Lecture 4 Flashcards
When should convergence talk place in a child
Ages 1-3 months
1 month: can be done
2 month: Consistent
3 month: without delay
How to test NPC on kids?
Same way as adult, but use interesting target.
cm, lateral canthus, OU open.
Usually would ask adults to tell you when it breaks, but do not do this with kids. Watch their eye and see if it swings out.
Normal NPC values
Normal: 5cm/7cm. Lower vales are good (were able to get closer to patient before double. Ex: TTN). Lower values are bad. Mean you were further away from pt when they doubled. May need VT or prism.
Subjective phoria test
Subjective measurement of binocularity using Von Grafe. Cannot differentiate from a phoria vs intermittent trope behind phoropter.
12BI OD, 6 BU OS
Headlights on a car for vertical.
Buttons on a shirt for horizontal.
Show kids with hands fist and have them tell you when to stop once hands are aligned.
Verenge testing purpose
To test fusional vergence amplitude with prisms.
Vergence works with accommodation system always. Shows quality of binocular function.
Done at distance and near- we are doing a lot more near work now a days.
3 values:
Blur, break, recovery
Can do this in the phoropter (smooth with risley bar) and using a prism bar (step vergences)
Prism bar vergences/step vergences
- Purpose
- how to do it
- Normal values at near
Can observe objective eye movements, can also ask pt when target gets double and then becomes single again.
Normal:
Near base in: X/12/7
Near base out: X/23/16
Smooth vergence in phoropter with risley prism. Morgan’s norms at distance and near
Distance BI: x/7/4
Distance BO: 9/19/10
Near BI: 13/21/13
Near BO: 17/21/11
Worth’s degrees of fusion
1st: Simultaneous perception. Fusable, but no common features. Lion and cage. Both eyes are working, images may not be fused.
2nd: Flat fusion. Both bunnies with similar features + some different. 1 has flower, 1 has tail. Both eyes working, single image formed. No depth.
3rd: Stereo. Depth.
When does stereo emerge
at 3-4 months. By 6 months, almost 100% of infants appreciate stereo
Not demonstrable under 8 weeks.
Ex: Visual Cliff experience
Bernell Functional Binocular Assessment Test
Bernell Functional Binocular Assessment Test (previously the keystone) Good for young, non verbal patients.
Not random.
Pt wears red/green glasses at 20-30 cm. See if child reaches for the target. If they touch the page, they don’t see it.
Examples of stereo testing with infants
Bernell Functional Binocular Assessment Test
- Good for non verbal children or adults
- Red/green glasses. Child will reach out to grab image.
Smile
- Polarized glasses.
- Preferential looking test. Does child look at smile?
Lang
- No glasses worn
- Ask child to point/look at/name figure they see
Random Dot E
- Polarized glasses
- Toddler/preschoolers: have 3 cards. Preferential looking
- Preschool/school aged: Global matching (shapes) and local with ran dot background (Wirt circles, animals) stereo.
Tutmus fly/butterfly
-More gross
Smile Stereo testing
Preschool aged children.
Polarized glasses.
Preferential looking test. Does child look at smile?
Lang stereo testing
Does not require polarized glasses. Ask child to point to or look at figure. Pt can name if they see it.
Random Dot E for toddlers/preschoolers
Polarized glasses
Preferential looking- have 3 cards. Raised E, stereo E, and blank card.
Random Dot E for preschoolers/school aged
Polarized glasses Global stereo (shapes) matching. "See this circle on the front of the book? Can you find the circle inside?"
Local stereo (Wirt circles and animals) with random dot background.
What does the flashlight test determine?
- Testing distance
- When to use it?
Determines binocularity, not stereo. 2nd degree fusion.
- 16 inches/40cm or 20 feet (distance or near)
- If pt has strabismus at distance, decrease in VA in 1 eye without significant Rx, complaint of double vision.
Procedure to test binocularity using 3 figure flashlight
3 figures on the flashlight: Red dancer, green elephant, and white ball that will appear color of dominant eye or a mixture.
-Red/green glasses. Red over right eye.
-Can be done in bright or dim lighting. (Tests for deepness of suppression)
Suppressing in bright lighting: new binocularity issue.
Suppressing in bright + dim lighting: Deep suppression issue.
-Ask what patient sees.
Procedure to test binocularity using 4 dot flashlight/4 shape flashlight
- Red/green glasses. Red over right eye.
- 2 green dots, one red, one white
-Can be done in bright or dim lighting. (Tests for deepness of suppression)
Suppressing in bright lighting: new binocularity issue.
Suppressing in bright + dim lighting: Deep suppression issue.
-Ask how many dots the patient sees
4 dot flashlight/4 shape flashlight results. What does each mean?
- 2 red
- 3 green
- 4 dots (no strab)
- 4 dots (with strab)
- Diplopia- 2 red/3 green
if red is on right or left what does that mean?
- OS suppression
- OD suppression
- 2nd degree fusion. What we want!
- Anomalous correspondence. Rare. Even tho eyes are turning, brain thinks they are straight.
- Will see 5 dots: 2 red and 3 green.
- Red on right= uncrossed= eso
- Red on left= crossed= exo
Testing of saccades and pursuits
- Purpose
- At what age do you test?
- What symptoms/complaints may warrant you to test saccades and pursuits?
Purpose: Eye movements important for reading and sports.
- Start testing at school ages (5 and up)
- pt complaining of losing place while reading (saccades), athletes, Brain injury pts.
Pursuits in infants
They have the ability to make pursuits, but not very well or very consistently. Depends on testing conditions
Testing of pursuits
- What do you use?
- Which directions do you go in
Wolff want or similar target
Broad H (Horizontal, vertical) Diagonal Circles Z axis Start/stop Speed change
Infants age 1-2 months doing saccades. Findings
Initial saccade in the wrong direction
Succession of saccades (multiple steps)
Longer latency- longer to get started./
When are saccades adult like
13 months. Longer than conversion!
Different tests for saccades
Chairside: Wolff wand or similar targets. Pen and pencil.
Test horizontal, 12 inches apart.
Paper tests: DEM, King Device. Child is timed and compared to average for age.
Eye tracking: Readalyzer, right eye.
NSUCO is the standardized way to measure
Ocular motor skills. It judges multiple aspects for each probe:
Ability, accuracy (re-fixations, over or under shoots) head movements, body movements.
Key: DO NOT say anything about holding head steady or not moving their head.
Have them make 10 saccades from 1 wolff want to the other.
Then have them follow 2 circle pursuits clockwise and 2 counter clockwise.
Then look at scarring card. (level 1 to level 5) Level 1 is poor, 5 is efficient.
Trend of NSUCO pursuits and saccade scoring
Boys worse than girls
NSUCO scoring card assess which 4 things
Ability
Accurancy
Head movement
Body movement
