pupils Flashcards
what is the target for pupils?
letter/ spotlight if va worse than 6/18b in poorer eye
procedure
1) with room light on - check size, shape and location of both pupils // if unequal sizes measure with ruler in mm
2)dim lights and measure size again
3) direct - observe speed and extent of constriction
4) consensual
CHECK SEVERALK TIMES
4) swinging flash light checks for rapid
normal - both pupils constrict
raid - eye will dilate as light is shone on it
1) what Is normal pupil size
2-6mm
<2
miotic due to pathology, drugs (pilocarpine) or physiology
> 6
midriatic- due to drugs( tropicamid´, cyclopentolate) , glaucoma iris injury
RAPD
Marcus Gunn pupil.
palsy o Defect in the afferent pathway (indicated within name).
o Causes: asymmetric glaucoma, optic neuritis, MS, RD, CRAO/CRVO, AAION.
o Effect: pupil dilation in affected eye on ‘swinging light test’
ANISOCORIA
Seen in about 20% of normal patients and is generally the same in bright and dim light.
o Pathological anisocoria is due to an abnormality in the efferent or motor pupil pathway.
o Anisocoria that is greatest in bright light will generally show an abnormal direct and
consensual light reflex.
This indicates a problem in the motor leg of the light reflex pathway, such as 3rd nerve palsy, Adie’s or could be drug induced.
AMAUROTIC PUPIL = blind eye
light is shone in the affected eye, both pupils do not respond due to being blind in affected
eye.
o If light is shone in the unaffected eye, both pupils respond normally and equally.
o Pupillary diameter is equal in both eyes.
o Near reflex (accommodative) normal.
o Caused by a complete unilateral optic nerve lesion.
symptoms of aides pupil
Mild blurring of vision,especially near(fromparalysisoftheciliarymuscle,whichfocusesthe lens).
o Glare(fromthedilatedpupil).
signs of Adie pupil
Dilated pupil with very poor constriction to light but which constricts slowly when the patient is asked to look at a near target (‘light-near dissociation’).
o No ptosis, normal eye movements.
adies pupil
ossibly a viral infection of the orbital ciliary ganglion causing lack of parasympathetic supply
to the eye. the iris sphincter muscle (which causes pupil constriction) is paralysed, resulting in
a dilated pupil.
o Unilateral(lesscommonlybilateral).
o Occurs in otherwise well patients.
o Commoninyoungerwomen.
o Adie’s in younger people – then concerned but with elderly people it’s common due to
damage within pupil pathway caused by viruses and infections throughout life.
management of aides pupil
Ophthalmic referral to confirm diagnosis.
- Elderly patient = routine referral
- Young patient = urgent referral, in case of neurological origin.
o Reading glasses might be necessary (especially if young patient due to paralysis of iris sphincter); sunglasses should be worn outside.
- How do you know the difference between a RAPD and an amaurotic pupil?
No direct and consensual reflex in Amaurotic
- Anisocoria vs. Adie’s?
Adie’s is unresponsive to light
Anisocoria is responsive to light, just difference in pupil sizes
ARGYLL-ROBERTSON PUPIL (miotic pupils)
Due to CNS disorder.
o Both pupils are affected – appear constricted.
o Neither pupil react to light(or react poorly)but they both have a near response=light-near
dissociation.
o The pupils are unequal in size, small and irregularly shaped.
o Caused by diabetes, alcoholism and neurosyphilis.
o Parasympathetic defect.