PGH Basic Course 2016

Basic Pediatric Vision Exam

Alvina Pauline D. Santiago, MD Pediatric Ophthalmology & Strabismus

Vision Assessment

Preverbal Age Group

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

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

Fixation preference

Profound Amblyopia

Fixation Preference & Visual Acuity

•  Central, steady, maintained CSM 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: Sloan linear 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 (Sheridan 1973) – Catford drum (Catford & Oliver 1973) – Dot visual acuity test

•  Recognition acuity test – Direction oriented: Illiterate E, Landolt C – Picture charts: Allen, Lea® Symbols – Letter charts: Snellen, Sloan

Vision Assessment: 3-6 years

•  Allen pictures: cultural bias

•  Sheridan Gardner or HOTV/HOTEX

•  Illiterate E / tumbling E / E game

•  Landolt C •  Lea® Symbols and

Numbers •  Snellen numbers, letters

–  kids memorize!

•  Sloan Letters http://www.keeler.co.uk/images/products/nearvisionsheridan2_250x250.jpg

Visual Acuity Testing

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

Lea® Symbols

Allen picture cards

Illiterate/Preverbal Charts

Landolt C Tumbling E

HOTV Charts

Lea® Charts

Lea® Charts

Grating vs Snellen Acuity

•  Grating acuity (cycles per degree)

•  Snellen acuity (visual angle)

•  Grating overestimates Snellen

Limitations of Optotype Test

•  Letter or number acuity (e.g. Snellen or Sloan) unreliable before age 6-8

•  Not all children will know alphabet & numbers

•  Single optotypes may overestimate linear acuity

https://toddlerglasses.files.wordpress.com/2009/07/eye-charts-358x338-allaboutvision.gif?w=300

Sloan letters

http://www.eyesfirst.eu/media/catalog/product/cache/1/image/640x/040ec09b1e35df139433887a97daa66f/5/2/52098_etdrs_tafel.jpg

Sloan vs. Snellen Charts

https://www.schoolhealth.com/blog/selecting-an-eye-chart-sloan-letters-or-snellen/

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 Sloan linear acuity testing

13-18 years

•  Will verbalize a visual problem

Vision Assessment

Non/Pre Verbal

OKN Drum FPL OKN Flag Teller

Vision Assessment

Picture Charts HOTV Snellen / Sloan

http://www.uniroma2.it/otticafp/vafig1.gif

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

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

Sensory Tests & Visual Acuity

Circles Seconds of Arc VA 9 40 20/25 8 50 20/30 7 60 20/40 6 80 20/50 5 100 20/60 4 140 20/70 3 200 20/80 2 400 20/100 1 800 20/200 Donzis 1974

Thank You!