Pediatric Vision Evaluation and Screening - VanderMuelen Flashcards
When does normal vision develop?
During infancy and childhood
Focused visual stimuli are critical to:
Normal sight development Early detection and correction of vision problems
Visual Development- a) Newborns follow: b) By 2-3 months infants follow: c) By 4-6 months:
a) Faces b) Lights and high contrast objects c) Visual system matures (20/40)
Symptoms of Potential Eye Problems
Rubbing the eyes Shutting or covering one eye Tilting or turning head Squinting Inability to see distant objects clearly Bumping into walls or objects Holding objects close to see Crossing of eyes
Red Reflex
Screen for posterior segment (RETINA) abnormalities or corneal opacities
3 Categories of Visual Impairment
Neurological abnormalities that mimic vision impairment Vision impairment with Nystagmus Vision impairment without Nystagmus
Neurological Abnormalities mimicking visual impairments
Developmental delay or autism - poor visual fixation
Poor occulomotor control - cerebral palsy or congenital motor apraxia
define Nystagmus:
rhythmic oscillation of the eyes
usually horizontal, but can be vertical or rotatory
Visual Impairment with Nystagmus
any disorder of the **bilateral anterior visual pathways (cornea to geniculate body) **that affects the visual acuity under the age of 2 almost always results in nystagmus
ex: Congeital cataracts, anterior segment anomalies, retinal degenertation/dystrophy, optic nerve anomalies
Visual Impairment without Nystagmus is (almost always) caused by-
cortical visual impairment or delayed visual maturation
abnormality of the posterior visual pathways
- Hypoxia
- Hemorrhage
- Cerebral malformations
- Metabolic disorders
- Infections
define Amblyopia:
lazy eye - loss of one eye’s ability to see details
in the absence of proper visual input from the visual pathway the brain “shuts down” the vision in the affected eye
Amblyopia causes
prolonged abnormal visual experience
- distortion of normally clear retinal image (cataracts, refractive difference between eyes)
- abnormal binouclar interaction (Strabismus)
Amblyopia treatment
address refractive errors
visual rehabilitation - patching eyes, fogging the good eye with chemicals or lenses
define Strabismus:
misalignment of one eye relative to the other in one or more positions of gaze
Manifest Strabismus (Tropia)
occurs spontaneously
may be constant or intermittent
examiner cannot induce it
Color Blindness
80% of white-males have some red-green deficiency
familial
tested using Ishihara tests
