Transcript squint - WordPress.com

STRABISMUS (SQUINT)
Amaka Azie
GPST2
• It is a condition in which the eyes are misaligned
• Can lead to amblyopia in childhood or diplopia in adult hood
• Amblyopia (lazy eye),happens when because of lack of use of the eye
in childhood, vision becomes poor
• Latent squint– Also known as heteroPHORIA is a very slight squint
not present all the time and can be seen in only certain circumstances
• Manifest squint- HeteroTROPIA is present all the time
ANATOMY: MUSCLES OF EYE MOVEMENT
• All movement of the eyes are
enabled by the third nerve
• Except superior oblique=> fourth
nerve and lateral rectus =>sixth
nerve
• The third, fourth and sixth nuclei
and the higher brain centres are
involved
• When the eyes are looking
straight ahead =primary position
TYPES OF SQUINT
Non-paralytic squint (concomitant squint):
• Normal eye movements but only one eye is directed to the target.
• Unrelated to the direction of gaze
• More common in children
Paralytic squint (Incomitant squint):
• Weakness or paralysis of one or more muscles of eye movement
• Dependent on direction of gaze and usually worse where eye is
moved towards the field of action of affected muscle or nerve
IMORTANT TERMS
• ESOtropia=> Inwards
• EXOtropia=>Outwards
• Hypotropia=>Downwards
• Hypertropia=>Upwards
IMORTANT POINTS TO NOTE
• Squint could be classified as congenital (Onset before 6 months) or
acquired
• Squint or some form of ocular misalignment are common in
newborns.
• Should be intermittent, reducing by 2 months of age and disappear
by 4 months of age
• Esotropias are more common than exotropias. Hypo and hypertropias
are not common
Non-Paralytic squint
SUSPECT IF:
• May be noticed by parents
• May be detected in pre-school screening
• Children may tilt their head or chin to compensate for amblyopia
SCREENING :
Hirschberg’s test: Pen torch some distance in front of eyes. Reflection
should lie centrally bilaterally on the cornea normally.
It can also be used to estimate degree of deviation
CAUSES:
• Family history
• Neonatal jaundice
• Prematurity
• Fetal alcohol syndrome
• Encephalitis, mengitis
• Down syndrome/Turners syndrome
• Refractive error
• Cataracts
• Retinoblastoma
Diagnosis=Cover/uncover test
Alternate cover test=> Latent squint
Cover /uncover test
COVER TEST vs ALTERNATE COVER TEST
• Cover one eye for a few second
while uncovered eye focuses on
object. Remove and place on
other eye. If initially covered eye
moves outwards=> Esophoria.
• Alternate cover test detects
latent squint by breaking
bifoveal stimulation. Done by
switiching occlude rapidly
between both eyes
MANAGEMENT
Referral to eye clinic
• Neonate with constant squint, worsening squint from 2 months or
squint still present after 4 months
• Any older child with a suspected squint
• Management include spectacles, patches, cycloplegic drops and
surgery
• Prognosis is good if detected early
Thanks for listening.