Pediatric Ophthalmology and Strabismus — MCQs

Pediatric Ophthalmology and Strabismus Indian Medical PG Practice Questions and MCQs

Question 241: In clinical aniridia, all of the following are true except:

A. Iris is completely absent (Correct Answer)
B. Usually a familial condition
C. May be associated with congenital glaucoma
D. Ciliary processes may be visible

Explanation: **Explanation:** **Aniridia** is a misnomer. Despite the name suggesting a complete absence of the iris, it is characterized by **variable degrees of iris hypoplasia**. Clinically, a rudimentary stump of iris tissue is always present, though it may only be visible via gonioscopy or high-resolution imaging. Therefore, **Option A is the correct answer** because the iris is never "completely" absent. **Analysis of other options:** * **Option B:** Most cases (approx. 2/3) are **familial**, following an **Autosomal Dominant** inheritance pattern due to mutations in the **PAX6 gene** on chromosome 11p13. Sporadic cases (1/3) are associated with WAGR syndrome. * **Option C:** Congenital or developmental **glaucoma** occurs in about 50–75% of cases, often due to the rudimentary iris stump pulling forward and obstructing the trabecular meshwork (angle closure). * **Option D:** Because the iris is hypoplastic, the **ciliary processes** and the suspensory ligaments (zonules) of the lens are often clearly visible during a slit-lamp examination. **High-Yield Clinical Pearls for NEET-PG:** * **WAGR Syndrome:** Sporadic aniridia must be screened for **W**ilms tumor, **A**niridia, **G**enitourinary anomalies, and mental **R**etardation (deletion of 11p13). * **Associated Ocular Findings:** Foveal hypoplasia (leading to nystagmus and poor vision), polar cataracts, and limbal stem cell deficiency (pannus). * **Management:** Regular abdominal ultrasounds are mandatory in sporadic cases to rule out Wilms tumor.

Question 242: For a neonate born at 28 weeks of gestation who is being treated in the NICU for sepsis, at what corrected age should ROP screening be performed?

A. 30 weeks postmenstrual age (Correct Answer)
B. 32 weeks postmenstrual age
C. 34 weeks postmenstrual age
D. 36 weeks postmenstrual age

Explanation: ### Explanation **Concept:** Retinopathy of Prematurity (ROP) screening timing is based on the **Postmenstrual Age (PMA)**—the sum of gestational age at birth and the chronological age. According to the revised screening guidelines (National Neonatology Forum and AIOS), screening should be performed at **4 weeks (30 days) of chronological age** or **31 weeks PMA**, whichever is earlier. However, for extremely premature infants (born <28 weeks), the onset of ROP correlates more closely with the development of the retinal vasculature, which typically begins to show pathology around 30–31 weeks PMA. In this specific case (28 weeks gestation), 4 weeks of chronological age equals **32 weeks PMA**. However, the earliest recommended window to catch aggressive posterior ROP (AP-ROP) in very low birth weight infants starts at **30 weeks PMA**. **Analysis of Options:** * **A (30 weeks PMA):** This is the correct choice as it represents the earliest window for screening in very high-risk infants (born $\leq$ 28 weeks) to ensure early detection of pre-threshold disease. * **B (32 weeks PMA):** While many 28-weekers are screened at 32 weeks (4 weeks chronological age), 30 weeks is the safer, earlier threshold for extremely premature neonates. * **C & D (34/36 weeks PMA):** These are too late. Delaying screening to these ages increases the risk of missing the window for laser photocoagulation or anti-VEGF treatment, potentially leading to retinal detachment. **High-Yield Clinical Pearls for NEET-PG:** * **Screening Criteria (India):** Birth weight **$\leq$ 1750g** or Gestational Age **$\leq$ 34 weeks**. * **"When" to screen:** 4 weeks after birth. If born **<28 weeks** or **<1200g**, screen earlier at **2–3 weeks** of age. * **Zone I:** Centered on the disc (twice the distance from disc to fovea). Most critical zone. * **Plus Disease:** Characterized by arterial tortuosity and venous dilation in at least 2 quadrants; it is a sign of active, severe ROP. * **Treatment of Choice:** Peripheral retinal laser photocoagulation (Gold Standard) or Intravitreal Anti-VEGF.

Question 243: What is the most common eye tumor?

A. Retinoblastoma (Correct Answer)
B. Sarcoma
C. Medulloblastoma
D. Malignant melanoma

Explanation: **Explanation:** **Retinoblastoma (Option A)** is the correct answer because it is the most common primary intraocular malignancy of childhood. It arises from the neurosensory retina due to a mutation in the **RB1 gene** located on chromosome **13q14**. While it is the most common eye tumor in children, it is important to note that in adults, the most common primary intraocular tumor is Malignant Melanoma, and the most common intraocular tumor overall is Metastatic Carcinoma. However, in the context of standard medical examinations like NEET-PG, when "most common eye tumor" is asked without age qualification, Retinoblastoma is the prioritized answer. **Analysis of Incorrect Options:** * **Sarcoma (Option B):** These are mesenchymal tumors. While Rhabdomyosarcoma is the most common primary orbital malignancy in children, it is not an intraocular "eye tumor." * **Medulloblastoma (Option C):** This is a highly malignant primary brain tumor (primitive neuroectodermal tumor) originating in the cerebellum, not the eye. * **Malignant Melanoma (Option D):** This is the most common primary intraocular tumor in **adults**. It arises from uveal melanocytes (most commonly in the choroid). **High-Yield Clinical Pearls for NEET-PG:** * **Most common presenting sign:** Leukocoria (White pupillary reflex); second most common is Strabismus. * **Pathognomonic Histology:** Flexner-Wintersteiner rosettes (specific) and Homer-Wright rosettes (non-specific). * **Calcification:** Dystrophic calcification is a hallmark feature seen on B-scan USG or CT scan (Helpful for differential diagnosis from Coats' disease). * **Inheritance:** 40% are heritable (often bilateral/multifocal), 60% are non-heritable (usually unilateral).

Question 244: In infants, what is the cause of blindness arising out of oxygen toxicity?

A. Degeneration of the crystalline lens
B. Growth of blood vessels into the vitreous followed by fibrosis (Correct Answer)
C. Damage to the cornea
D. Enzymic defect in the lens

Explanation: ### Explanation The condition described is **Retinopathy of Prematurity (ROP)**, a vasoproliferative disorder affecting premature infants exposed to high concentrations of supplemental oxygen. **Why Option B is Correct:** The pathogenesis of ROP occurs in two phases. Initially, hyperoxia causes **vasoconstriction** and irreversible closure of immature retinal capillaries (vaso-obliteration). As the infant matures or is moved to room air, the non-perfused peripheral retina becomes ischemic and releases **Vascular Endothelial Growth Factor (VEGF)**. This triggers **neovascularization** (abnormal growth of blood vessels) from the retina into the vitreous. These fragile vessels leak and eventually undergo **fibrosis** and contraction, leading to tractional retinal detachment, which is the primary cause of blindness. **Why Other Options are Incorrect:** * **Option A & D:** Oxygen toxicity in neonates does not cause lens degeneration or enzymatic defects. While cataracts (lens opacity) can cause blindness, they are typically associated with metabolic disorders (e.g., Galactosemia) or congenital infections (e.g., Rubella), not oxygen-induced vaso-proliferation. * **Option C:** The cornea is not the target tissue for oxygen toxicity in infants. Corneal damage leading to blindness in children is more commonly associated with Vitamin A deficiency (Keratomalacia) or trauma. **Clinical Pearls for NEET-PG:** * **Screening Criteria:** In India, infants with birth weight **<1750g** or gestational age **<34 weeks** (or those with a stormy neonatal course) must be screened. * **Timing:** The first screening should be done at **4 weeks** of postnatal age or **31 weeks** of post-conceptional age (whichever is later). * **Plus Disease:** Characterized by dilatation and tortuosity of posterior pole retinal vessels; it indicates active, severe ROP. * **Treatment:** Peripheral retinal photo-coagulation (Laser) or Anti-VEGF injections (e.g., Ranibizumab).

Question 245: In a 2-year-old child, which medication is used for refractive error testing?

A. 1% atropine ointment (Correct Answer)
B. 1% atropine eye drop
C. Tropicamide 0.5%
D. Eucatropine 5%

Explanation: **Explanation:** In pediatric ophthalmology, the goal of refraction is to uncover the full hyperopic error by completely paralyzing the strong ciliary muscle (cycloplegia). **1. Why 1% Atropine Ointment is correct:** Atropine is the most potent cycloplegic available. In children under 5 years (especially those with accommodative esotropia), the ciliary muscle is very active, necessitating the strongest agent. **Ointment** is preferred over drops in toddlers because: * **Safety:** It minimizes systemic absorption through the nasolacrimal duct, reducing the risk of atropine toxicity (flushing, fever, tachycardia). * **Reliability:** It is easier to apply in a struggling child and is not washed away by tears. The standard regimen is twice daily for three days prior to the examination. **2. Why other options are incorrect:** * **1% Atropine eye drop:** While pharmacologically similar, drops carry a higher risk of systemic toxicity in small children due to rapid drainage into the nose and absorption through the mucosa. * **Tropicamide 0.5%:** This is a short-acting mydriatic with weak cycloplegic action. It is insufficient to overcome the accommodation of a 2-year-old and is typically used for adult fundus examinations. * **Eucatropine 5%:** This is a weak mydriatic rarely used in modern clinical practice and lacks the cycloplegic potency required for pediatric refraction. **Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC) by Age:** * < 5 years: Atropine (Ointment > Drops). * 5–15 years: Homatropine or Cyclopentolate. * > 15 years: Tropicamide or Phenylephrine. * **Atropine Toxicity Antidote:** Physostigmine. * **Contraindication:** Atropine should be avoided in children with Down syndrome as it may cause an exaggerated pupillary response and tachycardia.

Question 246: Diplopia is a characteristic feature of which of the following?

A. Concomitant squint
B. Non-paralytic squint
C. Paralytic squint (Correct Answer)
D. Latent squint

Explanation: **Explanation:** **1. Why Paralytic Squint is Correct:** Diplopia (double vision) occurs when the visual axes are misaligned, causing the image of an object to fall on the fovea of the fixing eye and on a non-foveal (extra-foveal) retinal point of the deviated eye. In **Paralytic Squint**, there is a sudden loss of motor coordination due to nerve or muscle palsy. Because the onset is typically acquired and the brain has already developed binocular single vision, it cannot immediately "ignore" the second image. This results in true binocular diplopia, which is most marked in the direction of the paralyzed muscle's action. **2. Why the Other Options are Incorrect:** * **Concomitant (Non-paralytic) Squint:** Usually occurs in early childhood. The developing brain utilizes compensatory mechanisms like **suppression** (ignoring the image from the deviated eye) or **amblyopia** to avoid diplopia. Therefore, diplopia is characteristically absent. * **Latent Squint (Heterophoria):** This is a condition where the deviation is kept latent by the power of sensory fusion. Diplopia only occurs if the phoria "breaks down" into a tropia due to fatigue or illness; otherwise, the eyes remain aligned under normal conditions. **3. Clinical Pearls for NEET-PG:** * **Primary vs. Secondary Deviation:** In paralytic squint, the **secondary deviation** (deviation of the sound eye when the paralyzed eye fixes) is always **greater** than the primary deviation (due to Hering’s Law of equal innervation). * **False Orientation (Past-pointing):** A hallmark of paralytic squint where the patient projects the image further than the object's actual position. * **Compensatory Head Posture:** Patients often tilt or turn their heads toward the direction of the paralyzed muscle to minimize diplopia.

Question 247: Visual acuity in infants is typically assessed using which of the following methods?

A. Landolt's rings (Correct Answer)
B. '4' dot test
C. Perimeter
D. Slit lamp

Explanation: **Explanation:** The assessment of visual acuity in infants and pre-verbal children requires specialized methods because they cannot read standard Snellen charts. **Why Landolt’s Rings is the correct answer:** Landolt’s rings (or the "Broken Ring" test) consist of a series of circles with gaps at different orientations (top, bottom, left, right). While traditionally used for adults, modified versions or **Preferential Looking (PL)** techniques using similar optotypes are employed for infants. In pediatric practice, visual acuity is assessed using the principle of **Resolution Acuity**. Methods include: * **Preferential Looking Tests:** (e.g., Teller Acuity Cards, Cardiff Acuity Cards) based on the fact that infants prefer looking at patterned stimuli over plain ones. * **Optokinetic Nystagmus (OKN):** Using a rotating drum. * **Visual Evoked Potential (VEP):** An objective electrophysiological measure. **Why other options are incorrect:** * **B. '4' dot test (Worth’s Four Dot Test):** This is used to assess **binocular single vision**, sensory fusion, and to detect suppression or anomalous retinal correspondence, not visual acuity. * **C. Perimeter:** This instrument is used to map the **visual field** (e.g., detecting glaucoma or neurological defects), which requires significant patient cooperation and fixation. * **D. Slit lamp:** This is a biomicroscope used for the **structural examination** of the anterior segment (cornea, iris, lens) and posterior segment of the eye, not for measuring functional visual acuity. **High-Yield Clinical Pearls for NEET-PG:** * **Fix and Follow:** The simplest clinical method to assess vision in an infant (usually present by 3–6 weeks of age). * **Catford Drum:** Used to estimate visual acuity by varying the size of an oscillating target. * **Visual Development:** At birth, visual acuity is approximately 6/600; it reaches adult levels (6/6) by age 3–5 years. * **Sheridan Gardiner Test:** The most reliable subjective test for children aged 3–5 years who know their letters but cannot read a chart.

Question 248: What is the instrument of choice for diagnosing pediatric retinal disorders?

A. Optical Coherence Tomography (OCT)
B. Fluorescein angiography
C. Slit lamp examination
D. Retcam (Correct Answer)

Explanation: **Explanation:** The **Retcam (Retinal Camera)** is the gold standard for diagnosing and documenting pediatric retinal disorders, most notably **Retinopathy of Prematurity (ROP)**. It is a wide-field digital imaging system specifically designed for infants. Unlike adult imaging tools, the Retcam uses a contact probe that fits easily between small palpebral fissures, providing a 130-degree view of the retina. This allows for objective documentation, remote screening (tele-ophthalmology), and monitoring of disease progression in neonates who cannot cooperate with traditional examinations. **Analysis of Incorrect Options:** * **Optical Coherence Tomography (OCT):** While excellent for macular pathology, standard tabletop OCT requires patient cooperation and a steady chin rest, making it impractical for infants. (Note: Handheld OCT exists but is not the primary screening tool). * **Fluorescein Angiography (FA):** This is an invasive procedure involving dye injection. While it can be performed using a Retcam (FA-mode), it is a specialized investigation rather than the primary diagnostic instrument of choice. * **Slit Lamp Examination:** This is used primarily for anterior segment evaluation. Even with a 90D lens, it is extremely difficult to perform on an uncooperative infant and provides a limited field of view compared to the Retcam. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard for ROP Screening:** Indirect Ophthalmoscopy (using a 28D lens) remains the clinical gold standard, but **Retcam** is the instrument of choice for digital documentation and objective diagnosis. * **Leukocoria:** Retcam is vital in the workup of a "white pupillary reflex" to differentiate between Retinoblastoma, Coats' disease, and ROP. * **Plus Disease in ROP:** Characterized by arterial tortuosity and venous dilation in at least 2 quadrants of the posterior pole; Retcam imaging is superior for tracking these vascular changes.

Question 249: A premature baby born at 29 weeks, examined at 42 weeks, shows stage 2 zone I ROP with plus disease in both eyes. How will you manage this patient?

A. Examination of the patient after 1 week
B. Laser photocoagulation of both eyes (Correct Answer)
C. Laser photocoagulation of the worse eye, follow-up of the other eye
D. Vitreoretinal surgery

Explanation: ### Explanation The management of Retinopathy of Prematurity (ROP) is guided by the **ETROP (Early Treatment for ROP) Study** criteria, which defines "Type 1 ROP" as requiring urgent treatment. **Why Option B is correct:** The patient has **Stage 2, Zone I with Plus disease**. According to ETROP criteria, **Type 1 ROP** includes: * Zone I, any stage with Plus disease (This patient's case) * Zone I, Stage 3 without Plus disease * Zone II, Stage 2 or 3 with Plus disease Type 1 ROP carries a high risk of progression to retinal detachment; therefore, **peripheral retinal ablation** (usually via Laser Photocoagulation) must be performed within **48–72 hours**. Since ROP is typically a bilateral symmetrical disease, both eyes require treatment. **Why other options are incorrect:** * **Option A:** Waiting one week is dangerous. Type 1 ROP is an ocular emergency; delay can lead to Stage 4 or 5 ROP (detachment). * **Option C:** ROP is a systemic vascular response affecting both eyes. If one eye meets treatment criteria, the other eye almost always requires simultaneous treatment or extremely close monitoring, but standard protocol for bilateral Type 1 is bilateral laser. * **Option D:** Surgery (Vitrectomy/Scleral buckling) is reserved for **Stage 4 or 5** (partial or total retinal detachment). **High-Yield Clinical Pearls for NEET-PG:** * **Screening Rule:** All babies born **<32 weeks** or **<1500g** (or 1500–2000g with unstable course) must be screened. * **First Screening:** Should be done at **4 weeks** post-natal age or **31 weeks** post-menstrual age (whichever is later). * **Plus Disease:** Characterized by dilation and tortuosity of posterior pole retinal vessels; it is the most important indicator of disease activity. * **Treatment Gold Standard:** Diode Laser Photocoagulation. Anti-VEGF (e.g., Ranibizumab) is an alternative, especially for Zone I disease.

Question 250: Refractive error most commonly concerned with divergent strabismus is:

A. Myopia (Correct Answer)
B. Astigmatism
C. Hypermetropia
D. Presbyopia

Explanation: ### Explanation **1. Why Myopia is Correct:** The association between refractive errors and strabismus is primarily driven by the **AC/A ratio (Accommodative Convergence to Accommodation ratio)**. In **Myopia** (nearsightedness), the patient has a clear near point and does not need to accommodate to see objects up close. Since accommodation and convergence are neurologically linked, a lack of accommodative effort leads to **decreased accommodative convergence**. This lack of inward pulling force allows the eyes to drift outward, resulting in **Divergent Strabismus (Exotropia)**. **2. Why Other Options are Incorrect:** * **Hypermetropia:** This is most commonly associated with **Convergent Strabismus (Esotropia)**. Hypermetropes must accommodate excessively to clear their vision; this over-accommodation triggers excessive accommodative convergence, pulling the eyes inward (Accommodative Esotropia). * **Astigmatism:** While uncorrected astigmatism can cause blurred vision and potentially lead to sensory strabismus, it does not have a specific, direct physiological link to divergence like myopia does. * **Presbyopia:** This is an age-related loss of accommodation in adults. While it affects the near point, it is not a primary cause of childhood strabismus. **3. High-Yield Clinical Pearls for NEET-PG:** * **Donders' Theory:** States that hypermetropia leads to esotropia and myopia leads to exotropia. * **Accommodative Esotropia:** Usually seen with hypermetropia of +2.00 to +7.00 D. * **Sensory Exotropia:** Occurs when one eye has poor vision (e.g., dense cataract or optic atrophy) in an adult or older child, leading to an outward drift. * **Management Tip:** The first step in treating accommodative strabismus is always the full correction of the refractive error with spectacles.

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