Eye Tutorial (Lotsa Buzzwords) Flashcards
is the top or bottom lid of the eye more important?
top
why do bacteria commonly colonise in the meibonian glands?
very oily - an ideal environment for colonisation
where is the meibonian gland’s location?
in the tarsal plate behind eyelashes
what fruit is the orbit said to resemble?
a pear
what controls the opening of the eyelid
levator palpebrae superioris superior rectus (muller's muscle)
what controls closing of the eyelid?
orbicularis oculi
what nerve innervates the LPS
CN3
what nerve innervates the orbicularis oculi
CN7
3 classic symptoms of horner’s syndrome
ptosis- eye droop
miosis- tiny pupil
anhydrosis- sweat gland failure
what muscle isn’t working in horner’s syndrome to cause ptosis?
muller’s muscle
innervation of mullers muscle?
sympathetic
what determines whether an eye cellulitis is preseptal or orbital?
if it is anterior (preseptal) or posterior to the orbital septum
cellulitis of what region is the most serious?
orbital
where is the orbital septum located?
posterior to the orbicularis oculi
is orbital cellulitis sight threatening?
yes
what part of the orbicularis oculi is responsible for closing the eye?
orbital part
what part of the orbicularis oculi is responsible for blinking?
palpebral
where is the lacrimal sac located?
immediately medial to the lacrimal punctum
where is the lacrimal gland located?
supralateral to the eye on the brow bone
what innervation is needed to facilitate tear production?
trigeminal nerve (CNV1)
list the 3 phases of the tear film from anterior to posterior?
lipid phase
aqueous phase
mucus phase
if both eyes are affected in an eye presentation, what is the most likely cause?
allergy
if one eye is affected in an eye presentation, what is the most likely cause?
inflammation
how to tell the difference between orbital and preseptal cellulitis?
orbital will present with a defined border around the orbit and a runny nose indicative of sinusitis
motor supply to the tear film?
CN7 parasympathetic
what covers the inner surface of the eyelids?
palpebral conjunctiva
what kind of conjunctiva lines the eyeball?
bulbar conjunctiva
what kind of conjunctiva contains follicles and papillae?
palpebral
baby/old person with a thick watery eye that isn’t red?
blocked tear duct (lacrimal duct obstruction)
best way to manage a blocked tear duct?
massage the area to break down membranes
how can you have a watery eye due to dry eyes?
lacrimal gland oversecretes tears in response to the dryness
how to treat solidified meibonian gland secretions?
warm them to “melt” them
cause of a dry eye in diabetics?
sensory neuropathy
the conjunctiva is self-healing T or F
T
why is the palpebral conjunctiva very vascular?
to allow entry of O2
where in the eye does deep conjunctivitis present?
limbus
symptom of a deep conjunctivitis?
photophobia
what is a fornix?
inner red part of eyelid
where can follicles be found in the eye?
inferior fornix of the palpebral conjunctiva
if there are bilateral follicles on the eye with a red eye what would you suspect?
adenoviral conjunctivitis
if there are unilateral follicles on the eye with a red eye what would you suspect?
chlamydial conjunctivitis
name the main layers of the cornea from anterior to posterior
epithelium
stroma
endothelium
preauricular nodes sore on 1 side during exam on someone with a red eye?
adenoviral conjunctivitis
what part of the cornea contains collagen? how is it arranged?
stroma
regularly spaced
what part of the cornea can regenerate?
epithelium
why are the cells arranged the way they are in the cornea?
maintains clarity of the cornea
cataract at what part of the lens is worst?
back
how is the lens divided in cataract surgery
USS vacuum aspirate
how does the lens attach to the ciliary body?
zonules
how does the lens relax for acute vision?
sympathetic fibres decrease the tension of zonular fibres
name the outer and inner part of the lens
cortex - outer
nucleus - inner
main 3 parts of the uvea?
iris
ciliary body
choroid
main roles of the uveal tract?
provides pigment and nutrition
name the 4 layers of the eye from anterior to posterior
retina
uvea
sclera
cornea
which part of the lens is curved and which is flat?
front is flat
back is curved
findings of uveitis on slit lamp examination?
cells and flare
only a few uveal structures are pigmented T or F
F, all are
where does aqueous humour drain to?
canal of schlemm
does vitreous humour regenerate?
not very well
name the response of a pupil getting light shone in it
direct response
name the response of the pupil next to the one getting light shone in it
consensual response
where does the sympathetic pathway of the eye end?
hypothalamus
what nerve is in charge of dilating the pupil?
long ciliary nerve
what nerve is in charge of constricting the pupil?
short ciliary nerve
what are the ciliary nerves a branch of?
CNV1
causes of horners syndrome and why?
pancoast tumour brain tumour trauma carotid artery dissection = all affect the sympathetic pathway to the eye
3 elements of the accommodation reflex
convergence of the eyes
pupillary constriction
contraction of the ciliary muscle
what effect does contraction of the ciliary muscle have on the zonule fibres
decreases their tension
name the only 2 muscles of the eye not supplied by CN3 and their innervations
superior oblique- CN4
lateral rectus- CN6
presentation of 3rd nerve palsy on examination
eye facing inferolaterally with ptosis
management of new onset painful horners syndrome?
emergency scan, could be a stroke
complications of horner’s syndrome?
stroke
consequences of 3rd nerve palsy and why?
aneurysms due to possble occlusion of the posterior communicating artery
where does the trochlear nerve arise from?
dorsal aspect of the brainstem
what nerve palsy produces a palsy of the contralateral muscle?
trochlear nerve CN4
why can hydrocephalus cause CN4 palsy?
trochlear nucleus lies just below the cerebral aqueduct
via which foramen does CN4 enter the eye?
superior orbital fissure
does CNV1 convey the afferent or efferent arm of the eye?
afferent
what nerve supplies the tip of the nose?
CNV1
what nerve supplies the side of the nose?
CNV2
if hutchison’s sign is present on the tip of the nose, where should you look next and why?
cornea as it is also innervated by CNV1 and may also be affected by shingles
where does CN6 arise from?
pons
role of the abducens nerve on the eye?
motor innervation to lateral rectus
main cause of CN6 nerve palsy and why?
raised intracranial pressure
very thin nerve and is easily stretched
which eye nerve experiences palsy more than the others?
CN6
how to tell which eye is the squint?
shint a light directly in the middle, look at which eye is looking directly at the light
what is the common tendinous ring?
a fascial ring that holds the tendons of each eye muscle
symptoms of optic neuritis
painful eye movements
poor colour vision
main imaging used in opthalmology?
MRI (for soft tissue)
where in the retina do cones and rods lie
cones = in middle, on fovea rods = in periphery
why does optic neuritis cause pain on eye movements?
optic nerve sheath is attached to the common tendinous ring
strongest muscle of all the recti/
MR
what muscle is affected by a blowout fracture?
IR
what epithelium covers the pigmented epithelial cells of the retina
cuboidal
how long do you have to treat an end artery occlusion?
90 mins
what happens to the nasal retinal fibres at the optic chiasm?
they cross over
what happens to the temporal fibres at the optic chiasm?
continue ipsilaterally
the opthalmic artery is a branch of what?
internal carotid artery
the opthalmic artery is an end artery T or F
T
“vascular tunic which supplies the outer layers of the retina”
choroid
quick management of an occlusion?
vasodilate -> digital massage if finger, breath into paper bag
paracenthesis once in hosp
most common cause of an opthalmic artery occlusion?
carotid artery embolis from stroke/stenosis
how to analyse the optic disc
CCC
cup- what does the middle of it look like
colour
contour- is it defined?
signs of CRAO on fundoscopy?
milky retina
cherry red spot
how to tell what eye you’re looking at on fundoscopy?
disc on left = left eye
is a CRAO or CVO sometimes asymptomatic?
CVO
dies a CRAO or CVO look worse on endoscopy?
CVO
new floaters, flashing lights, no pain and change of vision in someone with a past surgery?
retinal detachment
what eye pathology commonly has horseshoe tears?
retinal detachment
Ix for suspected orbital blowout fracture?
CT
how to tell difference between arteries and veins on fundoscopy
arteries more silver and small
veins thicker and redder
