SENSORY ALTERATIONS

VISUAL IMPAIRMENT

Parameters for VisionAge Vision Assessment Parameters

Infant

Toddler

Pre-schooler

School Age

Adolescent

Ability to follow objectsCorneal ReflexAbility to turn to light stimuli

Cornea Light ReflexCover TestSmooth Ocular MovementsHand-eye coordination

Corneal Light ReflexCover TestSnellen’s E Chart (or modification)

Visual Acuity Testing every 1-2 years

Visual Acuity Testing every 1-2 yearsVISION

Occurs because light rays reflect from an object thru the cornea, aqueous humors, lenses & vitreous humors to the retina

RETINA is studded with:1. ROD2. CONESFOVEA – an area of closely packed cones on the retinas where the color is best perceived

STEREOPSIS Is depth perception, or the ability to locate an object

is space relative to other objectsSTEREO-FLY OR RANDOM DOT TEST

A simple test for dot perceptionACCOMODATION

Is the adjustment the eye makes when focusing on a close image

DISORDERS THAT INTEFERE WITH VISION

REFRACTIVE ERRORS The largest category of vision defects in children

LIGHT REFRACTION Refers to the manner in which light is bent as it

passes thru the lens

1. Hyperopia – vision is blurry at a close range2. Myopia – the light rays focus at the point in front of

the retinaLaser in Situ Keratomileusis (LASIK)- A laser surgery for correction of myopia

ASTIGMATISM – is congenital or acquired unevenness of the curvature of the corneaNYSTAGMUS – rapid irregular movement, either vertically or horizontallyAMBLYOPIA – is ‟lazy eye” or subnormal vision in one eye; the child may be using one eye for cision while ‟resting” the other eye

Assessment Preschool E chart

o A child with amblyopia has 20/50 vision (normal for preschool age) in one eye, & the other eye shows lessened vision (perhaps 20/100)

Therapeutic Management1. Good eye is covered by a patch2. Administration of LEVEDOPA3. ATROPINE

COLOR VISION DEFICIT (COLOR BLINDNESS)- The inability to perceive color correctly- Occurs because one of the sets of cones of the retina

that perceive red green or blue is absent.- (pls add ISHIHARA PLATE)

COLOBOMA – is the congenital incomplete closure of the facial cleft.

o Children with retina & optic nerve coloboma will have some vision impairment

Structural Problems of the EyePtosis – inability to raise the upper eyelid normally so the eyelid always remains slightly closed

- In addition, children may exhibito Dilated pupilo Inability to rotate the eye globe upward,

medially, or downwardo Weakness of accommodation

- MYASTHENIA GRAVIS must always be ruled out as a cause of bilateral ptosis

- Ptosis is corrected surgically- If the lid obstruct vision, early surgery is necessary to

prevent the development of amblyopia- When child is older, ptosis can be corrected, the

amblyopia cannot

Strabismus – unequally aligned eye (cross-eyes) caused by unbalanced muscle control

- Infant’s eye may cross occasionally until 6 weeks of age

- Strabismus after 6 months should be referred for diagnosis & treatment

- Strabismus demonstrated before 6 weeks need referral right away

DEVIATIONS1. Exotropia – eye turning out2. Esotropia – eye turning in3. Hypertropia – eye turning up If deviation is not obvious & occurs only when the

child is fatigued or ill, terms used are Exophoria, Esophoria & Hyperphoria

Infectious and Inflammatory Eye DisordersSTYE – infection of a ciliary gland (a modified sweat gland) that enters into the hair follicle at the lid margin; most commonly caused by Staphylococcus.

S/S:1. Pain and redness at a localized point on the one lid

margin2. Possible edema of the lid out of proportion to the

severity of the disease3. Preauricular lymph node swelling & tenderness

Treatment:1. Hot, moist compresses for 15-20 mins. QID2. Antibiotic ointment application ( after compresses)3. Incision and drainage (when the stye point develops

a head)4. Nose and throat cultures for staphylococcus5. Follow-up evaluation for repeated episodes6. Visual acuity assessment

CHALAZION – Low-grade granulation tissue tumor of the meibomian, or tarsal, gland on the eyelid; cause unknown but may be a result of a low grade infection produced by retained secretion in the gland.

S/S:1. Small, slow-growing, hard but painless nodule on the

lid2. Skin freely movable over it3. Absence of inflammation or edema

Treatment1. None; may resolve spontaneously, evacuating itself

onto the conjuctival surface of the lid2. Incision & drainage if no spontaneous remission

followed by antibiotic ointment application to prevent secondary gland infection

3. If ptosis is present in a child younger than 8 years of age, surgical removal is performed to prevent possible subsequent amblyopia