Strabismus (squint)

Eyes are not aligned properly
Up until 3 months of age can be normal
Rule out pseudostrabismus
- May occur when babies have flattened nasal bridge and asymmetrical epicanthic folds
- assess ocular alignment – torch for corneal light reflections – should be symmetrical
- Also check red reflex in symmetrical (from a few feet away)
Red flags
- Recent trauma
- Symptoms of raised intracranial pressure (e.g. morning headaches, vomiting)
- New strabismus in a school-age child
History of presenting complaint
- Onset (e.g. dependent on the direction of gaze or time of day)
- Reduced visual acuity
- Diplopia
- Asthenopia (i.e. eye strain, fatigue or pain), particularly in the afternoon or at the end of the day
- Decreased academic and/or work performance
- Decreased socialisation
- Behavioural problems
- Maladjustment at home or school
- Walking difficulties (i.e. bumping into objects, tripping over)
Cover test (a.k.a. single-cover test)

The cover test is used to determine if a heterotropia (i.e. manifest strabismus) is present.
A patient is asked to fixate on a target (e.g. light switch).
One of the patient’s eyes is occluded and the non-occluded eye is observed for a shift in fixation:
1. If there is no shift in fixation in the contralateral eye, while covering either eye, the patient is orthotropic (i.e. normal alignment).
2. If there is a shift in fixation in the contralateral eye, while covering the other eye, the patient has a heterotropia.
the cover test is then repeated on the other eye.
The direction of the shift in fixation determines the type of tropia; the table below describes the appropriate interpretation.
If doesn’t correct alignment – strabismus surgery should be considered prior to 12 months – window of neurological development