Download Vision problems

NUR 584 Health Promotion and Clinical Prevention
Pediatric Special Topic
Objectives
Introduction
 Natural History
 Primary Prevention
 Secondary Prevention
 Tertiary Prevention
 Common Errors
 Emerging Trends

Introduction

Amblyopia
 Loss of vision due to inadequate visual
stimulation of the brain during cortical visual
development.
 Causes
○ Strabismus – Improper Alignment
○ Hyperopia – Far Sightedness
○ Astigmatism – Unfocused images on the retina
due to unequal curvative of the refractive surface
○ Cataract – Opacity of the lens
○ Eye Lid Hemangioma
○ Blepharoptosis – Dropping eye lid
Strabismus


Improper alignment.
Infantile Strabismus
 Appears before 6 months of age and usually associated with
family history. Referral if persists beyond 6 months of age.
 Constant fixation more likely to result in amblyopia of the eye
that is turned inward.
 May require surgical correction by age 2 if does not resolve.

Accomodative esotropia





Due to hyperopia (farsightedness).
May be intermittent or persistent, usually hereditary
Appears between infancy and 4 years of age.
Most noted when child is tired, ill, or looking into the distance.
Late-onset, constant exotropia is more worrisome – may
indicate ocular or central nervous system disease
Cataracts





Opacity of the lens
May be congenital or acquired.
1/4 are familial (autosomal dominant); 1/3 are
related to maternal infection during pregnancy
(rubella). Remainder are sporadic cases or
part of a congenital syndrome (Downs,
Turners) or systemic illness (galactosemia).
When the cataract diffuses light rays entering
the eye, it obstructs the transmission of clear
images onto the retina, resulting in abnormal
vision.
Significant cause of deprivation amblyopia.
Refractive Error

Myopia
 Nearsightedness – defect in ability to see
distant objects

Hyperopia
 Farsightedness – inability to see objects at

close range and can cause problems with
reading.
Unilateral hyperopia can lead to amblyopia.
Natural History of Visual System

Ability to focus an image on the retina
 Age 2-3 months





Anything that disrupts the stimulation of the visual
cortex will likely result in visual impairment.
If left untreated, amblyopia can lead to irreversible
blindness.
Duration of amblyopia and the age at onset
determine how rapidly normal acuity can be
achieved with proper treatment.
Amblyopia from a unilateral congenital cataract
requires surgery within the first few months of life
and is less effectively treated after 1 to 2 years.
Strabismic amblyopia may be treated effectively up
to 4 years of age.
Natural History of Visual System


Infants are often born with benign eso-or exotropia
that resolves within 2 – 3 months of age.
Pseudostrabismus or pseudoesotropia
 Appearance of crossed eyes due to a flat nasal bridge,
prominent epicanthal folds, or a narrow interpupillary
distance.
 Should resolve as the child’s nose narrows and becomes
more prominent, thus pushing the epicanthal folds away
from the eyes.

Refractive errors (decreased visual acuity) is more
controversial.
 7 – 9% of children grades 1-3 have prescription glasses.
Figure rises to 30% by late teens.
 Disagreement about whether if left undiscovered refractive
error affects academic performance adversely.
Primary Prevention

Early prenatal care
 Screen and immunize women before pregnancy for rubella.
 Counsel m0thers regarding potential teratogens
○ Drugs during pregnancy
○ LSD exposure can result in coloboma (defect in the uveal
tract that can affect several structures including the iris and
optic nerve head.
 Screening/counseling/Treatment for avoidance of potential
maternal infections
○ Rubella – newborn cataracts, pigmentary, microphtalmia
○ CMV (cytelomegalovirus) – chorioretinitis, strabismus, optic
atrophy, microphthalmia, cataracts. Avoidance of acute viral
illness. Mimics Epstein bar virus
○ Toxoplasmosis – chorioretinitis. Avoid cat litter boxes.
○ Chlamydia/Gonorrhea – ophthalmia neonatorum, gonorrheal
conjunctivitis resulting in corneal ulceration with scarring or
perforation of globe. Screen and treat.
Primary Prevention Cont…

Birthing/Immediate post-partum
 Avoidance of forceps delivery
○ May result in lid swelling, corneal
opacification and laceration,
hemorrhage, and rupture of the globe.
 Prophylactic Treatment at time of delivery
for gonorrhea prophylaxis (does not cover
for chlamydia)
○ 1% silver nitrate, 0.5% erythromycin
ointment, or 1% tetracycline ointment to
neonate’s eyes immediate postpartum
Secondary Prevention

Clinical screening
 Complete and accurate history at every well child exam with
appropriate follow-up.
○ Parental concerns
○ Does the child blink at bright light?
○ Does the infant regard mother’s face?
 Eye examination with appropriate screening guidelines per AAP.
See next slide.

School based Screening
 School entry based and additional 2 – 3 times during elementary
and middle school vision-screening programs
 School nurse referrals
○ Failing screening test, headaches, blurry vision, difficulty in
reading, poor school performance.
○ Most do not have a visual problem – should be screened by
primary care first for complete medical history, neurological
evaluation, and vision screening.
Secondary Screening
Recommendations

AAP Recommendations
 Advises testing every 1- 2 years through adolescence
○ American Academy of Ophthalmology and American
Optometric Association agree with AAP.
 Ages 3 and older
○ Distance visual acuity
 Snellen letters/numbers, Tumbling E, HOTV, Picture tests (Allen
figures)
○ Ocular alignment
 Unilateral cover test at 10 ft, Random dot, E stereogram at 40 cm

USPSTF Recommendations
 Advises screening of ocular alignment between ages 3- 4.
 Does not sanction routine screening for school age
children.
Clinical Examination




Inspection of ocular structures for symmetry and
function
Pupillary response
Appearance of conjunctiva, cornea, iris, and sclera.
Red reflex with opthalmoscope held 12 inches away
 Asymmetry of pupils, dark spots within the red reflex or
lack of a red reflex should prompt referral.
 Presence of white reflex (leukokoria), can indicate
retinoblastoma – Ocular emergency.


Age appropriate vision screening every well child
exam
Formal vision screening should begin at age 3 years
using the most sophisticated test with which the child
is able to cooperate.
Secondary - Screening Tests

Corneal Light Reflex (Hirschberg Test)
 Child looks into penlight. Check light reflected off the
corneas is positioned in the center of the pupil and is
symmetrical in location.
 Normal results with pseudostrabismus; Asymmetry may
indicate ocular malalignment which requires follow-up with
ophthalmology.

Cover/Uncover Test
 Child focuses on an object at a distance with both eyes
open. Examiner occludes one eye while looking for
movement in the uncovered eye.

Alternate Cover Test
 Alternating the cover from one eye to the other without
allowing adjustment to binocular vision. If any eye
movement is noted, considered an abnormal test result
that requires referral to an ophthalmologist.
Secondary - Screening Tests

Eye Charts for Visual Acuity
 Allen Cards
○ Simple pictures held at 10 feet.
○ 2-3 year old children.
○ Important to verify children are able to identify
with the figures before conducting the actual
vision test
 Tumbling E Chart
○ Several capital letter E’s oriented in different
directions. Child must indicate direction of
arms with use of their fingers
○ 4 – 5 year old children
○ 10 – 20 foot distance
Secondary – Screening Tests
 HOTV Chart
○ Combination of different sized letters H,O,T,V.
Provider points to a letter, then child points to a
matching letter on hand held card.
○ 3 to 5 year old children
○ 10 – 20 foot distance
 Snellen Acuity Chart
○ Letters and numbers. Best used with school aged
children
 Optec Vision Testing System
○ Evaluates near and far visual acuity, phorias, color
and contrast vision.
○ Child looks into a viewer, examiner selects a test.
Less peripheral distraction than wall chart.
○ More costly for system.
Secondary – Screening Tests

Normal Visual Acuity Results
 20/40 – normal for 3 year-olds
 20/30 – normal for 4 year-olds
 20/20 – normal for 5 – 6 year-olds
 A difference of more than one line between
the two eyes is abnormal and may indicate
amblyopia or a refractive error.
○ Requires a referral to an ophthalmologist
Secondary - Screening Tests

Stereoscopic Testing
 Detects amblyopia and strabismus.
 Binocular vision develops by four months of age.
 AAP recommends the unilateral cover test or
random dot E stereogram to test for ocular
alignment.
 Random dot E stereogram test – page of dots. Child
places on a pair of three-dimensional glasses that
enable the child to see geometric figures such as a
letter E.
 Children with amblyopia will not see these shapes.
 Test is easy to administer and only takes a few
minutes.
Secondary – Screening Tests

Photorefraction
 Standard refraction testing involves determining the





proper eyeglass lens to correct vision.
Photorefraction is a photographic technique
designed to detect ocular anomalies by using a light
reflex that is generated by placing a flash source
slightly above or below a camera lens.
Identifies refractive error, ocular alighment, and
clarity of lens
Compact and easy to use
Does not require a response from the child
Limitations include expense and delay in obtaining
results. (Film usually sent out for processing and
analysis).
Tertiary Prevention
Assist with referrals
 Treatment monitoring
 For vision impaired – assist and
encourage development of socialization
skills.
 Assist with IEP planning in the school
program
 Encourage and support parents.

Common Errors
Not providing screening
 Lack of follow-up
 Performing tests improperly
 Referrals for pseudostrabismus

Emerging Trends


Screening
 New computer based programs for mass testing and more
accurate testing.
Assistance for Visually Impaired Child
 Technological advances
○ Camera used to project enlarged newsprint for child to read
 Web sites for visually impaired

Validation of Current Screening tests and their benefits
 Studies needed to document sensitivity and specificity of
commonly used screening tests.
○ Accuracy can then be compared with new automated
screening devices.
 Studies to validate cost-effectiveness of universal,
periodic visual acuity screening in schools.
 More exploration of the relationship of asymptomatic
refractive errors to school performance and outcomes.
Color Vision Testing
Ishihara color plates
 Males 8% deficient
 Females 0.5% deficient
 Test in 3rd to 7th grade

Vision Screening

Birth
 Observation and inspection
 Red reflex testing
Vision Screening

4-6 months of age
 Observation and inspection
 Corneal light reflex testing
 Bruchner red reflex testing
Vision Screening

Toddler
 Observation and inspection
 Corneal light reflex testing
 Bruchner red reflex testing
 Cover test for alignment
 Cover test for amblyopia or organic vision loss
Vision Screening

Pre-school
 Observation and inspection
 Corneal light reflex testing
 Bruchner red reflex testing
 Cover test for alignment
 Cover test for amblyopia or organic vision loss
 Distance visual acuity
Vision Screening

School-age
 Observation and inspection
 Corneal light reflex testing
 Bruchner red reflex testing
 Cover test for alignment
 Cover test for amblyopia or organic vision loss
 Distance visual acuity
 Other optional tests
Vision Screening Pearls

Infants and Toddlers
 Toy over light allows easier and more
accurate corneal light reflex testing
 Bruchner red reflex testing underutilized but
valuable
 “Objects to cover” may equal Amblyopia
Vision Screening Pearls

Pre-school and School-age
 Make testing fun
 Beware of the ‘professional peeker’
 Testing at 10 feet may be better