A 4-year-old child presents for a well-child visit. The nurse suspects strabismus. The most indicative finding is a lack of proper eye alignment when focusing on an object. This is assessed through specific techniques.
Key Assessment Techniques
- Corneal Light Reflex (Hirschberg Test): Shine a light at the child's eyes from about 12 inches away. Observe the light reflection on the corneas. In normal alignment, the reflection is symmetric. In strabismus, the reflection is asymmetric (e.g., centered on one pupil but off-center on the other).
- Cover-Uncover Test: Have the child focus on a distant object. Cover one eye and observe the uncovered eye for movement. A shift in fixation to pick up the target indicates that eye was deviated. Uncover the eye and observe it for a refixation movement, which confirms a tropia (manifest deviation).
- Observation of Head Posture: Note any abnormal head tilt or turn the child uses to compensate for misalignment and achieve single binocular vision.
Differential Findings to Rule Out
- Eye Pain and Tearing: More indicative of corneal abrasion, foreign body, or conjunctivitis. Assess with fluorescein stain or eversion of the eyelid.
- Difficulty with Distance Vision: Suggests myopia. Assess with a Snellen chart or picture chart for pre-literate children.
- Signs of Increased Intraocular Pressure: Such as a fixed, dilated pupil, cloudy cornea, or excessive blinking/buphthalmos. This points to congenital glaucoma and requires emergent ophthalmology referral.
Nursing Action
If asymmetric corneal light reflex or a refixation movement is observed during the cover test, document the findings as "positive for ocular misalignment" and facilitate a referral to a pediatric ophthalmologist. Early detection and treatment are critical to prevent amblyopia (lazy eye) and permanent vision loss.