NBEO - National Board of Examiners in Optometry Binocular Vision and Pediatrics Questions and Answers

Question 1

A 4-year-old boy presents with a constant, large-angle esotropia that his parents report has been present since he was 4 months old. He cross-fixates, and visual acuity is equal in both eyes. Cycloplegic refraction reveals +1.50 D sphere in both eyes. Which of the following is the MOST likely diagnosis?

Accepted Answer

Infantile esotropia

Answer

Infantile esotropia is characterized by a large-angle, constant esotropia with an onset before 6 months of age. Cross-fixation is a common feature, which often helps maintain equal visual acuity in both eyes. The refractive error is typically a low to moderate hyperopia, which is not the primary cause of the deviation, unlike accommodative esotropia. [4, 9, 11]

Question 2

A 9-year-old complains of headaches, intermittent blurred vision, and losing her place while reading. Clinical testing reveals a receded near point of convergence (NPC) to 15 cm break / 20 cm recovery, reduced positive fusional vergence (PFV) at near, and an exophoria of 10 prism diopters at near. What is the MOST appropriate initial management?

Accepted Answer

Office-based vision therapy

Answer

The patient's symptoms (asthenopia, blurred vision, difficulty with reading) and clinical signs (receded NPC, reduced PFV, near exophoria) are classic for convergence insufficiency (CI). [5, 6, 8, 10] Office-based vision therapy is the most effective and evidence-based treatment for improving convergence ability and alleviating symptoms in children with CI. [5, 8]

Question 3

According to the Amblyopia Treatment Studies (ATS), which of the following is an effective initial treatment for a 5-year-old child with moderate amblyopia (20/80) due to strabismus?

Accepted Answer

Daily patching of the sound eye for 2 hours

Answer

The Pediatric Eye Disease Investigator Group (PEDIG) Amblyopia Treatment Studies (ATS) demonstrated that for moderate amblyopia (20/40 to 20/100) in children aged 3 to <7 years, patching the sound eye for 2 hours daily is as effective as patching for 6 hours daily. [16, 17, 18] This minimal effective dose is often preferred to enhance compliance.

Question 4

A 6-year-old child with intermittent exotropia (X(T)) is asymptomatic, but the deviation is manifest more than 50% of the time. Which of the following is a common non-surgical management option used to improve control of the deviation and potentially delay surgery?

Accepted Answer

Over-minus lens therapy

Answer

Over-minus lens therapy (e.g., prescribing an additional -2.00 D to -3.00 D over the cycloplegic refraction) is a non-surgical option used in intermittent exotropia. The additional minus power stimulates accommodative convergence, which in turn helps to control the exodeviation. This is often used for younger children to improve fusion and delay the need for surgery. [2, 3, 21]

Question 5

A 4-year-old child is undergoing a binocular vision evaluation. Using the Randot Preschool Stereoacuity Test, what level of stereoacuity would be considered within the normal range for this age?

Accepted Answer

70 seconds of arc

Answer

Normative data for stereoacuity shows a developmental progression. For a 4-year-old child, the median stereoacuity on the Randot test is typically around 70 seconds of arc. Expecting adult-like levels (e.g., 20-40 seconds of arc) is not appropriate, while gross stereopsis like 400 seconds of arc would be expected in a younger child or could indicate a problem. [1, 15, 26]

NBEO - National Board of Examiners in Optometry Practice Test

NBEO - National Board of Examiners in Optometry Practice Test

NBEO - National Board of Examiners in Optometry Binocular Vision and Pediatrics Questions and Answers