Pediatric Ophthalmology and Strabismus — MCQs

Pediatric Ophthalmology and Strabismus Indian Medical PG Practice Questions and MCQs

Question 171: Bilateral proptosis in children is the most common presentation of which condition?

A. Neurofibromatosis
B. Leukemia (Correct Answer)
C. Cavernous hemangioma
D. Malignant fibrous histiocytoma

Explanation: **Explanation:** **Leukemia** (specifically Acute Myeloid Leukemia) is the most common cause of **bilateral proptosis** in children. The orbital involvement typically manifests as a **Granulocytic Sarcoma** (also known as Chloroma), which is a solid tumor composed of primitive granulocytic precursor cells. It often precedes or occurs simultaneously with systemic bone marrow involvement. The proptosis is usually rapid in onset and can be accompanied by ecchymosis of the eyelids. **Analysis of Incorrect Options:** * **Neurofibromatosis (NF-1):** While associated with orbital tumors like optic nerve gliomas or sphenoid wing dysplasia (causing pulsating proptosis), these are typically unilateral rather than bilateral. * **Cavernous Hemangioma:** This is the most common benign orbital tumor in **adults**, not children. It typically presents as a slow, progressive, unilateral proptosis. * **Malignant Fibrous Histiocytoma:** This is an extremely rare mesenchymal tumor in the pediatric age group; it generally presents as a localized, unilateral mass. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of Unilateral Proptosis in children:** Orbital Cellulitis (Inflammatory) or Rhabdomyosarcoma (Neoplastic). * **Most common cause of Bilateral Proptosis in children:** Leukemia (Chloroma) or Neuroblastoma (metastatic). * **Most common cause of Unilateral/Bilateral Proptosis in adults:** Thyroid Eye Disease (Graves' Ophthalmopathy). * **Rhabdomyosarcoma:** The most common *primary* malignant orbital tumor in children (usually unilateral). * **Neuroblastoma:** Often presents with "Raccoon eyes" (periorbital ecchymosis) due to orbital metastasis.

Question 172: All of the following are true for retinoblastoma except?

A. Leucocoria is the most common presentation
B. Always unilateral (Correct Answer)
C. May have family history
D. Most common age group affected is 1-2 years

Explanation: **Explanation:** Retinoblastoma is the most common primary intraocular malignancy of childhood. The statement **"Always unilateral"** is incorrect because approximately **25-30% of cases are bilateral**. **Why Option B is the correct answer (False statement):** Retinoblastoma can be either sporadic or heritable. While the majority (60%) are unilateral and sporadic, cases involving a germline mutation in the **RB1 gene** (located on chromosome 13q14) typically present with **bilateral** or multifocal tumors. Therefore, it is not "always" unilateral. **Analysis of other options:** * **Option A:** **Leucocoria** (white pupillary reflex) is indeed the most common presenting sign (approx. 60%), followed by strabismus. * **Option C:** About 6-10% of cases have a positive **family history**. These are usually autosomal dominant with high penetrance. * **Option D:** The average age of diagnosis is **18 months**. Most cases are diagnosed before the age of 3, making the 1-2 year age group the most common. **High-Yield Clinical Pearls for NEET-PG:** * **Knudson’s Two-Hit Hypothesis:** Explains the genetic basis (two mutations required). * **Pathology:** Look for **Flexner-Wintersteiner rosettes** (highly specific) and Homer-Wright rosettes. * **Diagnosis:** Primarily clinical and via **B-scan Ultrasound** (shows calcification). CT/MRI are used to check for optic nerve involvement or "Trilateral Retinoblastoma" (bilateral RB + Pinealoblastoma). * **Calcification:** Intraocular calcification in a child under 3 years is Retinoblastoma until proven otherwise.

Question 173: A 10-year-old boy presents with bilateral chronic uveitis. Which investigation should be ordered?

A. Hemogram
B. X-ray of sacroiliac joint
C. HIV test
D. Mantoux test (Correct Answer)

Explanation: **Explanation:** In the Indian subcontinent, **Tuberculosis (TB)** remains one of the most common causes of chronic, granulomatous uveitis in children. When a pediatric patient presents with bilateral chronic uveitis, the primary goal is to rule out systemic infectious and inflammatory etiologies. The **Mantoux test** (Tuberculin Skin Test) is a mandatory screening tool in this context to evaluate for latent or active tuberculosis, which can manifest ocularly even in the absence of pulmonary symptoms. **Analysis of Options:** * **Option D (Mantoux Test):** Correct. TB is a leading cause of chronic uveitis in endemic regions. A positive result, combined with clinical findings (like mutton-fat keratic precipitates or choroidal tubercles), strongly suggests ocular TB. * **Option A (Hemogram):** While a baseline investigation, a routine hemogram is non-specific and rarely provides a definitive diagnosis for the etiology of chronic uveitis. * **Option B (X-ray Sacroiliac Joint):** This is the investigation of choice for **Ankylosing Spondylitis**. While associated with uveitis, it typically presents as *acute recurrent unilateral* anterior uveitis in young adults (HLA-B27 associated), rather than chronic bilateral uveitis in a 10-year-old. * **Option C (HIV Test):** While HIV can lead to opportunistic ocular infections (like CMV retinitis), it is not the first-line investigation for a standard presentation of chronic uveitis in a child unless specific risk factors or suggestive clinical signs are present. **High-Yield Clinical Pearls for NEET-PG:** 1. **Most common cause of pediatric uveitis:** Juvenile Idiopathic Arthritis (JIA). Note that JIA-associated uveitis is typically **non-granulomatous** and asymptomatic (white eye). 2. **Granulomatous Uveitis:** Always think of "STELS" — **S**yphilis, **T**uberculosis, **E**ndophthalmitis (fungal), **L**eprosy, and **S**arcoidosis. 3. In any case of chronic uveitis in India, the "Big Three" investigations are **Mantoux test, Chest X-ray, and ACE levels** (to rule out TB and Sarcoidosis).

Question 174: True about paralytic squint is:

A. Uniocular diplopia
B. Binocular diplopia (Correct Answer)
C. The person cannot use the two eyes together
D. Diminished visual acuity

Explanation: **Explanation:** **1. Why Binocular Diplopia is Correct:** Paralytic squint occurs due to the paralysis of one or more extraocular muscles (cranial nerves III, IV, or VI). This leads to a misalignment of the visual axes. When the patient looks in the direction of the paralyzed muscle, the image of an object falls on the fovea of the fixing eye but on a non-foveal (peripheral) retinal point in the deviated eye. This results in the perception of two images from a single object. Since this occurs only when **both eyes are open**, it is termed **binocular diplopia**. It characteristically disappears when one eye is covered. **2. Why Other Options are Incorrect:** * **Option A (Uniocular diplopia):** This is seen when a single eye perceives two images, usually due to optical issues like subluxated lens, polycoria, or incipient cataract. It does not disappear upon covering the other eye. * **Option C (Cannot use two eyes together):** This is incorrect because patients with paralytic squint *can* often use their eyes together in certain positions of gaze (the field of least deviation) or by adopting a compensatory head posture to maintain binocular single vision. * **Option D (Diminished visual acuity):** Paralytic squint is a motor nerve/muscle issue and does not inherently cause a loss of vision. Unlike concomitant squint in children, paralytic squint usually occurs in adults, so **amblyopia** (lazy eye) is rare. **Clinical Pearls for NEET-PG:** * **Secondary Deviation > Primary Deviation:** In paralytic squint, the deviation of the sound eye (when the paralyzed eye fixes) is greater than the deviation of the paralyzed eye (when the sound eye fixes). * **False Projection (Past-pointing):** The patient points beyond the object in the direction of the paralyzed muscle. * **Compensatory Head Posture:** Patients tilt or turn their head toward the action of the paralyzed muscle to minimize diplopia.

Question 175: Regarding amblyopia, which of the following is true?

A. It is a reversible loss of vision.
B. It is associated with squint.
C. It is a defect in refractive error.
D. All of the above. (Correct Answer)

Explanation: **Explanation:** Amblyopia, commonly known as "lazy eye," is defined as a unilateral or bilateral reduction in best-corrected visual acuity (BCVA) that occurs in the absence of any detectable organic pathology of the eye. It results from abnormal visual experience during the **critical period** of visual development (birth to age 7–8 years). **Why Option D is Correct:** * **Reversible loss of vision (Option A):** Amblyopia is unique because it is functional, not structural. If detected and treated early (within the critical period) using methods like patching (occlusion therapy) or atropine penalization, the vision loss can be reversed. * **Associated with squint (Option B):** **Strabismic amblyopia** is one of the most common types. When the eyes are misaligned, the brain suppresses the image from the deviated eye to avoid diplopia (double vision), leading to amblyopia in that eye. * **Defect in refractive error (Option C):** **Anisometropic amblyopia** occurs when there is a significant difference in refractive error between the two eyes. The brain favors the clearer image from the less ametropic eye, leading to "disuse" of the other. **High-Yield Clinical Pearls for NEET-PG:** 1. **Types of Amblyopia:** Strabismic (most common), Anisometropic, Isoametropic (high bilateral refractive error), and Stimulus Deprivation (e.g., congenital cataract—the most severe form). 2. **Crowding Phenomenon:** Amblyopic patients find it easier to read isolated letters than a row of letters. 3. **Treatment:** The mainstay is **occlusion of the sound (better) eye** to force the brain to use the amblyopic eye. 4. **Eccentric Fixation:** A common finding in long-standing strabismic amblyopia where the patient uses a non-foveal point for fixation.

Question 176: What is the typical pupil size of a newborn?

A. Dilated
B. Mid-dilated
C. Constricted (Correct Answer)
D. Normal

Explanation: **Explanation:** The correct answer is **Constricted (C)**. **Medical Concept:** In newborns, the pupils are typically small (miotic) and constricted, usually measuring around **2 mm** in diameter. This physiological miosis is primarily attributed to the **immaturity of the sympathetic nervous system**, which is responsible for pupillary dilation (mydriasis). While the parasympathetic system (responsible for constriction) is relatively functional at birth, the sympathetic innervation to the iris dilator muscle takes several weeks to months to fully develop. Additionally, newborns spend a significant amount of time sleeping or in a state of drowsiness, which further promotes pupillary constriction. **Analysis of Incorrect Options:** * **A & B (Dilated/Mid-dilated):** These states require active sympathetic stimulation or a lack of parasympathetic tone. In a healthy newborn, the lack of sympathetic maturity makes a dilated or mid-dilated pupil abnormal. If present, it may indicate neurological distress, pharmacological influence, or congenital anomalies. * **D (Normal):** While "normal" is subjective, in clinical ophthalmology, the "normal" adult pupil size (3–4 mm in room light) is significantly larger than that of a newborn. Therefore, "constricted" is the more specific and accurate clinical description for this age group. **High-Yield Clinical Pearls for NEET-PG:** * **Pupillary Growth:** The pupil size gradually increases during the first decade of life as the sympathetic system matures and the eye grows. * **Light Reflex:** Although the pupils are small, the **pupillary light reflex** is usually present by **31 weeks of gestation**, though it may be sluggish until closer to term. * **Anisocoria:** A slight difference in pupil size (up to 1 mm) can be physiological, but persistent or large-scale anisocoria in a neonate warrants investigation for Horner’s Syndrome or neurological trauma. * **Mydriatics in Neonates:** Due to the small pupil size and systemic sensitivity, dilute concentrations of phenylephrine (2.5%) and cyclopentolate (0.5%) are used for screening for Retinopathy of Prematurity (ROP).

Question 177: Which of the following tumors can present with a white reflex in the pupil?

A. Squamous cell carcinoma
B. Neurofibroma
C. Retinoblastoma (Correct Answer)
D. Keratoacanthoma

Explanation: **Explanation:** The clinical presentation of a white reflex in the pupil is known as **Leukocoria**. This occurs when an intraocular mass or opacity reflects light back through the pupil instead of the normal red reflex from the vascular choroid. **1. Why Retinoblastoma is correct:** Retinoblastoma is the most common primary intraocular malignancy of childhood. It arises from the neurosensory retina. As the tumor grows (endophytic or exophytic), it forms a creamy-white, vascularized mass within the eye. This mass reflects the light of an ophthalmoscope, resulting in **leukocoria**, which is the most common presenting sign (60% of cases), followed by strabismus. **2. Why the other options are incorrect:** * **Squamous cell carcinoma (SCC):** In the ocular context, this typically affects the conjunctiva or eyelids (surface structures). It presents as a fleshy growth or ulcer, not an intraocular mass causing leukocoria. * **Neurofibroma:** These are benign nerve sheath tumors. While associated with Neurofibromatosis Type 1 (which features Lisch nodules on the iris), they do not typically form large intraocular masses that obscure the red reflex. * **Keratoacanthoma:** This is a fast-growing, low-grade skin tumor (often on the eyelid) characterized by a central keratinous plug. It is an external adnexal lesion and cannot cause a pupillary reflex change. **Clinical Pearls for NEET-PG:** * **Differential Diagnosis of Leukocoria:** Retinoblastoma (most common life-threatening cause), Congenital Cataract (most common overall cause), Coats’ disease, Persistent Fetal Vasculature (PFV), and Retinopathy of Prematurity (ROP). * **Calcification:** The presence of intraocular calcification on CT/Ultrasound is highly suggestive of Retinoblastoma (Dystrophic calcification). * **Flexner-Wintersteiner Rosettes:** These are pathognomonic histological features of Retinoblastoma.

Question 178: What is the treatment for a small retinoblastoma tumor?

A. Enucleation
B. Eviceration
C. Brachytherapy (Correct Answer)
D. Chemotherapy

Explanation: **Explanation:** The management of Retinoblastoma (RB) has shifted from life-saving enucleation to **eye-salvage treatments**, depending on the tumor's size, location, and staging (ICRB classification). **Why Brachytherapy is correct:** For **small, localized tumors** (typically <12 mm in diameter and <6 mm in thickness) that are not involving the optic disc or fovea, **local destructive therapy** is the treatment of choice. Brachytherapy (plaque radiotherapy using Iodine-125 or Ruthenium-106) allows for the delivery of high-dose radiation directly to the tumor site while sparing surrounding healthy ocular tissues. Other focal options for small tumors include cryotherapy (for anterior tumors) and transpupillary thermotherapy (TTT). **Analysis of Incorrect Options:** * **Enucleation:** This is the treatment of choice for **large, advanced tumors** (Group E) where there is no hope for vision, or if there is involvement of the optic nerve, glaucoma, or anterior chamber spread. * **Evisceration:** This is **strictly contraindicated** in suspected intraocular malignancies like retinoblastoma, as it risks extraocular seeding of malignant cells. * **Chemotherapy:** While systemic chemotherapy (Chemoreduction) is used to shrink medium-to-large tumors (Groups B, C, and D) to make them amenable to focal therapy, it is generally not the primary standalone treatment for a very small, isolated tumor that can be cured with local plaque radiotherapy. **High-Yield Clinical Pearls for NEET-PG:** * **Most common intraocular tumor of childhood:** Retinoblastoma. * **Most common presenting sign:** Leukocoria (White pupillary reflex), followed by strabismus. * **Pathognomonic Histology:** Flexner-Wintersteiner rosettes. * **Calcification:** Present in 90% of cases (visible on CT/Ultrasound); a key diagnostic feature. * **Gene:** RB1 gene on Chromosome 13q14.

Question 179: Secondary deviation is more than primary deviation is a feature of?

A. Accommodative squint
B. Paralytic squint (Correct Answer)
C. Infantile esotropia
D. Alternate exotropia

Explanation: ### Explanation The correct answer is **B. Paralytic squint**. #### 1. Why Paralytic Squint is Correct The hallmark of paralytic (incomitant) strabismus is that the **secondary deviation is greater than the primary deviation**. This phenomenon is explained by **Hering’s Law of Equal Innervation**, which states that motor innervation to the yoke muscles of both eyes is always equal and simultaneous. * **Primary Deviation:** Measured when the normal eye fixes. The amount of innervation required is normal. * **Secondary Deviation:** Measured when the paretic (affected) eye fixes. Because the paretic muscle is weak, the brain sends a **massive increase in innervation** to move the paretic eye into position. According to Hering’s Law, this excessive innervation is also sent to the yoke muscle of the healthy eye, causing it to overact significantly. #### 2. Why Other Options are Incorrect * **A, C, & D (Non-paralytic/Concomitant Squints):** In accommodative squint, infantile esotropia, and alternate exotropia, the angle of deviation remains constant regardless of which eye is fixing or the direction of gaze. In these cases, **primary deviation equals secondary deviation**. #### 3. High-Yield Clinical Pearls for NEET-PG * **Hering’s Law:** Governs yoke muscles (e.g., Right Lateral Rectus and Left Medial Rectus). It explains secondary deviation. * **Sherrington’s Law:** Governs reciprocal innervation of antagonistic muscles in the *same* eye (e.g., when the Right Lateral Rectus contracts, the Right Medial Rectus relaxes). * **Diplopia:** Paralytic squints typically present with diplopia that worsens in the direction of the paralyzed muscle’s action. * **Head Tilt:** Patients often adopt a compensatory head posture to minimize diplopia and maintain binocular single vision.

Question 180: Which of the following is NOT an action of the superior oblique muscle?

A. Extorsion (Correct Answer)
B. Depression
C. Abduction
D. Intorsion

Explanation: To master extraocular muscle actions for NEET-PG, remember the primary, secondary, and tertiary functions. The **Superior Oblique (SO)** muscle originates from the apex of the orbit but acts via the trochlea, inserting onto the posterior-superior-lateral quadrant of the globe. ### Why "Extorsion" is the Correct Answer The Superior Oblique is an **intortor**. In ophthalmology, the mnemonic **"SIN"** (Superior muscles are Intortors) is high-yield. Both the Superior Oblique and Superior Rectus perform intorsion. Therefore, **extorsion** is the opposite of its physiological action and is primarily performed by the inferior muscles (Inferior Oblique and Inferior Rectus). ### Analysis of Incorrect Options * **Intorsion (Option D):** This is the **primary** action of the SO. * **Depression (Option B):** This is the **secondary** action. The SO is most effective as a depressor when the eye is in an **adducted** position (visual axis aligned with the muscle's pull). * **Abduction (Option C):** This is the **tertiary** action. Because the SO inserts posterior to the equator, its contraction pulls the back of the eye medially, causing the front of the eye (cornea) to move laterally (abduction). ### NEET-PG Clinical Pearls * **Mnemonic for Obliques:** "O's are Abductors" (Both Superior and Inferior Obliques perform abduction). * **Testing Position:** To isolate the SO's depressing action clinically, ask the patient to look **"Down and In."** * **SO Palsy (4th Nerve):** Presents with **hypertropia** and **excylotorsion**. Patients often adopt a compensatory head tilt to the opposite shoulder to minimize diplopia (Bielschowsky Head Tilt Test).

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

Want unlimited practice?

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

Start For Free