Strabismus

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Strabismus Nursing Care Planning and Management
Strabismus: A Study Guide for Nurses

John is really careful about his daughter. He clears the living room whenever his 4-year old decides to take a trip there. He helps her see pictures clearly on her picture book through leaning nearer the book. He does this because his daughter has strabismus. When the day of the surgery arrived, John prayed that his daughter will emerge safe and have a normal life ahead.

Definition


Strabismus is the inward deviation of the eyes noted before the patient reaches age six (6) months.

  • Strabismus is associated with maldevelopment of stereopsis, motion processing, and eye movements.
  • Strabismus is a visual problem in which the eyes are not aligned properly and point in different directions.
  • To date, its exact cause has yet to be identified, and an effective treatment strategy is yet to be formulated.
Types of Strabismus | RelayHealth

Pathophysiology


The exact cause of strabismus remains unknown.

  • Worth strongly believed that esotropia is an inborn and irreversible defect of fusion.
  • As such, it is a primary dysfunction in the normal development of binocular sensitivity.
  • This was countered by Chavasse who asserted that the neural components necessary for normal binocular vision are present in strabismic individuals at birth, but the development of fusion is eventually impeded by abnormalities of optical input (eg, monocular cataracts) or muscular output (eg, cranial nerve palsies).
  • A few authors have implicated practically everything from and between the extraocular muscles to the visual cortex in the causation of strabismus.
  • Although understanding the mechanisms behind strabismus has come a long way, there is still a lot of ground to cover to unearth and clearly understand such an elusive condition.

Statistics and Incidences


The incidence of strabismus in the United States and all over the world are as follows:

  • Strabismus is one of the most prevalent ocular problems among children, affecting 5 in every 100 US citizens, or some 12 million people in a population of 245 million.
  • A population-based study from 1965 to 1994 reports the birth prevalence of strabismus to be 25 per 10,000 or 1 in 403 live births.
  • In an attempt to determine whether esotropia is present at birth or develops later in infancy, Nixon et al observed 1,219 alert infants in a normal newborn nursery at a city hospital and noted that only 40 babies (3.2%) had esotropia (intermittent esotropia in 17 patients, with 14 patients varying between esotropia and exotropia, and 9 patients with variable esotropia).
  • Greenberg et al reported an annual age- and gender-adjusted childhood strabismus incidence of 111 per 100,000 patients younger than 19 years.
  • By definition, strabismus is seen in infants before age 6 months.

Causes


The exact cause of strabismus has yet to be identified distinctively.

  • Genetics. Tychsen and Lisberger reported in 1986 that the strabismic patient who had the most severe pursuit/motion processing asymmetry had two (2) siblings with strabismus.
  • Loci susceptibility. On the other hand, there is a suggested relationship of nonsyndromic strabismus to the susceptibility loci on regions 3p26.3-26.2 and 6q24.2-25.1 and may share alleles that underlie Duane retraction syndrome.
Duane Syndrome type I in left eye of a 10-year-old girl

Clinical Manifestations


According to Tychsen, strabismus manifest with a constellation of ocular motor signs, as follows:

  • Esotropia. Esotropia is in-turning of one or both eyes; it may be intermittent or constant and may occur with near fixation, distance fixation, or both.
  • Pursuit asymmetry. Horizontal smooth pursuit develops for targets moving in a temporal to nasal direction before pursuit movements in a nasal to temporal direction develop; this developmental lag in nasally directed smooth pursuit is called smooth pursuit asymmetry and is only seen under monocular conditions with one eye covered.
  • Latent fixation nystagmus.  Latent nystagmus is a horizontal binocular oscillation that is evoked by unequal visual input to the 2 eyes; it develops primarily in humans with congenital esotropia.
  • Amblyopia. Amblyopia is relatively common in patients with strabismus; Weakley et al stated that amblyopia should be suspected strongly in patients with esotropia and asymmetric inferior oblique activity, specifically in the eye with more inferior oblique overaction.

Assessment and Diagnostic Findings


Procedures to diagnose strabismus include the following:

  • Alternate prism cover test. Perform the alternate prism cover test to accurately measure the angle of strabismus; this procedure gauges the full magnitude of any combined esotropia and esophoria.

Medical Management


Smaller angles of deviation may be addressed with prism lenses with or without occlusion therapy, depending on the existence of amblyopia.

An eight-month-old infant undergoing surgery to correct strabismus | Image released by the United States Navy
  • Cycloplegia. A common cycloplegic combination is 2.5% phenylephrine and 1% cyclopentolate; it is necessary to occlude one eye at a time during retinoscopy to make sure that the examiner maintains accurate alignment with the visual axis.
  • Corrective lenses. Corrective lenses generally are prescribed with hyperopia greater than +2.50 diopter (D) and/or when anisometropia exceeds 1.50 D; in addition, any cylinder greater than or equal to +0.50 D should be given spectacles; on the other hand, myopia above -4.00 D warrants corrective lenses.
  • Occlusion therapy. The rule of thumb observed is 1-2 weeks of high percentage (eg, 90% of waking hours) occlusion of the non- amblyopic eye per year of life, especially if a strong fixation preference for one eye is detected; the infant is reexamined after a few weeks to determine response to therapy and to ensure that occlusion-induced amblyopia has not developed in the occluded dominant eye.
  • BOTOX. Botulinum toxin (BOTOX®) injection into the medial rectus has been explored as an alternative therapy to surgery; several studies have investigated the merits of such a procedure with contrasting results.
Isolating the inferior rectus muscle
Disinserting the medial rectus muscle

Pharmacologic Management

Very few medications are used in the treatment of strabismus; combination antibiotic-steroid ointments are prescribed for the first postoperative week. BOTOX® injection has been used as an alternative to initial or repeat surgical ocular alignment.

  • Combination antibiotic-steroid ointments. Used in the first postoperative week to control any inflammation and to prevent any infection resulting from surgery, particularly in the conjunctiva.
  • Neurotoxins. Botulinum toxin type A (BOTOX®) is most commonly used; inhibits transmission of nerve impulses in neuromuscular tissue.

Nursing Management


Nursing care for a child with strabismus include:

Nursing Assessment

Assessment of a child with strabismus include the following:

  • History. Certain risk factors have been associated with strabismus; significant among these are prematurity, family history or secondary ocular history, perinatal or gestational complications, systemic disorders, use of supplemental oxygen as a neonate, use of systemic medications, and male sex.
  • Physical exam. Strabismus may be associated with a spectrum of clinical presentations, including amblyopia, impaired binocularity, central scotomas, and incomitance.

Nursing Diagnoses

Based on the assessment data, the major nursing diagnoses are:

  • Risk for injury related to impaired sensory function.
  • Disturbed sensory perception related to structural damage.
  • Knowledge deficit related to impaired vision.
  • Social isolation related to the limited ability to participate in diversion activities and social activities secondary to impaired vision.

Nursing Care Planning and Goals

The major nursing care planning goals for patients with strabismus are:

  • Patient will be free from injury.
  • Patient will have a restored, functioning sensory perception.
  • Patient and/or folks will have an understanding of the condition, the treatment, and surgery.
  • Patient will be able to interact socially with others.

Nursing Interventions

Nursing interventions for a child with strabismus include the following:

  • Prevent injury. Thoroughly conform patient to surroundings; put call light within reach and teach how to call for assistance; respond to call light immediately; place an injury-prone patient in a room that is near the nurses’ station; educate patient about safety ambulation at home, including the use of safety measures such as handrails in bathroom; for patients with visual impairment, educate him or caregiver to label with bright colors such as yellow or red significant places in environment that must be easily located (e.g., stair edges, stove controls, light switches).
  • Patch therapy and vision therapy. In patch therapy, the child’s stronger eye is covered with a patch, forcing the weaker eye to function at a higher level; vision therapy consists of exercises performed in the eye doctor’s office under supervision to change the way the eyes process visual information; it is not concerned with strengthening the eye muscles.
  • Enforce the caregiver’s knowledge. Observe and note existing misconceptions regarding material to be taught; acknowledge racial/ethnic differences at the onset of care; consider the patient’s/caregiver’s learning style, especially if the patient/caregiver has learned and retained new information in the past; include the patient/caregiver in creating the teaching plan, beginning with establishing objectives and goals for learning at the beginning of the session; provide clear, thorough, and understandable explanations and demonstrations.

Evaluation

Goals are met as evidenced by:

  • Patient will be free from injury.
  • Patient will have a restored, functioning sensory perception.
  • Patient and/or folks will have an understanding of the condition, the treatment, and surgery.
  • Patient will be able to interact socially with others.

Documentation Guidelines

  • Baseline and subsequent assessment findings to include signs and symptoms.
  • Individual cultural or religious restrictions and personal preferences.
  • Plan of care and persons involved.
  • Teaching plan.
  • Client’s responses to teachings, interventions, and actions performed.
  • Attainment or progress toward the desired outcome.
  • Long-term needs, and who is responsible for actions to be taken.

Practice Quiz: Strabismus


Here’s a 5-item quiz for Strabismus study guide:

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Practice Quiz: Strabismus

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1. Nurse Bean is doing an assessment of a child with strabismus. Which of the following is consistent with the said condition? 

A. Presbyopia
B. Myopia
C. Diplopia
D. Milky-white lens

1. Answer: C. Diplopia

  • Option C: Diplopia, or crossed eye, is a major symptom of strabismus.
  • Option A: Presbyopia is an error of refraction that occurs among the elderly.
  • Option B: Myopia is an error of refraction.
  • Option D: A milky-white lens is a sign of a cataract.

2. A mother brings her 2-year-old to the pediatrician’s office. Which of the following symptoms suggests to the nurse that the child has strabismus?

A. The child rubs his eyes frequently.
B. The child closes one eye to see a poster on the wall.
C. The child places his head close to the table when drawing.
D. The child is unable to see objects in the periphery of his visual field.

2. Answer: C. The child places his head close to the table when drawing.

  • Option C: Double vision or diplopia occurs in children with strabismus, so the child places his head close to the table to see clearly.
  • Options A, B, and D: These options are not present in a child with strabismus.

3. A daycare nurse is observing a 2-year old child and suspects that the child may have strabismus. Which observation made by the nurse might indicate this condition?

A. The child does not respond when spoken to.
B. The child has difficulty hearing.
C. The child consistently tills the head to see.
D. The child consistently turns the head to see.

3. Answer: C. The child consistently tills the head to see.

  • Option C: 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.
  • Options A, B, and D are not indicative of this condition.

4. At a well-child exam, a 3-year-old boy is diagnosed with strabismus. Which of the following clinical manifestations does the nurse interpret as indicative of this disorder? Select all that apply:

A. Closing one eye to see
B. Positioning self-close to the TV
C. Squinting
D. Difficulty doing close work
E. Excessive eye rubbing
F.  Tilting head to one side to see

4. Answers:  A, C, and F.

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  • Options A, C, and F:  In strabismus, the eyes are misaligned, so the child makes efforts to improve focus. The child tilts the head to one side in an effort to improve visual alignment. Other clinical manifestations include squinting, appearing cross-eyed, or closing one eye to see.
  • Options B, D, and E: Excessive eye rubbing, difficulty doing close work, and sitting close to the television are all manifestations of myopia.

5. Which of the following statement regarding the use of Botulinum toxin Type A (Botox or Botox cosmetic) is not true?

A. Botox cosmetics permanently eliminates glabellar lines.
B. Botox is approved for use in the ocular conditions strabismus and blepharospasm.
C. The botulinum toxin is a potent poison produced by the bacteria Clostridium botulinum.
D. Botulinum toxin Type A is a neurotoxin that blocks the release of acetylcholine and blocks transmission at the neuromuscular junctions and cholinergic synapses.

5. Answer: A. Botox cosmetics permanently eliminates glabellar lines. 

  • Option A: Botox cosmetics blocks the transmission at the neuromuscular junction and cholinergic synapses. neuronal function is restored after several months, once new terminals develop. Thus the effect of Botox cosmetic on the elimination of glabellar lines is only temporary.
  • Options B, C, and D are all correct about Botox.

See Also


Related topics to this study guide:

Further Reading


Recommended resources and books for pediatric nursing:
  1. PedsNotes: Nurse's Clinical Pocket Guide (Nurse's Clinical Pocket Guides)
  2. Pediatric Nursing Made Incredibly Easy
  3. Wong's Essentials of Pediatric Nursing
  4. Pediatric Nursing: The Critical Components of Nursing Care

Strabismus Nursing Care Planning and Management

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