PGH Basic Course 2014

Basic Pediatric Vision Exam

Alvina Pauline D. Santiago, MDPediatric Ophthalmology & Strabismus

2007

Vision Assessment

Preverbal Age Group

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Visual milestones

• Birth Bright lights• 7 days vestibulo-ocular reflex• 3 mos transient fixation &

following• 6 mos fixation & following

even for distance• 2-3 y 20/30• 5-7 y 20/2

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Vision Assessment

• Fixation pattern• 3 mos: transient fix and follow• 6 mos: fix and follow

– “CSM” : central, steady, maintained– cover one eye– start distance fixation

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Fixation preference

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Profound Amblyopia

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Fixation Preference & Visual Acuity

• Central, steady, maintainedCSM 20/20-20/30

• CS, maintained briefly 20/40-20/60• CS, not maintained (NM)20/70-20/80• C, NS, NM 20/100-20/200• Not C, Eccentric </= 20/300

Optokinetic (Catford) drum

• Fast saccades• May be calibrated

based on cycles per degree

Preferential Looking

• Modified optokinetic flag

• Teller acuity cards or its derivative

• Facial targets

Teller acuity cards

Forced Choice Preferential Looking Tests (FPLs)

School age child

• Not infants and toddlers• Preschool 3-6 years• Regular School 7-12• Adolescent 13-18

Vision testing

• Quantifiable• Depends on patient discrimination• Depends on examiner ability to interpret

response• Standard: Snellen acuity: optotype• Psychophysical tests: test interpretation

subjective measured by patient’s ability to communicate recognition to examiner

Preschool

• Short attention span• Inability to sustain interest• Language and communication barriers• Cultural and social limitations

Preschool Tests

• Detection acuity tests– Stycar graded balls (Sherian 1973)– Catford drum (Catford & Oliver 1973)– Dot visual acuity test

• Recognition acuity test– Direction oriented: Illiterate E, Landolt C– Picture charts– Letter charts

Vision Assessment: 3-6 years

• Allen pictures: cultural bias• Sheridan Gardner or HOTV/HOTEX• Illiterate E / tumbling E / E game• Landolt C• Snellen numbers, letters

– kids memorize!

Visual Acuity Testing

• Test Charts– HOTV / HOTEX– Tumbling “E” Game– Landolt C– Picture Charts

Illiterate/Preverbal Charts

Landolt C Tumbling E

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HOTV Charts

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Lea Charts

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Grating vs Snellen Acuity

• Grating acuity (cycles per degree)

• Snellen acuity (visual angle)

• Grating overestimates Snellen

Limitations of Optotype Test

• Snellen acuity unreliable before age 6-8• Not all children will know alphabet &

numbers• Single optotypes may overestimate linear

acuity

Normal Visual Development

Development of Visual Acuity

Susceptible Period

• Most sensitive first 2-3 years

• Decreases until age 6-7 years (12? 18?)– complete visual

maturation– retinocortical pathways

and visual centers resistant to abnormal visual input

7-12 years

• Significant number still will not express poor vision

• Easy to perform Snellen linear acuity testing

13-18 years

• Will verbalize a visual problem

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Vision Assessment

Non/Pre Verbal

OKN Drum FPLOKN Flag Teller

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Vision Assessment

Picture Charts HOTV SNELLEN

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Laser vision ;-)

Vision Assessment: Nystagmus

• Binocular near vision test– allow patient to assume own distance– test at standard near distance– check head posture– VA in forced primary

• Binocular distance vision• Monocular distance & near vision

Vision Assessment: Nystagmus

• Monocular occlusion– many will increase nystagmus

• Remote occlusion• Sufficient fogging: know refraction!• Neutral density filters• AO vectograph testing• Translucent occluder

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Random dot stereograms

• 2 plates of randomly displayed dots, one plate to each eye

• Shape of figure displaced horizontally relative to other plate

• No monocular cues• Normal may fail

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Sensory Tests & Visual Acuity

Circles Seconds of Arc VA9 40 20/258 50 20/307 60 20/406 80 20/505 100 20/604 140 20/703 200 20/802 400 20/1001 800 20/200Donzis 1974

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Thank You!