, a patient adopts a compensatory head posture to minimize **diplopia** (double vision) and maintain binocular single vision. The fundamental principle is that the **face turns in the direction of the action of the paralyzed muscle.** 1. **Why Option A is Correct:** The Right Lateral Rectus (RLR) is an abductor; its primary action is to move the right eye outward (towards the right). In RLR palsy, the eye deviates inward (esotropia) due to the unopposed action of the medial rectus. To compensate, the patient turns their **face towards the right**. This rotation of the head shifts the object of interest into the "field of comfort" (the left hemifield relative to the right eye), where the paralyzed muscle is not required to act, thereby neutralizing the diplopia. 2. **Why Other Options are Incorrect:** * **Option B (Towards Left):** Turning the head to the left would require the right eye to abduct further to maintain fixation, which would significantly worsen the diplopia and the deviation. * **Options C & D (Upwards/Downwards):** Vertical head tilts are characteristic of vertical muscle palsies (e.g., Superior Oblique or Superior Rectus) or A/V patterns, not isolated horizontal rectus palsies. **Clinical Pearls for NEET-PG:** * **Rule of Thumb:** The face always turns towards the **direction of the paralyzed muscle's action**. * **Diplopia:** In LR palsy, the diplopia is **uncrossed (homonymous)** and is maximal on attempted abduction of the affected eye. * **Nerve Involved:** LR is supplied by the **6th Cranial Nerve (Abducens)**. * **Differential:** In Superior Oblique (4th Nerve) palsy, the patient presents with a **head tilt to the opposite shoulder** (Bielschowsky's test) to compensate for the loss of intorsion.

Question 86: In 'A'-esotropia, how does the amount of deviation change with vertical gaze?

A. Increases in upward gaze and decreases in downward gaze (Correct Answer)
B. Decreases in upward gaze and increases in downward gaze
C. Increases in upward as well as downward gaze
D. Decreases in upward as well as downward gaze

Explanation: **Explanation:** In pediatric ophthalmology, **Alphabet Patterns** refer to horizontally manifest strabismus that changes in magnitude depending on the vertical position of the gaze. **1. Why Option A is Correct:** 'A'-pattern esotropia is defined by a horizontal deviation that is **more convergent (increased esotropia) in upward gaze** and **less convergent (decreased esotropia) in downward gaze**. By convention, a difference of **10 prism diopters (PD)** or more between the two gazes is clinically significant for an 'A' pattern. This is frequently associated with **superior oblique overaction**, which causes an abducting effect in downgaze, thereby reducing the esotropia as the eyes move down. **2. Why Other Options are Incorrect:** * **Option B:** This describes **'V'-pattern esotropia**, where the deviation is greater in downward gaze and lesser in upward gaze (often associated with inferior oblique overaction). * **Options C & D:** These do not follow the "Alphabet" morphology. A deviation that increases or decreases in both vertical directions would suggest a different complex motility disorder or a restrictive pathology rather than a standard A or V pattern. **3. High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic:** Think of the shape of the letter. In **'A'**, the top is narrow (more ET/less XT) and the bottom is wide (less ET/more XT). In **'V'**, the top is wide and the bottom is narrow. * **Significance:** 'A' patterns are often associated with **Superior Oblique Overaction**, while 'V' patterns are associated with **Inferior Oblique Overaction**. * **Surgical Rule:** For 'A' patterns, the **Mnemonic "MILS"** (Medial In-Lateral Super) is used: move the Medial Rectus **U**pward or the Lateral Rectus **D**ownward to collapse the pattern.

Question 87: Which of the following is not a feature of congenital esotropia?

A. Onset before 6 months
B. Cross fixation
C. Inferior oblique overaction
D. Surgery rarely required (Correct Answer)

Explanation: **Explanation:** Congenital (Infantile) Esotropia is a large-angle inward deviation of the eyes that occurs early in life. The correct answer is **D (Surgery rarely required)** because surgery is actually the **mainstay of treatment**. Since the deviation is usually large (>30 prism diopters) and constant, it rarely resolves spontaneously. Early surgical intervention (usually bilateral medial rectus recession) is required, ideally before age 2, to promote the development of binocular single vision. **Analysis of other options:** * **A. Onset before 6 months:** By definition, infantile esotropia manifests within the first six months of life. If it occurs after 6 months, it is classified as acquired esotropia. * **B. Cross fixation:** This is a hallmark feature where the child uses the left eye to look at the right visual field and the right eye to look at the left visual field. This often eliminates the need for abduction, sometimes mimicking a pseudo-abducens nerve palsy. * **C. Inferior oblique overaction (IOOA):** This is a common associated finding, typically appearing after age 1 or 2. It results in elevation of the eye when it moves toward the nose (in adduction). **Clinical Pearls for NEET-PG:** * **Dissociated Vertical Deviation (DVD):** A classic association where the non-fixing eye drifts upward and outward. * **Latent Nystagmus:** Nystagmus that appears or worsens when one eye is covered. * **Refractive Error:** Usually normal for the child's age (mild hypermetropia); unlike accommodative esotropia, it is not corrected by glasses. * **Ciancia Syndrome:** A subtype characterized by large-angle esotropia, cross-fixation, and latent nystagmus.

Question 88: Which of the following findings is most consistent with accommodative esotropia?

A. Dissociated vertical deviation
B. Onset from infancy to 4 years of age (Correct Answer)
C. Hypermetropia of 8.00 D
D. Poor to no binocular potential

Explanation: **Explanation:** **Accommodative Esotropia** is a common form of childhood strabismus caused by an overactive accommodative reflex. When a child with uncorrected hypermetropia (farsightedness) attempts to focus on an object, the excessive accommodation triggers an associated over-convergence (the AC/A ratio), leading to an inward deviation of the eyes. 1. **Why Option B is Correct:** The typical onset of accommodative esotropia is between **6 months and 7 years**, with a peak incidence between **2 and 4 years**. This coincides with the age when children begin to develop finer near-vision tasks and their accommodative system becomes more active. 2. **Why Incorrect Options are Wrong:** * **Option A:** Dissociated Vertical Deviation (DVD) is a hallmark of **Infantile (Congenital) Esotropia**, not accommodative esotropia. * **Option C:** While hypermetropia is the cause, it is typically in the range of **+2.00 to +6.00 D**. High hypermetropia (>+8.00 D) often results in blurred vision that the child cannot overcome, leading to a *lack* of accommodative effort and, consequently, no esotropia. * **Option D:** Unlike infantile esotropia, children with accommodative esotropia usually have **excellent binocular potential** if the deviation is corrected early with spectacles, as the eyes were straight during early infancy. **High-Yield Clinical Pearls for NEET-PG:** * **Treatment of Choice:** Full cycloplegic refraction and prescription of the **maximum plus power** glasses. * **AC/A Ratio:** High AC/A ratio esotropia is a subtype where the deviation is significantly greater at near than at distance. * **Amblyopia:** If the esotropia is not fully corrected or is monocular, it can lead to refractive or strabismic amblyopia.

Question 89: Which of the following is NOT a presentation of retinoblastoma?

A. Leucocoria
B. Squint
C. Cataract (Correct Answer)
D. Glaucoma

Explanation: **Explanation:** Retinoblastoma is the most common primary intraocular malignancy of childhood. Understanding its clinical presentation is crucial for NEET-PG, as early diagnosis is life-saving. **Why Cataract is the Correct Answer:** Cataract is **not** a typical presentation of retinoblastoma. In fact, the presence of a clear lens is a key clinical feature that helps differentiate retinoblastoma from other causes of "white eye" (pseudogliomas) like Persistent Fetal Vasculature (PFV) or congenital cataracts. While advanced tumors may rarely cause secondary lens changes due to inflammation or metabolic disturbances, it is not a primary or diagnostic presentation. **Analysis of Incorrect Options:** * **Leucocoria (A):** This is the **most common** presentation (60%). It refers to a white pupillary reflex caused by the tumor mass behind the lens. * **Squint/Strabismus (B):** This is the **second most common** presentation (20%). It occurs when the tumor involves the macula, leading to loss of central vision and subsequent sensory deviation of the eye. * **Glaucoma (D):** Secondary glaucoma is a known complication. It can occur due to neovascularization of the iris (NVI), anterior displacement of the iris-lens diaphragm by a large endophytic tumor, or tumor cells blocking the trabecular meshwork. **Clinical Pearls for NEET-PG:** * **Most common sign:** Leucocoria (Cat’s eye reflex). * **Inheritance:** Most cases are sporadic; however, heritable cases (40%) are due to a germline mutation in the **RB1 gene (Chromosome 13q14)** and are often bilateral. * **Pathognomonic Histology:** **Flexner-Wintersteiner rosettes** (highly specific). * **Calcification:** Intraocular calcification in a child under 3 years is retinoblastoma until proven otherwise (detected via B-scan USG or CT). * **Most common distant metastasis:** Bone marrow.

Question 90: What is to be done for congenital cataract involving the visual axis?

A. Wait and watch
B. Operate when the baby reaches an appropriate age
C. Mydriatics are given
D. Operate immediately (Correct Answer)

Explanation: **Explanation:** The primary goal in managing congenital cataracts is the prevention of **stimulus-deprivation amblyopia**. When a cataract involves the visual axis (central and dense), it prevents a clear image from forming on the retina during the "critical period" of visual development. **1. Why "Operate Immediately" is correct:** Visual development is most rapid in the first few months of life. If the visual axis is obstructed, the brain permanently loses the ability to process images from that eye. To ensure the best visual prognosis, surgery is recommended as soon as possible—ideally within **4 to 6 weeks** for unilateral cataracts and **6 to 8 weeks** for bilateral cataracts. **2. Why the other options are incorrect:** * **Wait and watch / Appropriate age:** Delaying surgery leads to irreversible amblyopia and nystagmus. Unlike senile cataracts, "waiting for maturity" is contraindicated in pediatrics. * **Mydriatics:** While dilating drops can sometimes be used as a temporary measure for small, central zonular cataracts to allow light to pass around the opacity, they are not a definitive treatment for cataracts involving the visual axis. **Clinical Pearls for NEET-PG:** * **Surgical Technique:** The standard procedure is **Lens Aspiration + Posterior Capsulotomy + Anterior Vitrectomy**. This is because the posterior capsule opacifies rapidly in children. * **IOL Implantation:** Generally avoided in infants under 6 months to 1 year due to changing eye size and inflammatory response; contact lenses or aphakic glasses are used initially. * **Most common cause:** Most bilateral cases are idiopathic, but the most common infectious cause is **Congenital Rubella Syndrome** (look for "pearly white" cataract).

Practice by Chapter

Amblyopia

Practice Questions

Esotropia

Practice Questions

Exotropia

Practice Questions

Vertical Deviations

Practice Questions

Special Forms of Strabismus

Practice Questions

Nystagmus in Children

Practice Questions

Pediatric Cataract

Practice Questions

Retinopathy of Prematurity

Practice Questions

Pediatric Glaucoma

Practice Questions

Pediatric Neuro-ophthalmology

Practice Questions

Genetic Eye Diseases in Children

Practice Questions

Pediatric Ocular Trauma

Practice Questions

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