Exam 1 Flashcards
What ratio of pediatric patients will develop amblyopia?
1/30
What ratio of pediatric patients will develop strabismus
1/25
What ratio of pediatric patients will show a significant refractive error?
1/33
What ratio of pediatric patients will show eye disease?
1/100
How commonly does a vision disorder cause disability in the United States?
4th most common!
What is the most common handicapping condition of childhood?
Visual problems
What percent of children aged 9-15 need glasses? Of this percentage, how many of those children have glasses?
20% need glasses
10% of the 20% have them
How likely are pediatric patients to have had a comprehensive eye exam by age 6? 6-16?
By age 6: 14%
Ages 6-16: 31%
Explain how common vision screenings are by pediatricians. What is a pediatrician’s vision screening?
66% of pediatricians do vision screenings
A vision screening is: “When 10 seconds are taken to evaluate a patient’s vision by trying to get the patient to cooperate”
How common is it for a patient to fail a vision screening and have the parents unaware?
50% of children who have failed a vision screening have parents who are unaware 2 months later!
What are some of the primary benefits of pediatric eye exams? What are some secondary benefits?
Primary Benefits:
- Early detection and treatment of amblyopia
- Early detection and treatment of strabismus
- Early detection of significant disease
Secondary:
- Looks good for our profession, more recognition of contribution to public health
- Importance of vision in normal development can be stressed
What are the different stages of pediatric patients?
Premie: Less than 37 weeks. Neonate: 0-28 days Infant: 29 days - 11 months Toddler: 1 - 3 years Child: 3- 13 years Adolescent: 10-19 years
Explain adjusted age with premies.
Premies are born at less than 37 weeks and this can affect developmental milestones. Adjusted age is calculated by determining the time between birth and the due date to appropriately scale developmental milestones
What are the AOA frequencies of examination for different age groups?
A = Asymptomatic R = At risk
Birth-24 months:
A: 6 months
R: 6 months/as recommended
2-5:
A: 3 years
R: 3 years/as recommended
6-18:
A Before 1st grade, then every 2 years
R: Annually/as recommended
18-60:
A: Every 2 years
R: Every 1-2 years/as recommended
61+:
A: Annually
R: Annually/as rec
What are some purposes of an infant eye exam?
- Optimize visual function that is important for the development of the infant
Determine if the eyes are straight, healthy, and can the baby see? Do you need to intervene to:
a) improve vision
b) prevent/treat an eye turn
c) prevent amblyopia
d) prevent/treat an ocular health issue
When is the best time for a pediatric eye exam?
The best time is in the morning or after a nap. Patients will not be as well behaved if the appointment is during the scheduled nap time!
How do you navigate an infant eye exam?
Base your judgment and prescribing on observation, reflexes and gauge your expectations. Don’t expect perfect vision, just make sure basic functions are present
What is the assessment protocol for pediatric eye exams?
- VA:
Fix and follow
Richman Face Paddles
Vertical Prism - RE:
Mohindra
Cyclo
3. BV: CT Vertical Prism Bruckner Hirschberg
- Motility:
EOM
5. Health: Visual field Pupils Gross external Dilated internal
What are some important questions to ask regarding case history for infant eye exams? (6)
Normal developmental milestones met?
Full-term pregnancy? (less than 37 weeks is preterm)
Normal birth weight?
Problems during pregnancy/delivery?
Medical issues?
Any current therapies or medical interventions?
When are three important ages that the average pediatric patient should have an eye exam?
Before age 1
At age 3
Before 1st grade
What percent of pediatric patients have never had an eye exam?
70%!
What is a good range of RE for an infant?
Plane - +4.00D
What are the two main objectives for VA’s in pediatric patients?
Quantitative: What is the acuity threshold? OD? OS? OU?
Qualitative: Are they adapting, using both eyes?
What are 3 ways to perform VA on pediatric patients?
Fix and follow
Resistance to occlusion (Will get fussy if having to use “bad” eye)
Vertical prism (Eyes will jump between if using both eyes)
What are three ways you can quantify VA on pediatric patients?
- Detection acuity with Cardiff cards
- Resolution with lea paddles or teller paddles
- Recognition by naming/matching
What age/situations would preferential looking be optimal for?
0-12 months or developmentally delayed.
The child will look at black/white lines instead of grey. You continue to decrease contrast until the child alternates fixation (cannot see grating anymore)
What is the VEP?
Visually Evoked Potential
Measures electrophysiological response to light. This is more reliable than preferential looking but is more expensive
What is the difference between static and dynamic ret?
Static occurs when fixation is at optical infinity and is relaxed
Dynamic involves near accommodative abilities
Explain the Mohindra Technique.
Near ret performed in a dark room at 50cm. If performed monocularly, subtract 1.25D from neutralizing lens. If performed binocularly, subtract 0.75 - 1.0 D from neutralizing lens
Autorefraction has minimal value without ___________.
cycloplegia
What are the expected results for Hirschberg?
Equal reflexes that are ~+1.00mm nasal
1mm = 20^
What are some rules of thumb for birth weight in children?
Should double by 5 months
Should triple in 1 year
Should quadruple in 1.5 years
What is the rule of thumb for the length of a newborn?
Should increase 1.5x in 1 year
What are the body structure proportions as a person develops from birth to adolescence?
Head should increase 2x (Head contributes 1/4 of birthweight, 1/12 of weight at maturity) Trunk should increase 3x Upper extremities should increase 4x Lower extremities should increase 5x
What are tissue proportions as a person develops from a newborn to an adult?
Muscle:
Neonate -> 20%
Adult ->45%
Internal Organs:
Neonate -> 15%
Adult -> 10%
Nervous System:
Neonate -> 15%
Adult -> 3%
What point in embryological development is the eye discernable? When are structures identifiable?
The eye is discernable in 3 weeks
Structures are identifiable by 5 weeks
What are the two goals of eye development?
Create a transparent optical system
Develop neural transmission of information
What is the master control gene for eye formation?
Pax-6
What occurs in the embryonic period? When is the embryonic period?
- Mesoderm surrounds the optic vesicle (day 26)
- Mesenchyme fills the optic cup with vitreous and supplies early posterior chamber with blood supply
- The early hyaloid system is formed by the end of the second month
Embryonic period is Up to 9 weeks
When is the fetal period?
Fetal period is 9 weeks of gestation (63 days) to birth
Abnormalities in the fetal period result in _______ abnormalities whereas abnormalities in the embryonic period result in _______ abnormalities.
Fetal: functional problems
Embryonic: Structural
What occurs before the eyes open in the gestational period?
Retinal structures have differentiated and formed. Axons connecting retinal to LGN to cortex have connected
When do axons enter the LGN from the optic tract?
7-8 weeks
What is Hebb’s Law?
Neurons that fire together wire together
Explain LGN formation and the probability of vision problems.
If LGN is formed and then there is a problem, likely there will be a significantly lower risk of vision problems occurring. If a problem is before LGN forms, there is a higher chance of vision problems.
When are the visual cortex cells developing?
6 weeks to 5 months
Which layer of the cortex is formed first in development?
Innermost layer
When do axons from the LGN reach the cortex?
11-13 weeks
When are synapses made into the cortical plate?
23-25 weeks
When do ocular dominance columns arise?
AFTER the eye is open
Structural abnormalities are due to insult in the _______ period and functional abnormalities are due to insult in the ________ period. (REPEAT CARD)
Structural: Embryonic
Functional: Fetal
What are the three phases of axial length?
0-2 years: 4mm in year 1 and 2mm in year 2
2-5years: 1mm
5-13 years: 1mm
What is the power of the cornea at birth and what is the power at 6 months? What is the corneal power at 12 months?
Birth: 52D
6 Months: 46D
12 Months: 42-44D
What is the diameter of the cornea at birth? As an adult?
Birth: 10mm, +/- 0.5mm
Adult: 12mm
When does OKN become apparent? (Pursuits/Saccades)
34 weeks
Which gaze, horizontal or vertical is established at birth? Which takes 6 months?
Birth: Horizontal
6 Months: Vertical
When do Accommodation and NPC develop?
3 months
When are melanin deposits evident on the iris?
6-12 months
When is the pupil reactive?
31 weeks (2 months before birth)
What is a normal pupil size in an infant -> 2-year-old?
5mm