lecture 3 normal visual development in children and adolescents

Question 1

what are the 3 different types of acuity?

Answer 1

1) resolution acuity (grating acuity)
2) recognition acuity (various vision charts)
3) vernier acuity (hyperacuity)

Question 2

which type of acuity testing method measures how well you can align two bars

Answer 2

vernier acuity (hyperacuity)

Question 3

what are 3 ways to assess resolution acuity (especially for non verbal patients)

Answer 3

VEP (visually evoked potential), OKN (optokinetic nystagmus), PL (preferential looking)

Question 4

which acuity testing method measures the rapid saccades of a person veiwing vertical lines that get thinner and thinner until the patient no longer detects the contrast?

Answer 4

OKN (optokinetic nystagmus)

Question 5

what are the 3 types of stimuli for VEP testing?

Answer 5

1) luminance on-off flashing
2) pattern on-off
3) pattern reversal

Question 6

(Tor F) OKN may not give a true reading of visual acuity since it works on a lower visual pathway (one wired to oculomotor rather than primary visual cortex)

Answer 6

true, VEP measures visual pathway up to primary visual cortex

Question 7

In a VEP recording, how do you measure latency?

Answer 7

latency is how long to the first response

Question 8

Visual Acuity starts at _____ at birth and can reach _____ as early as 6-8 months

Answer 8

20/600, 20/20

Question 9

What is the behavioral method for V. A. testing?

Answer 9

PL (preferential looking), when you present a pattern and non-pattern and observe the baby noticing the pattern stimuli. When the baby no longer prefers to look at the pattern, the step before is the V.A. limit

Question 10

what is the Teller acuity card?

Answer 10

This is a preferential looking V.A. method used on babies. there are 7 large plates that have one blank side and one side with vertical stripes. each card has smaller spaced lines than the last. they also have a peep hole behind so you can observe the patient looking toward the pattern stimulus until the lines get so small that they blend and no longer create a pattern. then the baby will stop directing his/her focus on the pattern.

Question 11

what is the lea grating paddles? how are they more advantageous than teller acuity cards and how are they not?

Answer 11

The lea grating paddles are similar to the teller acuity card but smaller. they are cheaper and easier to travel with than the teller acuity cards, however, they do not cover your face and babies tend to get distracted by looking at your face

Question 12

what is the cardiff acuity test?

Answer 12

This is a preferential looking V.A. method used on babies who are a little older, like 1 to 2 years old. older babies tend to be bored with the stripes on the teller and lea grating tests so the Cardiff introduces familiar shapes like cars and animals.

Question 13

What is the most objective VA test? and 2nd most?

Answer 13

VEP is the most objective. OKN is next in line. (preferential looking is considered subjective)

Question 14

At what would you expect Objective vs. subjective testing to reach adult levels?

Answer 14

objective (VEP and OKN) @ 6-8 months, subjective (PL) @ 3-5 years.

Question 15

what is the MOST IMPORTANT limiting factor for VA development in infants? (why are babies not born with 20/20 vision)

Answer 15

foveal cone immaturity. as well as incomplete myelination of the optic pathway and cortical immaturity.

Question 16

When testing VA in a normal 8 month baby using the VEP method vs FPL method, you can expect the VA to be what

Answer 16

vep=20/25 FPL=20/100

Question 17

Between FPL and VEP methods, which is a more accurate assessment of higher level processing?

Answer 17

FPL is because this is behavioral and it takes into consideration the combination more aspects of vision and comprehension.

Question 18

(T or F) a newborn cones are short at birth and both the outer segment and inner segment axons elongate

Answer 18

true

Question 19

In monkey primary cortex development when are ocular dominance columns present?

Answer 19

3 months (humans is 6 months)

Question 20

cortical development is also a limit factor in VA in newborns. At what age does synaptic connectivity skyrocket?

Answer 20

6-8 months

Question 21

incomplete myelination of the optic pathway is also a limit factor in VA in newborns. how long does it take to complete myelination?

Answer 21

2 years

Question 22

vernier acuity (hyperacuity) is largely based on what?

A) oculomotor function
B) accomodative function
C) cortical processing
D) cognitive processing

Answer 22

C) cortical processing

Question 23

why is vernier acuity also known as hyperacuity?

Answer 23

it is 10 times better than grating acuity

Question 24

at what age does vernier acuity reach adult levels?

Answer 24

6-8 years

Question 25

at what age is the peak of emmetropization?

A) 1 year old
B) 3 years old
C) 6 years old
D) 10 years old

Answer 25

C) 6 yrs old

Question 26

emmetropization is a process by which the refractive condition of the ye, regardless of wheather it is initially hyperopia, myopia, or astigmatism, centers on a refractive range around low _____ to _____

a) hyperopia, emmetropia
b) myopia, emmetropia
c) hyperopia, myopia
d) myopia, hyperopia

Answer 26

a) hyperopia, emmetropia

Question 27

what is the prevalence in astigmatism in infants?

A) 100%
B) 75%
C) 50%
D) 0%

Answer 27

C) 50%

Question 28

most infants are _____

A) myopic
B) hyperopic
C) astigmatic
D) blind

Answer 28

B) hyperopic (about +2.00)

Question 29

The induction of myopia is mediated by _____ _____

Answer 29

retinal blur (corneal opacities and cataracts can cause axial elongation)

Question 30

If a 5-6 years old has greater than or equal to +1.50D of hyperopia, you can expect he/she will be_______ at 13-14 years old

A) myopic
B) hyperopic
C) emmetropic (-0.50D to +1.00D)

Answer 30

B) hyperopic

Question 31

If a 5-6 years old has hyperopia between +0.50D and +1.25D, you can expect he/she will be_______ at 13-14 years old

A) myopic
B) hyperopic
C) emmetropic (-0.50 to +1.00)

Answer 31

C) emmetropic (-0.50 to +1.00)

Question 32

If a 5-6 years old has less than +0.50D of hyperopia, you can expect he/she will be_______ at 13-14 years old

A) myopic
B) hyperopic
C) emmetropic (-0.50 to +1.00)

Answer 32

A) myopic

Question 33

(T or F) prevalence of refractive error has little to do with ethnicity.

Answer 33

False, asians have the highest prevalence followed by hispanics. african american and whites have the lowest prevalence of myopia

Question 34

What does CLEERE stand for? what is it?

Answer 34

Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error study. A study that compared refractive error among different races.

Question 35

which ethnic group had the lowest prevalence for astigmatism?

Answer 35

african americans (asians and hispanics equally have the highest)

Question 36

when it comes to myopia progression which of the following statements are true?

A) myopia tends to not increase in school-aged children
B) myopia progresses at a rate of 0.25D per year until it ceases
C) the most important risk factor in myopia progression is alcohol abuse
D) the earlier the onset , the greater the myopia

Answer 36

D) the earlier the onset , the greater the myopia (myopia progresses at a rate of 0.50D per year)

Question 37

Which of the following is a factor in myopia progression?

A) gender
B) amount of near work
C) age
D) B and C only
E) all of the above

Answer 37

E) all of the above

Question 38

when it comes to hyperopic progression which of the following statements are true?

A) hyperopia tends to not increase in school-aged children
B) hyperopia progresses at a rate of 0.25D per year until it ceases
C) the most important risk factor in hyperopic progression is alcohol abuse
D) the earlier the onset , the greater the hyperopia

Answer 38

A) hyperopia tends to not increase in school-aged children

Question 39

What are the 4 visual function modalities and when do they reach adult level?

Answer 39

oculomotor=3-6 months
accommodation=3-4 months
convergence and fusion=22 weeks
stereopsis=6 months

Question 40

When you test a normal 3 year old patient’s visual acuity using Cardiff acuity card, what do you expect the visual acuity to be:
	A.	20/20
	B.	20/200
	C.	20/50
	D.	20/100

Answer 40

A. 20/20

Question 41

Which of the following statement about Optokinetic Nystagmus (OKN) is correct:
A. OKN relies on the same neural pathways as conscious visual perception.
B. OKN response relies heavily upon the infant/child’s cognitive ability.
C. Visual acuity measured by OKN method shows that children’s visual acuity reach adult level at age of 3-5 years old.
D. OKN can be present in a patient with severe damage to the primary visual cortex.

Answer 41

D. OKN can be present in a patient with severe damage to the primary visual cortex.

Question 42

By using the preferential looking methods to test the contrast sensitivity, scientists find that the overall function reaches adult level at age of:
	A.	4-6 years
	B.	7-9 years
	C.	12-14 years
	D.	3-5 years

Answer 42

B. 7-9 years

Question 43

Which of the following statement about contrast sensitivity development is correct?
A. Sensitivity to the high spatial frequency stimulus develops first.
B. VEP study shows that at 8 months, infant’s sensitivity to high spatial frequency stimulus reaches about half of the adult level.
C. Infant shows adult like sensitivity to low spatial frequency stimulus right after birth in the VEP study.
D. VEP study shows that at 10 weeks, infant’s sensitivity to high spatial frequency stimulus is similar to adult level.

Answer 43

B. VEP study shows that at 8 months, infant’s sensitivity to high spatial frequency stimulus reaches about half of the adult level.

Question 44

Vernier acuity becomes better than grating acuity at the age of:
	A.	12 months
	B.	24 months
	C.	1 month
	D.	4 months

Answer 44

D. 4 months

Question 45

When you test a normal 3 months old patient’s visual acuity using teller acuity card, what do you expect the visual acuity should be:
	A.	20/20
	B.	20/50
	C.	20/200
	D.	20/600

Answer 45

C. 20/200

1 month=20/600
3 month=20/200
6 month=20/100
12 month=20/50
3-5 yrs=20/20

Question 46

Which of the following statement about emmetropization is correct?.
A. It reaches the peak at about 2 years of age.
B. It develops towards a refractive range around low myopia to emmetropia.
C. It is a developmental process determined by the initially refractive condition of the eye.
D. Largest and fastest changes occur during the first 12 -18 months of life.

Answer 46

D. Largest and fastest changes occur during the first 12 -18 months of life.