Pediatric Ophthalmology and Strabismus — MCQs

Pediatric Ophthalmology and Strabismus Indian Medical PG Practice Questions and MCQs

Question 231: What is the most common cause of bilateral proptosis in children?

A. Rhabdomyosarcoma
B. Primitive neuroectodermal tumor (PNET)
C. Retinoblastoma
D. Neuroblastoma (Correct Answer)

Explanation: **Explanation:** **Neuroblastoma** is the most common cause of **bilateral proptosis** in children. It is a malignant tumor arising from the sympathetic nervous system (most commonly the adrenal medulla). Proptosis occurs due to orbital metastasis, which typically involves the orbital bones. A classic clinical sign is "Panda eyes" or "Raccoon eyes" (periorbital ecchymosis), caused by the obstruction of palpebral vessels by the metastatic tumor. **Analysis of Incorrect Options:** * **Rhabdomyosarcoma (A):** This is the most common **primary** orbital malignancy in children. However, it typically presents as a **unilateral**, rapidly progressing proptosis rather than bilateral. * **Primitive Neuroectodermal Tumor (B):** While PNETs can involve the orbit, they are significantly rarer than neuroblastoma and do not typically present as the leading cause of bilateral proptosis. * **Retinoblastoma (C):** This is the most common primary intraocular tumor in children. While it can cause proptosis if there is extraocular extension, it is usually unilateral. Bilateral cases usually present with leukocoria (white pupillary reflex) rather than proptosis. **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 adults:** Thyroid Eye Disease (Graves' Ophthalmopathy). * **Neuroblastoma Association:** Look for increased urinary catecholamines (VMA/HVA) and an abdominal mass in the clinical vignette. * **Rhabdomyosarcoma:** Most common site is the **superonasal** quadrant of the orbit.

Question 232: In right lateral rectus palsy, all of the following are seen except?

A. Face turned to the right (Correct Answer)
B. Medial convergent squint
C. Inability to abduct the right eye
D. Diplopia

Explanation: In **Right Lateral Rectus (LR) Palsy** (6th Cranial Nerve Palsy), the primary deficit is the inability of the right eye to move outward (abduction). ### Why "Face turned to the right" is the correct answer: The question asks for the "except" option. In paralytic squint, the patient adopts a **compensatory head posture** to maintain binocular single vision and minimize diplopia. The rule is: **The face is turned in the direction of the action of the paralyzed muscle.** * The Right LR abducts the eye (moves it right). * Therefore, the patient turns their **face to the right** to bring the object of interest into the field of vision where the eyes are straightest. * *Note: There appears to be a clerical error in the provided key; "Face turned to the right" is actually a **feature** of Right LR palsy. If the question asks for "except," the incorrect statement would be "Face turned to the left." However, based on standard clinical presentation, all options A, B, C, and D are features of Right LR palsy.* ### Explanation of other options: * **Medial convergent squint (Option B):** Due to the unopposed action of the ipsilateral Medial Rectus, the affected eye deviates inward (Esotropia). * **Inability to abduct the right eye (Option C):** This is the hallmark sign, as the Lateral Rectus is the sole abductor of the eye. * **Diplopia (Option D):** Patients experience **horizontal, uncrossed (homonymous) diplopia**, which worsens on attempted abduction towards the paralyzed side. ### NEET-PG High-Yield Pearls: 1. **6th Nerve Palsy:** Most common isolated cranial nerve palsy. 2. **False Localizing Sign:** Increased intracranial pressure can cause 6th nerve palsy due to its long intracranial course over the petrous temporal bone. 3. **Diplopia Type:** LR palsy causes **uncrossed** diplopia (the image of the right eye is seen to the right). 4. **Bielschowsky Head Tilt Test:** Used for 4th nerve (Superior Oblique) palsy, not 6th nerve.

Question 233: What are the clinical features of sixth nerve palsy?

A. Convergent squint (Correct Answer)
B. Divergent squint
C. Limitation in upward movement
D. Limitation in downward movement

Explanation: **Explanation:** The **sixth cranial nerve (Abducens nerve)** innervates the **Lateral Rectus (LR)** muscle, which is responsible for the abduction (outward movement) of the eye. 1. **Why Option A is Correct:** In sixth nerve palsy, the Lateral Rectus is paralyzed. The **Medial Rectus (MR)**, which is its antagonist, remains unopposed. This results in the eye being pulled medially toward the nose, leading to an inward deviation known as **Convergent Squint (Esotropia)**. Patients typically present with horizontal diplopia (double vision) that worsens on attempting to look toward the side of the affected muscle. 2. **Why Other Options are Incorrect:** * **Option B (Divergent Squint):** This occurs in **Third Nerve Palsy** because the Lateral Rectus (CN VI) and Superior Oblique (CN IV) remain functional, pulling the eye "down and out." * **Options C & D (Limitation in vertical movement):** Vertical eye movements are controlled by the Third Nerve (Superior/Inferior Rectus and Inferior Oblique) and the Fourth Nerve (Superior Oblique). Sixth nerve palsy strictly affects horizontal abduction. **High-Yield Clinical Pearls for NEET-PG:** * **Longest Intracranial Course:** The Abducens nerve has the longest intracranial course, making it highly susceptible to damage from increased intracranial pressure (**False Localizing Sign**). * **Compensatory Head Posture:** Patients often turn their face **towards the side of the palsy** to minimize diplopia. * **Mnemonic:** **LR6SO4** (Lateral Rectus-6, Superior Oblique-4, all others-3). * **Common Causes:** Microvascular (Diabetes/Hypertension) in adults; trauma or tumors (like pontine glioma) in children.

Question 234: Leukokoria is seen in all of the following conditions except?

A. Congenital cataract
B. Persistent hyperplastic primary vitreous
C. Retinopathy of prematurity
D. Congenital glaucoma (Correct Answer)

Explanation: **Explanation:** **Leukokoria**, or a "white pupillary reflex," occurs when an intraocular pathology reflects light back through the pupil instead of the normal red reflex. **Why Congenital Glaucoma is the correct answer:** In **Congenital Glaucoma (Buphthalmos)**, the primary clinical presentation is a **cloudy or hazy cornea** due to corneal edema (secondary to high intraocular pressure) and an enlarged eyeball. It does not typically cause a white reflex from behind the pupil. Therefore, it is a cause of a "cloudy eye" but not true leukokoria. **Analysis of Incorrect Options:** * **Congenital Cataract:** This is the **most common cause** of leukokoria. Opacification of the lens prevents light from reaching the retina and reflects it back as a white reflex. * **Persistent Hyperplastic Primary Vitreous (PHPV):** Now often called Persistent Fetal Vasculature (PFV), this involves a failure of the embryological hyaloid vascular system to regress, creating a retrolental fibrovascular membrane that presents as leukokoria. * **Retinopathy of Prematurity (ROP):** In advanced stages (Stage 4 and 5), cicatricial changes and retinal detachment create a white mass behind the lens, leading to leukokoria. **NEET-PG High-Yield Pearls:** 1. **Retinoblastoma** is the most common **intraocular malignancy** presenting as leukokoria and must be ruled out first in any child with this sign. 2. **Differential Diagnosis of Leukokoria (The "White Pupil"):** Remember the mnemonic **"CHORP"** — **C**ataract, **H**eamangioma/PHPV, **O**cular Toxocariasis, **R**etinoblastoma/ROP, **P**ersistent Hyperplastic Primary Vitreous. 3. **Coats' Disease:** An idiopathic exudative retinopathy that is another classic cause of unilateral leukokoria in young males.

Question 235: Which of the following is the most common cause of vitreous hemorrhage in children?

A. Diabetic Retinopathy
B. Trauma (Correct Answer)
C. Eales disease
D. Coat's disease

Explanation: **Explanation:** **Vitreous hemorrhage (VH)** in the pediatric population is a significant clinical finding that often indicates severe underlying ocular pathology. **Why Trauma is the Correct Answer:** In children, **trauma** (both accidental and non-accidental) is the leading cause of vitreous hemorrhage, accounting for approximately **70% to 85%** of cases. This includes penetrating injuries, blunt trauma causing retinal tears, and Shaken Baby Syndrome (Non-accidental injury). In blunt trauma, the sudden anteroposterior compression and equatorial expansion of the globe lead to traction on the vitreous base or retinal vessels, resulting in hemorrhage. **Analysis of Incorrect Options:** * **Diabetic Retinopathy (A):** While this is the most common cause of VH in **adults**, it is extremely rare in children as proliferative changes typically take years to develop after the onset of Type 1 Diabetes. * **Eales Disease (B):** This is an idiopathic peripheral perivasculitis that primarily affects **young adult males** (20–40 years). It is a common cause of VH in the Indian subcontinent but is not the primary cause in the pediatric age group. * **Coats’ Disease (D):** This is a condition characterized by telangiectatic retinal vessels and exudation. While it can lead to retinal detachment, vitreous hemorrhage is a rare complication compared to trauma. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of VH in adults:** Proliferative Diabetic Retinopathy (PDR). * **Most common spontaneous (non-traumatic) cause of VH in children:** Pars Planitis or Persistent Fetal Vasculature (PFV). * **Terson Syndrome:** Vitreous hemorrhage associated with subarachnoid hemorrhage (due to a sudden rise in intracranial pressure). * **Management:** In children, early B-scan ultrasonography is mandatory to rule out retinal detachment, as visual deprivation can lead to permanent **amblyopia**.

Question 236: What is the most common cause of ophthalmia neonatorum?

A. Chlamydia (Correct Answer)
B. Gonorrhoea
C. Herpes Simplex Virus (HSV)
D. Staphylococcus aureus

Explanation: **Explanation:** **Ophthalmia Neonatorum** is defined as any conjunctivitis occurring within the first 30 days of life. **1. Why Chlamydia is Correct:** *Chlamydia trachomatis* (Serotypes D-K) is globally recognized as the **most common cause** of ophthalmia neonatorum. It typically presents 5 to 14 days after birth. The infection is acquired during passage through an infected birth canal. It is characterized by mucopurulent discharge and, if left untreated, can lead to conjunctival scarring and corneal pannus. Notably, it is also associated with systemic involvement, such as neonatal pneumonia. **2. Why the other options are incorrect:** * **B. Gonorrhoea:** *Neisseria gonorrhoeae* is the **most hyperacute and vision-threatening** cause, but it is less common than Chlamydia due to routine prenatal screening. It typically presents earlier (2–5 days) with profuse, thick purulent discharge and carries a high risk of corneal perforation. * **C. Herpes Simplex Virus (HSV):** HSV-2 is a viral cause presenting between 1–2 weeks. It is characterized by vesicular skin lesions and dendritic keratitis but is significantly rarer than bacterial causes. * **D. Staphylococcus aureus:** While a common cause of skin infections, it is a less frequent cause of neonatal conjunctivitis compared to the specialized pathogens acquired from the maternal genital tract. **High-Yield Clinical Pearls for NEET-PG:** * **Chemical Conjunctivitis:** Occurs within the first 24 hours (usually due to Silver Nitrate prophylaxis). * **Incubation Periods (High Yield):** * Chemical: <24 hours * Gonococcal: 2–5 days * Chlamydial: 5–14 days * **Treatment:** Systemic Erythromycin is the drug of choice for Chlamydial ophthalmia to prevent associated pneumonia. Topical treatment alone is insufficient. * **Prophylaxis:** Povidone-iodine (5%) or Erythromycin ointment is currently preferred over the historical Credé’s method (Silver Nitrate).

Question 237: What is the second most common malignancy in patients with retinoblastoma?

A. Osteosarcoma (Correct Answer)
B. Ewing's sarcoma
C. Medulloblastoma
D. Osteoblastoma

Explanation: **Explanation:** The correct answer is **Osteosarcoma**. Retinoblastoma is caused by a mutation in the **RB1 gene** (a tumor suppressor gene) located on chromosome **13q14**. In patients with the heritable (germline) form of the disease, every cell in the body carries one mutated allele. According to Knudson’s "Two-Hit Hypothesis," a second somatic mutation leads to tumor formation. Because the RB1 gene regulates the cell cycle globally, survivors of heritable retinoblastoma are at a significantly increased risk of developing **secondary non-ocular malignancies** later in life, especially if they received radiation therapy. * **Osteosarcoma** is the most common secondary malignancy, typically occurring in the femur or other long bones. * **Soft tissue sarcomas** (like fibrosarcoma) and **melanomas** are also frequently seen. **Why other options are incorrect:** * **Ewing’s sarcoma:** While a common pediatric bone tumor, it is associated with a chromosomal translocation t(11;22) and is not specifically linked to the RB1 mutation. * **Medulloblastoma:** Though it can occur in children, it is not the primary secondary malignancy associated with RB1. However, "Trilateral Retinoblastoma" refers to bilateral RB plus a pineoblastoma (not medulloblastoma). * **Osteoblastoma:** This is a benign bone-forming tumor and is not a common malignancy associated with genetic predisposition in RB survivors. **High-Yield Clinical Pearls for NEET-PG:** * **Trilateral Retinoblastoma:** Bilateral retinoblastoma associated with a midline intracranial tumor (usually **Pineoblastoma**). * **Most common site of metastasis:** Regional lymph nodes and bone marrow. * **Most common secondary malignancy:** Osteosarcoma. * **Flexner-Wintersteiner Rosettes:** Pathognomonic histological feature of retinoblastoma. * **Calcification:** Retinoblastoma is the most common cause of intraocular calcification in a child under 3 years.

Question 238: Which one of the following statements, concerning persistent hyperplastic primary vitreous (PHPV) is not true?

A. It is generally unilateral
B. Visual prognosis is usually good (Correct Answer)
C. It may calcify
D. It is most easily differentiated from retinoblastoma by the presence of exophthalmos or cataract

Explanation: **Explanation:** **Persistent Hyperplastic Primary Vitreous (PHPV)**, now more commonly termed **Persistent Fetal Vasculature (PFV)**, results from the failure of the primary vitreous and hyaloid vascular system to regress during fetal development. **Why Option B is the Correct Answer (The False Statement):** The visual prognosis in PHPV is generally **poor**. This is due to several factors: the presence of a dense retrolental membrane, associated foveal hypoplasia, tractional retinal detachment, and severe secondary amblyopia. Even with early surgical intervention (lensectomy and vitrectomy), achieving functional vision remains a significant clinical challenge. **Analysis of Other Options:** * **Option A (Unilateral):** PHPV is characteristically **unilateral** (90% of cases). This is a key clinical differentiator from other causes of leukocoria like Retinopathy of Prematurity (ROP), which is typically bilateral. * **Option C (Calcification):** While calcification is the hallmark of Retinoblastoma, PHPV can occasionally show dystrophic calcification in advanced stages, particularly if there is chronic intraocular hemorrhage or phthisis bulbi. * **Option D (Differentiation):** PHPV is a major differential for **Leukocoria** (white pupillary reflex). It is distinguished from Retinoblastoma by the presence of a **congenital cataract** or a microphthalmic eye. Retinoblastoma typically presents in a normal-sized eye without a primary cataract. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Presentation:** Unilateral leukocoria in a **microphthalmic eye** with elongated ciliary processes. * **Mittendorf Dot:** A remnant of the hyaloid artery on the posterior lens capsule (minor form of PFV). * **Bergmeister’s Papilla:** A remnant of the hyaloid artery on the optic disc. * **Imaging:** Ultrasound or CT shows a persistent hyaloid stalk (Cloquet’s canal) and absence of large calcified masses (unlike Retinoblastoma).

Question 239: Most bilateral multifocal retinoblastoma require which of the following?

A. Chemotherapy
B. Radiotherapy
C. Enucleation
D. Multimodality therapy (Correct Answer)

Explanation: **Explanation:** **Retinoblastoma (RB)** is the most common primary intraocular malignancy in children. The management of RB has evolved from life-saving to eye-saving and vision-preserving. **Why Multimodality Therapy is Correct:** Bilateral and multifocal cases are almost always **germline mutations** (hereditary). Because these patients have multiple tumors in both eyes, a single modality is rarely sufficient. **Multimodality therapy** is the standard of care to achieve "chemoreduction" followed by "consolidation." 1. **Systemic Chemotherapy (VEC protocol: Vincristine, Etoposide, Carboplatin):** Used to shrink the tumor volume. 2. **Local Therapy (Focal Consolidation):** Once shrunk, residual tumors are treated with Cryotherapy, Transpupillary Thermotherapy (TTT), or Brachytherapy. 3. **Intravitreal/Intra-arterial Chemotherapy:** Used for vitreous seeds or resistant tumors. **Why Other Options are Incorrect:** * **Chemotherapy (A):** While essential, it is rarely used alone as it carries a high risk of tumor recurrence without focal consolidation. * **Radiotherapy (B):** External Beam Radiation Therapy (EBRT) is now a **last resort** due to the high risk of secondary malignancies (like osteosarcoma) in children with germline mutations. * **Enucleation (C):** This is the treatment of choice for **Group E (advanced)** unilateral cases. In bilateral cases, the goal is to save at least one (if not both) eyes; enucleation is reserved only for the more severely affected eye if it has no visual potential. **High-Yield Clinical Pearls for NEET-PG:** * **Most common presenting sign:** Leukocoria (60%), followed by Strabismus. * **Pathognomonic Histology:** Flexner-Wintersteiner rosettes. * **Calcification:** A hallmark feature on CT scan (helps differentiate from Coats' disease). * **Classification:** The International Classification of Retinoblastoma (ICRB) groups tumors from A to E based on prognosis for eye salvage.

Question 240: A patient is diagnosed with retinoblastoma, presenting with a single tumor in one eye. The patient is concerned about the risk of their children developing the same condition. What test can be used to determine if the tumor is heritable or sporadic?

A. DNA footprinting
B. Fluorescence-activated cell sorting (FACS)
C. Northern blotting
D. Polymerase Chain Reaction (PCR) (Correct Answer)

Explanation: **Explanation:** The clinical scenario describes a patient with **unilateral retinoblastoma**. While 60% of retinoblastoma cases are sporadic and non-heritable, approximately 15% of unilateral cases are actually germline mutations (heritable). To determine the risk for future offspring, genetic analysis of the **RB1 gene** (located on chromosome 13q14) is essential. **Why PCR is the correct answer:** **Polymerase Chain Reaction (PCR)** is the gold standard technique for amplifying specific DNA sequences. In retinoblastoma, PCR is used to amplify the exons of the RB1 gene from the patient's peripheral blood lymphocytes. Once amplified, techniques like **Direct DNA Sequencing** or **Multiplex Ligation-dependent Probe Amplification (MLPA)** are used to identify point mutations, deletions, or insertions. If a mutation is found in the blood (germline), the condition is heritable; if it is only found in the tumor tissue, it is sporadic. **Why the other options are incorrect:** * **DNA Footprinting:** Used to identify the specific site where a protein (like a transcription factor) binds to a DNA sequence. It is a research tool, not a clinical diagnostic test for mutations. * **FACS:** A flow cytometry technique used to sort cells based on size and surface markers (e.g., CD4 counts in HIV). It does not analyze genetic mutations. * **Northern Blotting:** Used to detect and quantify **RNA** levels to study gene expression. It is not used for detecting primary DNA mutations in the RB1 gene. **High-Yield Clinical Pearls for NEET-PG:** * **Knudson’s Two-Hit Hypothesis:** Heritable cases have the "first hit" in the germline; sporadic cases require two "hits" in the same somatic cell. * **Most common intraocular malignancy** in children. * **Most common presenting sign:** Leukocoria (White pupillary reflex). * **Pathology:** Flexner-Wintersteiner rosettes are pathognomonic. * **Associated Risk:** Patients with germline RB1 mutations have a high risk of secondary malignancies, most commonly **Osteosarcoma**.

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