Pediatric Ophthalmology and Strabismus Practice Questions

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

Leukemia. **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.

Q: All of the following are true for retinoblastoma except?

Always unilateral. **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.

Q: True about paralytic squint is:

Binocular diplopia. **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.

Q: Regarding amblyopia, which of the following is true?

All of the above.. **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.

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

Retinoblastoma. **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.

Q: What is the treatment for a small retinoblastoma tumor?

Brachytherapy. **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.

Q: Secondary deviation is more than primary deviation is a feature of?

Paralytic squint. ### 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.

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

Extorsion. 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).

Question 1

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

Accepted Answer

Leukemia

Answer

Neurofibromatosis

Answer

Cavernous hemangioma

Answer

Malignant fibrous histiocytoma

Question 2

All of the following are true for retinoblastoma except?

Accepted Answer

Always unilateral

Answer

Leucocoria is the most common presentation

Answer

May have family history

Answer

Most common age group affected is 1-2 years

Question 3

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

Accepted Answer

Mantoux test

Answer

Hemogram

Answer

X-ray of sacroiliac joint

Answer

HIV test

Question 4

True about paralytic squint is:

Accepted Answer

Binocular diplopia

Answer

Uniocular diplopia

Answer

The person cannot use the two eyes together

Answer

Diminished visual acuity

Question 5

Regarding amblyopia, which of the following is true?

Accepted Answer

All of the above.

Answer

It is a reversible loss of vision.

Answer

It is associated with squint.

Answer

It is a defect in refractive error.

Question 6

What is the typical pupil size of a newborn?

Accepted Answer

Constricted

Answer

Dilated

Answer

Mid-dilated

Answer

Normal

Question 7

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

Accepted Answer

Retinoblastoma

Answer

Squamous cell carcinoma

Answer

Neurofibroma

Answer

Keratoacanthoma

Question 8

What is the treatment for a small retinoblastoma tumor?

Accepted Answer

Brachytherapy

Answer

Enucleation

Answer

Eviceration

Answer

Chemotherapy

Question 9

Secondary deviation is more than primary deviation is a feature of?

Accepted Answer

Paralytic squint

Answer

Accommodative squint

Answer

Infantile esotropia

Answer

Alternate exotropia

Question 10

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

Accepted Answer

Extorsion

Answer

Depression

Answer

Abduction

Answer

Intorsion

Pediatric Ophthalmology and Strabismus — MCQs

Pediatric Ophthalmology and Strabismus — MCQs

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