Pediatric Ophthalmology and Strabismus Practice Questions

Q: Which of the following ophthalmological anomalies is seen in WAGR syndrome?

Aniridia. **Explanation:** **WAGR Syndrome** is a rare genetic contiguous gene deletion syndrome caused by the microdeletion of chromosome **11p13**. The acronym stands for **W**ilms tumor, **A**niridia, **G**enitourinary anomalies, and mental **R**etardation. **Why Aniridia is the correct answer:** The deletion involves the **PAX6 gene**, which is the "master control gene" for eye development. A mutation or deletion of PAX6 leads to **Aniridia** (partial or complete absence of the iris). In WAGR syndrome, aniridia is often the first clinical sign noted at birth and serves as a critical marker for the potential development of Wilms tumor (nephroblastoma). **Analysis of Incorrect Options:** * **Lens coloboma:** While colobomas are congenital anomalies, they are typically associated with the *CHARGE* syndrome or isolated genetic defects, not specifically the 11p13 deletion. * **Retinitis pigmentosa:** This is a hereditary retinal dystrophy involving photoreceptors. It is not a component of the WAGR complex. * **Trabeculodysgenesis:** This is the underlying structural defect in *Primary Congenital Glaucoma*. While patients with aniridia can develop secondary glaucoma (due to synechial closure of the angle), trabeculodysgenesis is not the defining feature of WAGR. **High-Yield Clinical Pearls for NEET-PG:** * **Genetics:** Microdeletion of **11p13** affecting **WT1** (Wilms tumor) and **PAX6** (Aniridia) genes. * **Monitoring:** Children with isolated aniridia must be screened with serial abdominal ultrasounds every 3 months until age 7 to detect Wilms tumor early. * **Ocular Complications of Aniridia:** Glaucoma (most common), foveal hypoplasia (leading to nystagmus and poor vision), and limbal stem cell deficiency. * **Gillespie Syndrome:** A variant featuring aniridia, cerebellar ataxia, and mental retardation (distinct from WAGR).

Q: All of the following may be present in Duane's retraction syndrome except?

Narrowing of palpebral fissure in abduction. **Explanation:** Duane’s Retraction Syndrome (DRS) is a congenital cranial dysinnervation disorder caused by the absence or hypoplasia of the **abducens (VI) nerve** nucleus, with paradoxical innervation of the lateral rectus by the **oculomotor (III) nerve**. **Why Option C is the correct answer:** In DRS, the hallmark feature is the **narrowing of the palpebral fissure on adduction**, not abduction. This occurs because, during adduction, both the medial and lateral recti receive nerve impulses simultaneously (co-contraction). This "tug-of-war" effect pulls the globe into the orbit (enophthalmos), causing the eyelids to close slightly. Conversely, on abduction, the palpebral fissure typically widens. **Analysis of Incorrect Options:** * **Option A (Suppression):** Since DRS is usually congenital and unilateral, children develop suppression of the affected eye to avoid diplopia. Amblyopia may also occur. * **Option B (Head turn):** Patients often adopt a compensatory face turn toward the side of the affected eye to maintain binocular single vision and minimize the deviation. * **Option D (Limitation of abduction):** This is a primary feature of DRS (especially Type 1, the most common type), resulting from the lack of innervation by the VI nerve to the lateral rectus. **High-Yield Clinical Pearls for NEET-PG:** * **Huber’s Classification:** * **Type 1:** Limited Abduction (Most common). * **Type 2:** Limited Adduction. * **Type 3:** Limited both Abduction and Adduction. * **Associated Findings:** "Upshoot" or "downshoot" of the eye during adduction. * **Epidemiology:** More common in females and usually affects the **left eye**. * **Systemic Association:** Often associated with **Goldenhar Syndrome**.

Q: What is the most common cause of leukocoria in a newborn?

Congenital cataract. **Explanation:** **Leukocoria**, or a "white pupillary reflex," is a critical clinical sign in pediatric ophthalmology. While several conditions can cause this, **Congenital Cataract** is statistically the **most common cause** of leukocoria in newborns. It involves an opacification of the crystalline lens present at birth, which obstructs the normal red reflex. Early diagnosis is vital to prevent irreversible amblyopia. **Analysis of Options:** * **A. Congenital Cataract (Correct):** It is the leading cause of preventable blindness in children and the most frequent cause of a white reflex in the neonatal period. * **B. Toxocara infection:** This typically presents in older children (preschool/school age) who have contact with puppies or soil. It causes a posterior pole granuloma but is rarely seen in newborns. * **C. Retinoblastoma:** This is the **most common primary intraocular malignancy** in children and the most common *life-threatening* cause of leukocoria. However, it usually presents between 12–18 months of age, not typically at birth. * **D. CMV infection:** While CMV is a common congenital infection, it typically manifests as chorioretinitis rather than a dense white pupillary reflex. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of leukocoria overall:** Congenital Cataract. * **Most common life-threatening cause of leukocoria:** Retinoblastoma. * **Differential Diagnosis (DDx) of Leukocoria:** Remember the mnemonic **"C-R-P"** (Cataract, Retinoblastoma, PHPV/PFV). * **Coats’ Disease:** A common cause of unilateral leukocoria in young males due to telangiectatic retinal vessels and exudation. * **Management:** Congenital cataracts that are visually significant (central, >3mm) should ideally be operated on within the first 4–6 weeks of life to ensure proper visual development.

Q: What is the primary treatment for metastatic disease in retinoblastoma?

Chemotherapy. **Explanation:** **Retinoblastoma** is the most common intraocular malignancy in children. When the disease remains intraocular, the goal is to save the eye and vision. However, once it becomes **metastatic** (spreading to the bone marrow, lymph nodes, or CNS), the condition is systemic and life-threatening. 1. **Why Chemotherapy is Correct:** Metastatic retinoblastoma requires a **systemic approach** to eliminate circulating malignant cells throughout the body. High-dose systemic chemotherapy (often followed by autologous stem cell rescue) is the mainstay of treatment. It is the only modality capable of addressing multi-organ involvement and crossing the blood-brain barrier (in specific protocols) to treat micrometastases. 2. **Why Other Options are Incorrect:** * **Enucleation:** This is a local surgical treatment. While it is the treatment of choice for advanced intraocular tumors (Group E) to prevent spread, it cannot treat disease that has already metastasized. * **Radiotherapy:** External Beam Radiotherapy (EBRT) is a local/regional treatment. While used for orbital recurrence or CNS involvement, it is not the primary treatment for generalized metastatic disease due to the risk of secondary malignancies (especially in patients with the *RB1* germline mutation). * **Cryotherapy:** This is a focal "cold" therapy used only for small, anteriorly located intraocular tumors (less than 3mm in diameter and 2mm in thickness). **High-Yield Clinical Pearls for NEET-PG:** * **Most common site of metastasis:** Direct extension via the **optic nerve** to the CNS. * **Most common distant metastasis:** Bone marrow and skeleton. * **Chemoreduction:** The use of chemotherapy (Vincristine, Etoposide, Carboplatin) to shrink an intraocular tumor to make it amenable to local therapies (like laser or cryo). * **Trilateral Retinoblastoma:** Bilateral retinoblastoma associated with a pineal gland tumor (pineoblastoma).

Q: Exotropia occurs due to which of the following?

Third nerve palsy. **Explanation:** **1. Why Third Nerve Palsy is Correct:** The Oculomotor (3rd) nerve innervates four of the six extraocular muscles: the Medial Rectus (MR), Superior Rectus, Inferior Rectus, and Inferior Oblique. The MR is the primary muscle responsible for **adduction** (turning the eye inward). In a 3rd nerve palsy, the MR is paralyzed, leaving the **Lateral Rectus** (innervated by the 6th nerve) unopposed. This results in the eye being pulled outward, leading to **Exotropia** (divergent squint). Clinically, this presents as a "down and out" eye position due to the unopposed action of the Lateral Rectus and Superior Oblique. **2. Why the Other Options are Incorrect:** * **Optic Neuritis:** This is an inflammatory condition of the optic nerve (CN II). It affects vision and pupillary light reflex (RAPD) but does not directly cause ocular deviation or squint. * **Abducens (6th) Nerve Palsy:** The 6th nerve innervates the Lateral Rectus. Paralysis of this muscle leads to unopposed action of the Medial Rectus, resulting in **Esotropia** (convergent squint), not exotropia. * **Papilloedema:** This refers to bilateral optic disc swelling due to increased intracranial pressure. While it may cause a secondary 6th nerve palsy (false localizing sign) leading to esotropia, it does not inherently cause exotropia. **NEET-PG High-Yield Pearls:** * **3rd Nerve Palsy Triad:** Ptosis, "Down and Out" eye, and Mydriasis (if parasympathetic fibers are involved). * **Rule of Pupil:** Pupil involvement suggests compressive lesions (e.g., PCom artery aneurysm); pupil sparing suggests ischemic causes (e.g., Diabetes). * **Primary Divergent Squint:** Most commonly seen as Intermittent Exotropia (X(T)) in children.

Q: According to WHO, which method is applied for prophylactic use in ophthalmia neonatorum?

Silver nitrate solution. **Explanation:** **Ophthalmia Neonatorum** is a form of conjunctivitis occurring within the first 30 days of life, typically contracted during passage through the birth canal. **1. Why Silver Nitrate is Correct:** The use of **1% Silver Nitrate solution** is known as **Credé’s Prophylaxis**. Historically, it was the first widely adopted method to prevent gonococcal ophthalmia neonatorum. While many developed countries have switched to antibiotic ointments due to the risk of chemical conjunctivitis, the **WHO** continues to recommend 1% Silver Nitrate (or 1% Tetracycline/0.5% Erythromycin) as a cost-effective and accessible prophylactic agent in many settings to prevent *Neisseria gonorrhoeae* infection, which can lead to corneal perforation and blindness. **2. Analysis of Incorrect Options:** * **B & C (Erythromycin/Tetracycline):** While these are the preferred prophylactic agents in the US (CDC guidelines) because they are less irritating than silver nitrate and provide some coverage against *Chlamydia*, the question specifically asks for the classic WHO-recommended prophylactic method often associated with Credé’s method in standard textbooks. * **D (Penicillin injection):** Systemic penicillin is used for the **treatment** of confirmed gonococcal conjunctivitis, not as a routine prophylactic topical measure. **3. High-Yield Clinical Pearls for NEET-PG:** * **Most Common Cause overall:** *Chlamydia trachomatis* (presents at 5–14 days). * **Most Dangerous Cause:** *Neisseria gonorrhoeae* (presents early, 2–5 days; can penetrate intact corneal epithelium). * **Chemical Conjunctivitis:** Occurs within the first 24 hours; typically caused by Silver Nitrate itself. * **Incubation Periods:** * Chemical: <24 hours * Gonococcal: 2–5 days * Chlamydial: 5–14 days * Herpes Simplex: 1–2 weeks

Q: The following light reflex is seen in a patient. How much is the deviation?

45 PD. ***45 PD*** - The image displays the **Hirschberg test** (corneal light reflex test), which estimates the angle of strabismus. The light reflex is displaced nasally in the left eye, indicating an outward deviation (**exotropia**). - A reflex located approximately midway between the pupil margin and the limbus corresponds to a deviation of about 22.5 degrees, which is equivalent to **45 prism diopters (PD)**. *30 PD* - A deviation of 30 PD corresponds to approximately 15 degrees, where the light reflex would be seen at the **pupillary margin**. - This represents a smaller deviation than what is depicted in the image. *90 PD* - This value corresponds to a large deviation of 45 degrees, where the light reflex would be located at the **limbus** (the junction of the cornea and sclera). - The light reflex in the image is positioned midway between the pupil and limbus, indicating a smaller deviation than what would be seen with a full 90 PD deviation. *90°* - This is an extremely large deviation and is also an incorrect unit of measurement for this test; **prism diopters (PD)** are the standard unit used to quantify strabismus. - One degree of deviation is roughly equal to two prism diopters, making a 90-degree deviation (180 PD) anatomically inconsistent with the image.

Question 1

Which of the following ophthalmological anomalies is seen in WAGR syndrome?

Accepted Answer

Aniridia

Answer

Lens coloboma

Answer

Retinitis pigmentosa

Answer

Trabeculodysgenesis

Question 2

All of the following may be present in Duane's retraction syndrome except?

Accepted Answer

Narrowing of palpebral fissure in abduction

Answer

Suppression

Answer

Head turn

Answer

Limitation of abduction

Question 3

What is the test used to assess visual acuity in an infant less than one year of age?

Accepted Answer

Electroretinography

Answer

Electrooculography

Answer

Snellen's chart

Answer

Optical Coherence Tomography

Question 4

What is the most common cause of leukocoria in a newborn?

Accepted Answer

Congenital cataract

Answer

Toxocara infection

Answer

Retinoblastoma

Answer

CMV infection

Question 5

What is the primary treatment for metastatic disease in retinoblastoma?

Accepted Answer

Chemotherapy

Answer

Enucleation

Answer

Radiotherapy

Answer

Cryotherapy

Question 6

Exotropia occurs due to which of the following?

Accepted Answer

Third nerve palsy

Answer

Optic neuritis

Answer

Abducens nerve palsy

Answer

Papilloedema

Question 7

According to WHO, which method is applied for prophylactic use in ophthalmia neonatorum?

Accepted Answer

Silver nitrate solution

Answer

Erythromycin ointment

Answer

Tetracycline ointment

Answer

Penicillin injection

Question 8

An 'A' pattern squint is typically associated with weakness or overaction of which extraocular muscle?

Accepted Answer

Superior oblique

Answer

Superior rectus

Answer

Inferior rectus

Answer

Inferior oblique

Question 9

Diplopia is not a presenting feature in which of the following conditions?

Accepted Answer

Latent squint

Answer

Manifest squint

Answer

Paralytic squint

Answer

Anisometropia

Question 10

The following light reflex is seen in a patient. How much is the deviation?

Accepted Answer

45 PD

Answer

90 PD

Answer

30 PD

Answer

90°

Pediatric Ophthalmology and Strabismus — MCQs

Pediatric Ophthalmology and Strabismus — MCQs

On this page

Practice by Chapter

Want unlimited practice?