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25 Cards in this Set
- Front
- Back
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Child development (5) |
1. Prenatal: time from conception to birth
2. Infancy: from 18-24 months
3. Early childhood: end of infancy to 5-6 years (pre-school years)
4. Middle and late childhood: 6-11 years (elementary school year)
5. Adolescence: transition from childhood to early adulthood (12-19 years) |
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Theme in child development (3) |
1. Nature and Nurture - nature: biological inheritance, gene received from the parent - nurture: wide range of environment, both physical and social that influence the development (including the prenatal period)
2. The active child - children action contribute to their own development - e.g. choices in attentional pattern, language use and play
3. Continuity/ discontinuity - continuity: development is a continuous process of small change (like growing tree) - diacontinuity: development is a series of sudden discontinuous change (like transition from caterpillar to butterfly) |
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Theory of development (4) |
1. Sensormotor stage (Birth to 2 years of age) - coordinating sensory experience with physical action - progress from reflexive, instinctual action at birth to the beginning of symbolic thought
2. Preoperational stage (2-7) - words and images - increase symbolic thinking - connection of sensory information and physical action
3. Concrete operational stage (7-11) - reason logically about concrete event - classify objects into different sets
4. Formal operational stage (11+) - more abstract, idealistic and logical way |
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Implications of child development process (3) |
1. Genetic transmission of disease and disorder
2. Development delay issue, taking reference to development process
3. Screening vs surveillance (monitor) vs clinical examination |
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Importance if early visual assessment and intervention (4) |
1. Motor development 2. Social and communicative development 3. Emotional development 4. Cognitive development Children with severe visual impairment: development emergency |
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Development of the eye and visual pathway (4) |
1. Ocular components 2. Retina 3. Visual pathway 4. Visual function |
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Normal growth of the eye (2) + Newborn vs adult (3) |
1. Rapid growth in first 2 years - axial length: 82% of final size at 1 year - lens flatten - corneal radius lengthen 2. Slow down till puberty - axial length achieve adult size by 13 year Newborn vs adult - axial length (mm): 17 vs 24 - corneal horizontal (mm): 10 vs 12 - radius of corneal curvature (mm): 7 vs 7.9 |
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Iris change with age (3) |
1. Infant: steel gray eyes (Caucasian)/ light brown eyes (Asian) - lack of iris pigment
2. First 6 months: iris pigmentation increases - darkening of iris colour
3. 6-9 months: final eye color develop (more pigment added through 12 months) |
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Pupil change with age (3) |
1. Birth: dilator muscle poor developed 2. Infant: pupil is miotic 3. 6 month: normal size and function |
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Cornea at birth (3) |
1. Corneal curvature and anterior chamber: steep and deep
2. Corneal diameter: - normal: 10-11 cm - microcornea: <9 cm - macrocornea: >11.5 cm
3. Corneal clarity: rule out congenital glaucoma with cloudy cornea |
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Lens (1) and sclera (2) at birth |
Lens: 1. lens power is greater (compensate short axial length)
Sclera: 1. less rigid at birth 2. thinner and translucent - appear blue sclera (appearance of choroidal melanin) |
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Retina change with age Birth (5), 8 month, 9 month, 45 month, from infant to adulthood (3) |
Birth: 1. Vessel tortuous 2. May have retinal hemorrhage (sudden resolve without problem) 3. Light colour of retina and optic nerve 4. Small cup size 5. Overall axial length is short
8 month: vasculature complete to nasal ora and temporal equator
9 month: vascularized to temporal ora
45 month: fovea can be differentiated
From infant to adulthood 1. Retina continue to expand toward peripheral, double the retinal area (by spreading out the cell)
2. Completion of foveal pit, much thinner part than the rest of the retina (ganglion cell layer move to the side)
3. Increase cone density at fovea - thinning and lengthening of cone outer segment - more tightly packed centrally |
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Visual pathway change with age (2) |
1. From birth to 8 months - visunal cortex - number of synapse increase (double)
2. First 2 years: - optic nerve, optic tract fibre - myelin sheath continue to develop - thickness increase - improve synapse transmission |
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General development 2-4 months (4) |
1. Visual tracking 2. Social interaction 3. Hearing 4. Motor skills |
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Visual behavior observation 4 weeks (4), 6 weeks (7), 2-6 months (4), 6-12 months (4), 12-18 months (2), 3 year (2) |
4 weeks: 1. Look vacantly 呆望 2. Look at face and light 3. Head sag forward (down) 4. Eye not synchronized 同步 with head
6 weeks: 1. A child has useful sight and is eager to use it 2. Bright, bold target 3. Preference for a face like stimulus 4. Blink to sound or bright light 5. Blink less frequently 6. Follow slow moving object with small jerky eye movement 7. Two eyes mainly aligned with occasional inward turn
2-6 months 1. Smoother eye movement (eye mobility improve) 2. Visual tracking with head movement (look at slowly moving target) 3. Explore the hand and interested at face (fine motor skills improve) 4. Fewer eye turn in
6-12 months 1. Visual tracking with less head movement (eye follow moving toy 180°) 2. Good fixation and re-fixation for interested target 3. More attention to distance target rather than just arm length 4. Eye should be fully co-ordinated
12-18 months 1. Recognize objects, toys and pictures and point them out 2. Use both hand to bring object close and enjoy exploring toys
3 year 1. Visual explore, inspect without touching 2. Feed self well, can name colour and body part, can button up 緊扣 |
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Ocular reflex in infant (4) |
1. Blink reflex - rate is less frequent - blink to loud noise/ sudden light - not blink to an coming visual stimulus
2. Corneal response (to touch) is absent - presence at 3 months
3. Pupillary light and near response present (Miotic pupil/ sluggish reflex) - smaller and more sluggish than in adult - under development of dilator muscle
4. Optokinetic nystagmus present - when stimulus moves slowly enough and show binocularity - fast phase is less frequent than in adult - <3 month: asymmetric OKN is present, monocular OKN only in temporal to nasal direction - symmetrical OKN development show binocularity |
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Visual function (7) |
1. Visual acuity 2. Contrast sensitivity 3. Accommodation 4. Eye movement 5. Convergence 6. Stereopsis 7. Fusional vergence |
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Visual acuity (3) |
1. Infancy - measured by preferential looking (PL) with black and white grating
2. Older age - measured with picture/ letter target familiar to child
3. Different tests are not comparable - depend on technique and target
Newborn: 6/300 (6/120) 1 month: 6/200 (6/120)-6/90 3-6 months: 6/60-6/36 9 months: 6/36-6/24 1 year: 6/24-6/12 2 years: 6/12-6/9 3 years: 6/9-6/6 |
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Response to grating (4) |
1. 1 month: 0.55+-0.70 cpd (1.74+-0.21 logMar)
2. 3 months: 3.11+-0.54 cpd (0.98+-0.16 logMar)
3. Improvement in detection grating acuity value during the first 3 months of life in cpd and logMar
4. No evidence to converse back to recognition acuity value - infant fovea is not like adult fovea |
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Contrast sensitivity (3) |
1. Poor CS at birth, develop rapidly over first 1-3 months
2. Sensitivity to lower spatial frequencies (large target) develop faster than high one - low vs high: 6 months vs 3-4 year
3. Faster development in low contrast - enhance social and communication skill development in Infant - facial expression: fast moving low contrast shadow - eye: large detail at intermediate and high contrast |
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Accommodation (4), Hainline 1992 finding (3) |
1. 9 weeks: start accommodation (Banks 1980)
2. <2 months: fixed at 30cm (Hainline 1992)
3. 3-4 months: accurate accommodation (Hainline 1992)
4. Most baby is under accommodation - 10 years: accommodate accurately within 0.5D - esp. with disabilities such as Down’s syndrome/ cerebral palsy
Hainline 1992 1. Measured accommodation by paraxial photorefraction with doll at different distance 2. 26-45 days: 50% infant can accommodate accurately 3. 46-60 days: 70% can accommodate accurately 4. Infant can accommodate to 19cm - around baby eye to mum face during feeding |
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Eye movement (4) |
1. Fixate on a stationary object
2. Move the eye towards stimulus at periphery of the visual field
3. Smooth pursuit - start at 1 month (6-8 weeks): - only for very slow speeds target (10 degrees per second) - greater improvement by 4 months
4. Saccade - <7 month, a series of small eye movement - head movements are used to supplement the saccade (3 months: head and eye movement coordination as adult) - for fixate an object of interest - for target with quick movement
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Convergence (3), Vergence movement (3) |
1. 25 days: start convergence 2. <1 month: bifoveal fixation on light at 10-12 inches 3. >2 months: like adult - show greatest variability in vergence Vergence movement 1. 3 months: 70% accurate convergence and divergence movement (Aslin 1998) 2. 6 months: distinctive fusional vergence movement (McKenzie 1991) 3. 4-6 months: consistent convergence ability and fusional vergence movement |
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Stereopsis (3), Scotoptic vision (4) |
Stereopsis 1. 3.5 months: onset 2. 5-6 months: stereoacuity 1 min of arc 3. 3-4 years: reach adult Scotoptic vision 1. Reduced B wave ERG - reduced rhodopsin in infant 2. First 3 months: rod response mature rapidly 3. Next 9 months: slow down 4. 1 year: reach adult |
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Overall development of visual system (7) |
1. Newborn: - VA 6/120, 6/6 at 6 years - fixation reflex presence (full term baby)
2. 2/3 week: mono fixation
3. 6-8 week: bino fixation, conjugate eye movement
4. 3 months: conscious fixation
5. 5 months: convergence, some fusion, accommodation
6. 1 year: good fusion
7. 1.5 year: accommodation/ convergence working together |
