Free ABO Pediatric Ophthalmology and Strabismus Questions and Answers — Questions and Answers
Question 1: A 9-month-old infant presents with a history of persistent tearing and mild mattering in the left eye since birth. The eye is not red, and the cornea is clear. The mother reports that symptoms are worse in the cold or wind. What is the most appropriate initial management for this patient?
- Immediate surgical probing of the nasolacrimal duct.
- Prescription of a topical antibiotic-steroid combination.
- Observation and instruction on digital lacrimal sac massage. (Correct answer)
- Referral for a dacryocystorhinostomy (DCR).
Correct answer: Observation and instruction on digital lacrimal sac massage.
This presentation is classic for congenital nasolacrimal duct obstruction (NLDO). The vast majority of cases (>90%) resolve spontaneously within the first year of life. Therefore, the most appropriate initial management is conservative, consisting of observation and teaching the parent how to perform Crigler (digital lacrimal sac) massage to increase hydrostatic pressure and open the membranous obstruction at the valve of Hasner. Surgical probing is typically deferred until after 12 months of age if the condition persists. Antibiotics are only for active infection (dacryocystitis), and steroids are not indicated. DCR is a much more invasive surgery reserved for complex cases or failures of less invasive procedures.
Question 2: A 3-year-old child presents with an intermittent inward turning of the right eye, first noticed six months ago. The deviation is more prominent when the child is looking at toys up close. Cycloplegic refraction reveals +5.00 D sphere in both eyes. What is the most appropriate initial treatment?
- Bilateral medial rectus muscle recession.
- Patching of the left eye for 6 hours per day.
- Prescription of the full cycloplegic hyperopic correction. (Correct answer)
- Botulinum toxin injection into the medial rectus muscles.
Correct answer: Prescription of the full cycloplegic hyperopic correction.
This is a classic presentation of refractive accommodative esotropia. The esotropia is caused by the excessive accommodative effort required to see clearly through the significant uncorrected hyperopia, which in turn drives excessive convergence. The cornerstone and initial treatment is to prescribe the full cycloplegic refractive error in spectacles. This relaxes accommodation, thereby reducing the convergence drive and straightening the eyes. Surgery is only considered if a significant esotropia persists even with full spectacle correction (partially accommodative esotropia). Patching is a treatment for amblyopia, not the strabismus itself, and botulinum toxin is not the primary therapy.
Question 3: A pediatrician performing a red reflex test on a 6-month-old infant notes a white pupillary reflex (leukocoria) in the right eye. While retinoblastoma is the most life-threatening cause, what is the most common overall cause of leukocoria in children?
- Retinoblastoma
- Coats' disease
- Persistent fetal vasculature (PFV)
- Congenital cataract (Correct answer)
Correct answer: Congenital cataract
While retinoblastoma is the most feared and life-threatening cause of leukocoria, congenital cataract is statistically the most common cause. It is critical to refer any child with leukocoria for an urgent, dilated ophthalmologic examination to differentiate the cause. Coats' disease, persistent fetal vasculature, and retinoblastoma are other important causes in the differential diagnosis but are less common than congenital cataracts.
Question 4: A 7-year-old child is examined for an abnormal head posture. On examination, there is a marked limitation of abduction in the left eye. When the child attempts to adduct the left eye (look to the right), you observe narrowing of the palpebral fissure and globe retraction. What is the most likely diagnosis?
- Sixth (abducens) nerve palsy
- Brown syndrome
- Duane retraction syndrome (Correct answer)
- Möbius syndrome
Correct answer: Duane retraction syndrome
The combination of limited abduction with globe retraction and palpebral fissure narrowing on adduction is the pathognomonic triad for Duane retraction syndrome. This condition is a congenital cranial dysinnervation disorder, where the lateral rectus muscle is aberrantly innervated by a branch of the oculomotor (third) nerve. An isolated sixth nerve palsy causes an abduction deficit but not retraction on adduction. Brown syndrome restricts elevation in adduction. Möbius syndrome involves bilateral sixth and seventh nerve palsies.
Question 5: A 5-year-old is diagnosed with intermittent exotropia. The parents report the child's left eye drifts outward primarily when tired or looking in the distance. Which of the following findings is a primary indication for considering surgical intervention?
- The deviation measures 15 prism diopters at distance.
- The child frequently closes one eye in bright sunlight.
- The deviation is manifest for more than 50% of waking hours. (Correct answer)
- The near stereoacuity is 200 seconds of arc.
Correct answer: The deviation is manifest for more than 50% of waking hours.
The decision to operate on intermittent exotropia is multifactorial, but a primary indication is deteriorating fusional control. A deviation that is manifest (tropic) for more than 50% of waking hours is a widely accepted guideline indicating poor control and is a strong indication for surgery to preserve or restore binocular function. Closing one eye in the sun is a common symptom but not a sole indication for surgery. The size of the deviation and stereoacuity are important factors, but the frequency of the manifest deviation is a more direct measure of control.
Question 6: According to the Pediatric Eye Disease Investigator Group (PEDIG) Amblyopia Treatment Studies, which of the following is true regarding the treatment of moderate amblyopia (20/40 to 20/80) in children aged 3 to <7 years?
- Patching for 6 hours daily is significantly more effective than patching for 2 hours daily.
- Daily atropine 1% was found to be superior to patching.
- Patching for 2 hours daily was found to be as effective as patching for 6 hours daily. (Correct answer)
- Optical correction alone is ineffective and patching must be started immediately.
Correct answer: Patching for 2 hours daily was found to be as effective as patching for 6 hours daily.
A landmark PEDIG study (ATS1) demonstrated that for children aged 3 to <7 years with moderate amblyopia (visual acuity 20/40 to 20/80), patching the sound eye for 2 hours per day was as effective as patching for 6 hours per day. This finding changed clinical practice, allowing for reduced treatment burden with similar efficacy. Subsequent studies showed atropine to be a comparable alternative to patching, not superior. Other studies have also shown that a significant number of children improve with optical correction alone, which should be tried first.
Free ABO Pediatric Ophthalmology and Strabismus Questions and Answers
A 9-month-old infant presents with a history of persistent tearing and mild mattering in the left eye since birth.
The eye is not red, and the cornea is clear.
The mother reports that symptoms are worse in the cold or wind.
What is the most appropriate initial management for this patient?