Squint Flashcards
What are the signs of retinoblastoma?
Strabismus - cross eye
Leukocoria - white pupil
Absent red reflex
What type of gene is the retinoblastoma gene?
Tumour suppressor
What is esotropia?
Convergent squint - towards nose
What may cause esotropia?
Hypermetropia
What is exotropia?
Divergent squint - away from nose
How are squints identified?
Corneal reflection - light should reflect back from the centre of each pupil
Cover test - if pupil moves to take over fixation there is a squint
How are squints treated?
Optical - glasses to correct refractive errors
Orthoptic - patch good eye
Operation - resection and recession of rectus muscles (above and below eyeball)
What are the signs of CNIII palsy?
Oculomotor - rectus muscles
Ptosis
Proptosis
Fixed pupil dilation
Down and out position
What are the signs of CNIV palsy?
Trochlear - superior oblique
Diplopia
Tilted head
Eyes look upwards in adduction (‘look towards nose’)
Cannot look down and in
What are the signs of CNVI palsy?
Abducens - lateral rectus
Diplopia in horizontal plane
Medially deviated eye and cannot move laterally from the midline
What movements is the lateral rectus muscle responsible for?
Lateral rectus - look away from your nose
What movements is the medial rectus muscle responsible for?
Medial rectus - look towards your nose (adduction)
What movements is the superior rectus muscle responsible for?
Moves gaze upwards
Rotates top of the eyes towards the nose
What movements is the inferior rectus muscle responsible for?
Moves gaze down
Rotates bottom of the eyes towards nose
What movements is the superior oblique muscle responsible for?
Rotates top of the eye towards the nose
Moves gaze down
