Squint Flashcards
What is a Squint?
A misalignment of the eyes - strabismus.
What are the 4 descriptions of a Squint?
- Esotropia - medial positioning of squint (commonest).
- Exotropia - lateral positioning of squint.
- Hypertropia - upward positioning of squint.
- Hypotropia - downward positioning of squint.
What is the danger of a squint in kids?
Any cause of reduced visual stimulation in one eye e.g. squint, unequal refractive error, congenital cataract can cause amblyopia (reduced functioning of the lazy eye).
Aetiology of Squint (5).
- Idiopathic - otherwise healthy (usually).
- Hydrocephalus.
- Cerebral Palsy.
- Space Occupying Lesions e.g. Retinoblastoma.
- Trauma.
What are concomitant (idiopathic) squints due to?
Differences in the control of extra ocular muscles.
Vision with a Squint.
When the eyes are not aligned, the images do not match so the person will experience diplopia (double vision).
Investigations of Squint (3).
- Clinical Examination.
- Hirschberg’s Test.
- Cover Test.
What is Hirschberg’s Test? (3)
- Shine a pen torch at the patient 1m away.
- When they look at it, observe the reflection of the light source.
- Reflection = Central and symmetrical. Deviation = Squint.
What is Cover Test (2)?
- Patient covers one eye and focuses on an object in front of them.
- Move the cover across to the opposite eye and watch the movement of the previously covered eye.
What is the important age mark before a squint becomes permanent?
8 Years - visual fields are still developing.
Management of Squint (2).
- Occlusive patch covers dominant eye and force the weaker eye to develop.
- Atropine Drops in dominant eye blurs vision.