Strabismus
Causes include:
Comitant strabismus
- decompensation of pre-existing latent strabismus
- full ocular movements
- esotropia (convergent) > exotropia (divergent) strabismus
3rd Nerve palsy
- ptosis >2mm
- exotropia (divergent) and hypotropia (down) typically
- limitation of elevation / depression / adduction
- pupil dilated and poorly reactive or pupil sparing
4th Nerve palsy
- limitation of depression of eye in adduction
- ipsilateral hypertropia (elevation of eye)
- worse in contralateral gaze and ipsilateral head tilt
- older child will complain of tilt of second image
6th Nerve palsy
- limitation of abduction (unable to bury the limbus in the outer canthus)
- esotropia (convergent strabismus) greater when fixing on distant targets
- subjective horizontal diplopia especially when looking at distant targets
Supranuclear gaze palsy
- gaze palsy (e.g. vertical gaze palsy and convergence retraction nystagmus associated with pinealoma – Parinaud’s syndrome).
Orbital infiltration (e.g. leukemia/lymphoma/metastases/rhabdomyosarcoma)
- restricted eye movements
- proptosis
- +/- pain
Intraocular cause (e.g. Retinoblastoma / Intraocular lymphoma / leukaemia)
- Poor red reflex
- Poor vision (poor take up of fixation with the deviating eye)
Clinical Tip :
Cover test While presenting a near / distant target, cover one eye at a time and then uncover.
Movement of the other eye to take up fixation will alert you to manifest strabismus (unless poor vision / limitation of eye movement)
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