Pediatric Ophthalmology and Strabismus — MCQs

A 2-year-old girl presents with deteriorating vision, a whitish hue in the right pupil, strabismus, and ocular pain and tenderness. An ophthalmologist removes a multifocal tumor from the right eye. Pathology reveals rosettes composed of cuboidal-to-columnar cells surrounding a central lumen. What gene mutation on which chromosome is most likely responsible for this condition?

Q129Medium

What is the first step in the management of an 18-month-old child with medial deviation of both eyes?

Q130Easy

What is the commonest manifestation of retinoblastoma?

Pediatric Ophthalmology and Strabismus Indian Medical PG Practice Questions and MCQs

Question 121: A 22-year-old emmetropic male has exotropia in his right eye. What surgical intervention is indicated to correct this to an orthophoric state?

A. Medial rectus recession with convex lens prescription
B. Lateral rectus recession with convex lens prescription
C. Lateral rectus resection without glasses
D. Lateral rectus recession without glasses (Correct Answer)

Explanation: **Explanation:** The patient presents with **Exotropia** (outward deviation of the eye). To correct this surgically, the goal is to either weaken the "pull" of the lateral muscle or strengthen the "pull" of the medial muscle. 1. **Why Option D is correct:** A **Lateral Rectus (LR) recession** is a weakening procedure where the muscle is detached and reattached further back on the globe. This reduces its outward pull, allowing the eye to return to an orthophoric (straight) position. Since the patient is **emmetropic** (normal refractive state), no corrective glasses (convex or concave) are required post-surgery. 2. **Why the other options are incorrect:** * **Option A:** Medial rectus recession would weaken the inward pull, worsening the exotropia. Convex lenses are used for accommodative esotropia, not exotropia. * **Option B:** While LR recession is correct, **convex lenses** (plus lenses) relax accommodation and can actually worsen an exotropia by decreasing accommodative convergence. * **Option C:** **Resection** is a strengthening procedure. Resecting the Lateral Rectus would pull the eye further outward, severely aggravating the exotropia. **High-Yield Clinical Pearls for NEET-PG:** * **Rule of Thumb:** To correct a deviation, **Recess** (weaken) the muscle in the direction of the deviation or **Resect** (strengthen) the muscle opposite to the deviation. * **Exotropia Surgery:** Standard approach is Bilateral LR Recession or Unilateral LR Recession + Medial Rectus Resection (R&R). * **Refraction & Squint:** Hypermetropia is associated with Esotropia (due to over-accommodation); Myopia is often associated with Exotropia. * **Prism Base:** Exotropia is measured/corrected with a **Base-In (BI)** prism.

Question 122: Which of the following clinical signs is NOT typically observed in a patient with superior oblique palsy?

A. Abnormal head posture
B. Facial asymmetry
C. Diplopia
D. Ptosis (Correct Answer)

Explanation: Superior oblique palsy (4th Cranial Nerve Palsy) is the most common cause of isolated vertical muscle palsy. To understand why **Ptosis** is the correct answer, we must look at the anatomy and clinical presentation of the Trochlear nerve. ### Why Ptosis is NOT observed: Ptosis (drooping of the upper eyelid) is caused by dysfunction of the **Levator Palpebrae Superioris (LPS)** or Müller’s muscle. The LPS is innervated by the **Oculomotor nerve (CN III)**. Superior oblique palsy involves the **Trochlear nerve (CN IV)**, which exclusively supplies the superior oblique muscle. Therefore, ptosis is a feature of CN III palsy or Horner’s syndrome, not CN IV palsy. ### Explanation of Incorrect Options: * **Abnormal head posture:** Patients typically present with a **compensatory head tilt** to the opposite side of the lesion (Bielschowsky's sign) to minimize vertical and torsional diplopia. * **Facial asymmetry:** In congenital cases, long-standing head tilt leads to remodeling of facial bones, resulting in hemi-facial microsomia (the face on the side of the tilt appears smaller). * **Diplopia:** Patients experience **vertical and torsional diplopia**, which worsens on downgaze and adduction (e.g., while reading or walking down stairs). ### High-Yield Clinical Pearls for NEET-PG: * **Park’s Three-Step Test:** The gold standard for diagnosing isolated cyclovertical muscle palsy (like SO palsy). * **Bielschowsky Head Tilt Test:** Forced head tilt to the affected side increases the vertical deviation (hypertropia). * **Most common cause:** Trauma (acquired) or congenital. * **Action of SO:** Primary action is **Incyclotorsion**; secondary is Depression; tertiary is Abduction. (Mnemonic: **SIN** - **S**uperior muscles are **In**vertors).

Question 123: Which of the following is FALSE regarding incomitant squint?

A. It is the most common type of squint in adults.
B. Paralysis of an extraocular muscle is often present.
C. Restricted ocular movements are typically observed.
D. The primary deviation is equal to the secondary deviation. (Correct Answer)

Explanation: In incomitant squint (paralytic or restrictive), the angle of deviation varies with the direction of gaze and the eye used for fixation. **Explanation of the Correct Answer:** **Option D is FALSE** because in incomitant squint, the **secondary deviation is always greater than the primary deviation**. This is based on **Desmarres’ Law** (derived from Hering’s Law of equal innervation). When the paretic eye fixates (secondary deviation), the brain sends excessive nervous impulse to the weak muscle to move it; according to Hering’s Law, an equal amount of increased innervation is sent to the yoke muscle of the sound eye, causing it to overact and produce a larger deviation. In contrast, primary and secondary deviations are equal only in **comitant (non-paralytic) squint**. **Analysis of Incorrect Options:** * **Option A:** True. Incomitant squints (due to trauma, vascular issues like diabetes, or tumors) are the most common type of squint seen in adults, whereas comitant squints are more common in children. * **Option B:** True. Paralysis or paresis of one or more extraocular muscles (e.g., 6th nerve palsy) is the hallmark of paralytic incomitant squint. * **Option C:** True. Limitation of ocular movement in the field of action of the paralyzed muscle is a characteristic clinical finding. **High-Yield Clinical Pearls for NEET-PG:** * **Primary Deviation:** Deviation of the affected eye when the normal eye fixates. * **Secondary Deviation:** Deviation of the normal eye when the affected eye fixates. * **Diplopia:** Incomitant squints typically present with binocular diplopia, which is maximal in the field of action of the paralyzed muscle. * **Compensatory Head Posture:** Patients often adopt a head tilt or face turn to minimize diplopia and maintain binocular single vision.

Question 124: Which of the following statements is NOT true about retinoblastoma?

A. Bilateral in 20-30% of cases
B. Affects the age group of 1-5 years
C. More common in males (Correct Answer)
D. Leukocoria is the earliest symptom

Explanation: **Explanation:** Retinoblastoma is the most common primary intraocular malignancy of childhood, arising from the neurosensory retina. **Why Option C is the correct answer (The False Statement):** Retinoblastoma shows **no gender or racial predilection**. It affects males and females equally. Therefore, the statement that it is "more common in males" is incorrect. **Analysis of other options:** * **Option A (Bilateral in 20-30%):** This is a true statement. Approximately 25-30% of cases are bilateral and are typically associated with germline mutations in the *RB1* gene on chromosome 13q14. * **Option B (Age group 1-5 years):** This is true. Most cases are diagnosed before the age of 5. Bilateral cases usually present earlier (average 12 months), while unilateral cases present slightly later (average 24 months). * **Option D (Leukocoria is the earliest symptom):** This is true. **Leukocoria** (white pupillary reflex or "amaurotic cat's eye reflex") is the most common presenting sign (60%), followed by **strabismus** (20%). **High-Yield Clinical Pearls for NEET-PG:** * **Genetics:** Follows Knudson’s "Two-hit hypothesis." * **Pathology:** Characterized by **Flexner-Wintersteiner rosettes** (highly specific), Homer-Wright rosettes, and fleurettes. * **Calcification:** Dystrophic calcification is a hallmark; it is seen on CT scans and helps differentiate it from Coats' disease. * **Classification:** The International Classification for Intraocular Retinoblastoma (ICIR) is used to guide management (Groups A to E). * **Trilateral Retinoblastoma:** Bilateral retinoblastoma associated with a pineal gland tumor (pineoblastoma).

Question 125: Which of the following accurately describes amblyopia?

A. Color blindness
B. Myopia
C. Any deviation from the normal function of the eye (Correct Answer)
D. Strabismus

Explanation: **Explanation:** **Amblyopia**, commonly known as "lazy eye," is defined as a unilateral or bilateral reduction in best-corrected visual acuity (BCVA) that cannot be attributed directly to the effect of any structural abnormality of the eye. It occurs due to abnormal visual experience during the **critical period** of visual development (birth to age 7–8 years). **Why the correct answer is right:** Option C is the most accurate description in this context because amblyopia represents a **functional deficit** rather than a structural one. It is a failure of the brain to process inputs from one eye, leading to a deviation from normal visual function (specifically, a loss of spatial resolution and contrast sensitivity) despite the eye appearing anatomically normal. **Why the other options are wrong:** * **A. Color blindness:** This is a genetic or acquired deficiency in cone photoreceptors, not a developmental visual processing disorder. * **B. Myopia:** This is a refractive error (anatomic/optical) where light focuses in front of the retina. While high myopia can *cause* amblyopia (anisometropic amblyopia), it is not the definition of it. * **D. Strabismus:** This refers to the misalignment of the eyes. While strabismus is a leading *cause* of amblyopia (strabismic amblyopia), the two terms are not synonymous. **High-Yield Clinical Pearls for NEET-PG:** * **Types of Amblyopia:** 1. Strabismic (most common), 2. Anisometropic (difference in refractive error), 3. Stimulus Deprivation (e.g., congenital cataract/ptosis—most severe). * **Treatment:** The mainstay is **occlusion therapy** (patching the "good" eye) or pharmacologic penalization (atropine drops in the good eye) to force the brain to use the amblyopic eye. * **Critical Period:** Treatment is most effective before age 7. Beyond age 10–12, visual plasticity decreases significantly, making reversal difficult.

Question 126: Worth's four-dot test is done for assessing which of the following?

A. Cornea
B. Intraocular pressure
C. Refractive errors
D. Binocular vision (Correct Answer)

Explanation: **Explanation:** The **Worth’s Four-Dot Test (W4DT)** is a clinical test used to assess **Binocular Single Vision (BSV)**, specifically to detect suppression, diplopia, and the presence of fusion. **Why the correct answer is right:** The test utilizes **dissociation** through red-green goggles (red lens over the right eye, green over the left). The patient views a box with four lights: one red, two green, and one white. * **Normal BSV:** The patient sees four dots (the white dot is fused by both eyes). * **Suppression:** The patient sees only two red dots (left eye suppressed) or three green dots (right eye suppressed). * **Diplopia:** The patient sees five dots (failure of fusion). It is a high-yield tool for evaluating sensory status in patients with strabismus. **Why incorrect options are wrong:** * **Cornea:** Evaluated via Slit-lamp biomicroscopy, Placido’s disc, or Keratometry. * **Intraocular Pressure (IOP):** Measured via Tonometry (e.g., Goldmann Applanation Tonometry, Schiotz tonometry). * **Refractive Errors:** Assessed via Retinoscopy or Automated Refractometry. **High-Yield Clinical Pearls for NEET-PG:** * **Distance vs. Near:** W4DT at 6 meters tests the **macular** (central) area; at 33 cm, it tests the **peripheral** retinal area. * **Anomalous Retinal Correspondence (ARC):** A patient with a manifest squint who still sees four dots likely has ARC. * **Bagolini Striated Glasses:** These are considered more "physiological" than W4DT because they do not dissociate the eyes as strongly.

Question 127: What type of squint is typically seen with a 6th cranial nerve palsy?

A. Crossed diplopia
B. Uncrossed diplopia (Correct Answer)
C. Vertical diplopia
D. No diplopia

Explanation: ### Explanation **1. Why Uncrossed Diplopia is Correct:** The 6th cranial nerve (Abducens) innervates the **Lateral Rectus (LR)** muscle, which is responsible for abduction. In a 6th nerve palsy, the LR is paralyzed, leading to an unopposed action of the Medial Rectus. This results in an **Esotropia** (inward deviation of the eye) or a **convergent squint**. In esotropia, the image of an object falls on the nasal retina of the deviated eye. Since the brain projects images from the nasal retina to the temporal visual field, the false image appears on the same side as the affected eye. This is known as **Uncrossed (Homonymous) Diplopia**. **2. Analysis of Incorrect Options:** * **A. Crossed Diplopia:** This occurs in **Exotropia** (divergent squint), typically seen in **3rd cranial nerve palsy**. Here, the image falls on the temporal retina and is projected to the nasal visual field (opposite side). * **C. Vertical Diplopia:** This is characteristic of vertical muscle imbalances, most commonly seen in **4th cranial nerve (Trochlear) palsy** due to Superior Oblique paralysis. * **D. No Diplopia:** This occurs in long-standing childhood strabismus where the brain develops **suppression** to avoid double vision. Acute nerve palsies in adults almost always present with distressing diplopia. **3. Clinical Pearls for NEET-PG:** * **Compensatory Head Posture:** Patients with 6th nerve palsy turn their face **towards the side of the lesion** to maintain binocular single vision. * **Diplopia Character:** The separation of images increases on **lateral gaze** toward the affected side and at a distance. * **Most Common Cause:** In adults, microvascular ischemia (Diabetes/Hypertension) is the most common cause; in children, it may follow a viral infection or indicate a pontine tumor (Glioma). * **Mnemonic:** **E**sotropia = **U**ncrossed (**E-U**); **E**xotropia = **C**rossed (**E-C**).

Question 128: A 2-year-old girl presents with deteriorating vision, a whitish hue in the right pupil, strabismus, and ocular pain and tenderness. An ophthalmologist removes a multifocal tumor from the right eye. Pathology reveals rosettes composed of cuboidal-to-columnar cells surrounding a central lumen. What gene mutation on which chromosome is most likely responsible for this condition?

A. Chromosome 5
B. Chromosome 7
C. Chromosome 9
D. Chromosome 13 (Correct Answer)

Explanation: ### Explanation The clinical presentation of a 2-year-old with **leukocoria** (whitish pupillary reflex), strabismus, and a multifocal intraocular tumor is classic for **Retinoblastoma**, the most common primary intraocular malignancy of childhood. **1. Why Chromosome 13 is Correct:** Retinoblastoma is caused by a mutation in the **RB1 gene**, located on **Chromosome 13 (specifically 13q14)**. This gene is a tumor suppressor that regulates the cell cycle (G1 to S phase transition). According to **Knudson’s "two-hit" hypothesis**, both alleles of the RB1 gene must be inactivated for the tumor to develop. The pathology description of "rosettes surrounding a central lumen" refers to **Flexner-Wintersteiner rosettes**, which are pathognomonic for retinoblastoma and represent photoreceptor differentiation. **2. Why Other Options are Incorrect:** * **Chromosome 5:** Associated with Familial Adenomatous Polyposis (APC gene). * **Chromosome 7:** Associated with Cystic Fibrosis (CFTR gene) and Williams syndrome. * **Chromosome 9:** Associated with Tuberous Sclerosis (TSC1 gene) and Friedreich’s ataxia. **3. Clinical Pearls for NEET-PG:** * **Most common sign:** Leukocoria (60%), followed by Strabismus (20%). * **Pathology:** * **Flexner-Wintersteiner rosettes:** Specific for Retinoblastoma (lumen contains hyaluronic acid). * **Homer Wright rosettes:** Non-specific (also seen in neuroblastoma/medulloblastoma); no central lumen. * **Calcification:** Dystrophic calcification is a hallmark feature seen on CT scans (helps differentiate from Coats' disease). * **Trilateral Retinoblastoma:** Bilateral retinoblastoma associated with a pineal gland tumor (Pineoblastoma). * **Inheritance:** 40% are heritable (germline mutation, often bilateral/multifocal); 60% are sporadic (somatic mutation, usually unilateral). [1]

Question 129: What is the first step in the management of an 18-month-old child with medial deviation of both eyes?

A. Forced ductions test
B. Examination under anesthesia
C. Refractive error testing (Correct Answer)
D. Examination of the fundus

Explanation: In pediatric ophthalmology, the management of strabismus (squint) follows a strict, logical hierarchy. For an 18-month-old presenting with medial deviation (esotropia), the priority is to rule out and treat any underlying refractive or organic causes before considering surgical intervention. **Why Refractive Error Testing is the Correct First Step:** The most common cause of acquired esotropia in children is **Accommodative Esotropia**. This occurs due to uncorrected hypermetropia (farsightedness). To see clearly, the child over-accommodates, which triggers the near reflex (accommodation-convergence-miosis), leading to excessive convergence and medial deviation. The first step is always a **cycloplegic refraction** (using atropine or cyclopentolate) to determine the full refractive error. In many cases, prescribing the correct glasses fully corrects the deviation, making surgery unnecessary. **Why Other Options are Incorrect:** * **Forced Duction Test (FDT):** This is used to differentiate between a paretic muscle (nerve palsy) and a restrictive pathology (e.g., Duane syndrome). It is usually performed intraoperatively or under sedation and is not an initial diagnostic step. * **Examination Under Anesthesia (EUA):** This is reserved for cases where a thorough clinical exam is impossible or when intraocular surgery is planned. It is not a primary diagnostic tool for simple esotropia. * **Examination of the Fundus:** While essential to rule out organic causes like retinoblastoma or macular scars (sensory esotropia), it is performed *after* or as part of the initial clinical assessment, but refractive correction remains the management priority for the deviation itself. **Clinical Pearls for NEET-PG:** * **Golden Rule:** In any child with squint, the first two steps are **Cycloplegic Refraction** and **Fundus Examination** to rule out sensory causes. * **Atropine (1%)** is the cycloplegic of choice for children under 5 years old. * **Pseudostrabismus:** Always rule this out by checking the **Hirschberg corneal reflex**; in pseudo-esotropia (due to epicanthal folds), the reflex is central in both eyes.

Question 130: What is the commonest manifestation of retinoblastoma?

A. Pseudohypopyon
B. Leukocoria (Correct Answer)
C. Squint
D. Nystagmus

Explanation: **Explanation:** **Retinoblastoma** is the most common primary intraocular malignancy of childhood. Understanding its clinical presentation is crucial for early diagnosis and life-saving intervention. **1. Why Leukocoria is the correct answer:** **Leukocoria (white pupillary reflex)** is the most common presenting sign, occurring in approximately **60% of cases**. It is caused by the tumor mass behind the lens reflecting light back through the pupil, replacing the normal red reflex. It is often first noticed by parents in photographs or dim lighting. **2. Analysis of Incorrect Options:** * **B. Squint (Strabismus):** This is the **second most common** manifestation (approx. 20%). It occurs when the tumor involves the macula, leading to loss of central vision and subsequent sensory deviation of the eye. * **A. Pseudohypopyon:** This is a rare, late-stage presentation seen in the diffuse infiltrating variety of retinoblastoma. It occurs when tumor cells settle in the anterior chamber, mimicking an inflammatory hypopyon. * **D. Nystagmus:** This is uncommon and typically only occurs if there is bilateral macular involvement leading to poor fixation from early infancy. **Clinical Pearls for NEET-PG:** * **Most common sign:** Leukocoria (60%). * **Second most common sign:** Strabismus (20%). * **Genetics:** Mutation in the **RB1 gene** on chromosome **13q14**. * **Pathognomonic sign:** Calcification within the tumor (seen on USG or CT scan). * **Histopathology:** Look for **Flexner-Wintersteiner rosettes** (highly specific). * **Most common distant metastasis:** Bone marrow; however, the most common route of spread is via the **optic nerve** to the CNS.

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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