Estrabismo

The nurse is caring for a child suspected of having strabismus and is preforming a corneal light reflex test.

Which finding does the nurse identify as a sign of this condition?

• A.Symmetrical pin-point light on each pupil

• B.Red reflex in both eyes

• C.Asymmetrical pin-point lights on the pupils

• D.Sun setting sign

Answer explanation

Choice C is correct. Asymmetrical pin-point lights on the pupils are a sign of strabismus. If the nurse suspects that the child has strabismus and conducts a corneal light reflex test, this may confirm her suspicions. This child should have a full eye exam performed to confirm the diagnosis and receive proper treatment.

Choice A is incorrect. A symmetrical pin-point light on each pupil is the normal finding in a corneal light reflex test. This is not a sign of strabismus.

Choice B is incorrect. The red reflex is a normal sign in healthy eyes. It occurs when light passes through the pupil and is reflected back off the retina to a viewing aperture, creating a reddish-orange glow.

Choice D is incorrect. Sun setting sign is an indication of increased intracranial pressure that presents when the eyes appear driven downward. The sclera is seen between the upper eyelid and the iris, while part of the lower pupil may be covered by the lower eyelid. The nurse does not assess for this sign with a corneal light reflex and it is not a sign of strabismus.

A nurse is caring for a 2-year-old with a new diagnosis of strabismus.  Which intervention should the nurse anticipate?

•   1. Correction with laser surgery

•   2. Eye drops in the affected eye

•   3. Measurement of intraocular pressure

•  4. Patching of the unaffected eye

Answer explanation

Strabismus (ie, ocular misalignment) occurs when both eyes cannot simultaneously focus on the same image.  It is characterized by deviation of the affected eye, in any direction, away from a point of fixation.  Strabismus can be congenital (eg, Down syndrome) or acquired (eg, stroke, Guillain-Barré syndrome).  Intermittent strabismus can be expected in infants age <4 months due to immature ocular muscles.  However, strabismus beyond early infancy must be treated to prevent decreased visual acuity of the deviated eye (ie, amblyopia).

Treatment involves correcting significant refractive errors (ie, nearsightedness, farsightedness) and promoting use of the affected eye.  For example, by patching the normal eye, the affected eye can be strengthened (Option 4).

(Option 1)  Laser surgery to correct weak eye muscles is indicated if noninvasive methods fail.

(Option 2)  Eye drops (eg, atropine) to blur vision of the normal eye are indicated to strengthen and promote use of the affected eye.  Placing eye drops to blur the vision of the affected eye could worsen amblyopia.

(Option 3)  Monitoring of intraocular pressure (IOP) would be necessary in a client with glaucoma.  Strabismus is not associated with abnormal IOP.

The clinic nurse is planning to assess the visual acuity of a 6-year-old.  Which method is the best way to assess visual acuity in this child?

•   1. Have the child identify different objects using Allen figure testing cards

•   2. Have the child point in the direction each letter is facing on a tumbling E chart

•   3. Have the child read letters on a Snellen chart while standing 10 ft (3 m) away

•   4. Have the child view a set of Ishihara colored cards one at a time

Answer explanation

Visual acuity measurement for children age 6 years and older is best performed by using the Snellen letter chart (Option 3).  The child is positioned 10 ft (3 m) from the chart and is asked to read the letters on each row from left to right.  Although standard testing for visual acuity is at a distance of 20 ft (6 m), the American Academy of Pediatrics recommends testing at 10 ft (3 m) as it is easier to maintain the child's attention for a more accurate result.

The nurse ensures the following when using the Snellen letter chart:

If the child wears glasses, they should be worn during testing.
One eye at a time is covered while the child reads the chart out loud; however, both eyes should remain open during testing.
Four to six letters must be identified in each row before proceeding to the next.
(Options 1 and 2)  Using Allen figure testing cards and a tumbling E chart are recommended for preschoolers ages 3 to 5.  The Snellen letter chart is more appropriate for the cognitive ability of a 6-year-old.

(Option 4)  Viewing a set of Ishihara cards one at a time is a test of color vision deficits, not visual acuity.

The nurse is performing visual acuity screenings on a group of students.  Which of the following student comments does the nurse recognize as indicating possible myopia?  Select all that apply.

•  1. "I can see my teacher better if I sit in the back of the classroom."
  

• 2. "I have to hold my book close to my face so that the words are clear."
  

•  3. "If I squint or close one eye, I can read the road signs when we travel."
  

•  4. "My parents always tell me that I am sitting too close to the television."
  

•  5. "Sometimes, I have to ask my parents if I've chosen socks that match."

Answer explanation

Myopia, or nearsightedness, is reduced visual acuity when viewing objects at a distance.  Myopia occurs when the eye structure causes images to focus before they arrive at the retina.  Near vision is usually intact, and many clients with myopia report needing to hold objects near their face or sit near objects to see clearly (Options 2 and 4).

Myopia in pediatric clients may first be discovered by the school nurse during routine visual acuity testing.  Children often report headaches, dizziness, and the need to squint the eyes to see clearly (Option 3).  School performance may be affected because of impaired ability to see class presentations.

(Option 1)  Reduced visual acuity when viewing objects up close with intact distance vision is associated with hyperopia.  Clients with hyperopia may report having to hold materials far away to read or sit at a distance to have clear vision.

(Option 5)  Impaired ability to perceive and differentiate colors (eg, red and green, blue and yellow) is associated with color vision deficiency, a congenital impairment of cone function in the retina.  Children with color deficiency may have difficulty selecting matching clothing or appropriate colors for school assignments.

. The day care nurse is observing a 2-year-old child
 and suspects that the child may have strabismus.
 Which observation made by the nurse indicates the
 presence of this condition?

• 1. The child has difficulty hearing.
  

• 2. The child consistently tilts the head to see.
  

• 3. The child does not respond when spoken to.

• 4. The child consistently turns the head to hear

Answer explanation

 Rationale: Strabismus is a condition in which the eyes are
 not aligned because of lack of coordination of the extraocular
 muscles. The nurse may suspect strabismus in a child when
 the child complains of frequent headaches, squints, or tilts the
 head to see. Other manifestations include crossed eyes, clos
ing one eye to see, diplopia, photophobia, loss of binocular
 vision, or impairment of depth perception. Options 1, 3, and
 4 are not indicative of this condition.
 Test-Taking Strategy: Eliminate options 1 and 4 first because
 they are comparable or alike and relate to hearing. To select
 from the remaining options, recall that this is a condition in
 which the eyes are not aligned because of lack of coordination
 of the extraocular muscles.