eye basicsa Flashcards
what is the fascia surrounding the eye bal ?
tenons fascia
what parts of the eye are covered by tenon’s fascia ?
the entire eyeball except the cornea
which part of tenons fascia forms the ligament ?
reflection of the fascia on the lateral and meedial rectus muscle form the check ligaments
what are the three main layers compromising the eye ?
the fibrous layer
the vascular layer
nervous layer
what are the components of the fibrous layer ?
sclera and the cornea
what are the features of the cornea ?
avascular
no lymphatics
but has a sensory innervation
what is the limbus ?
the junction between the clear cornea and the opaque sclera
what is the function of thee limbus ?
allows for the migration of new cells to maintain integrity of the cornea
aqueous humor outflow
site of surgical inscision
what compartments are present in the eye
anterior and posterior segment
anterior segment is further divided into the anterior and posterior chamber
what are the contents of each the anterior and the posterior segment ?
the anterior segment contains aqueous humor
the posterior compartment contains vitreous humor
what muscles allow for thee pupillary light reflex to occur ?
pupillary dilator muscles
pupillary constrictor muscles
what muscles are innervated by the oculomotor nerve?
somatic
levator palpebral muscles
superior rectus muscle
medial recutus musclee
inferior oblique
what does argylle’s robertson syndrome describe ?
intact near reflex
loss of pupillary light reflex
when can argylle’s robertson syndrome be seen ?
neurosyphilis
what are the parasympathetic functions of the oculomotor nerve ?
innervation of the ciliary body
allows for constriction of the pupil sphincter pupillae
what are the features of the lens ?
avascular, asensory, onion like lamellar structure
what is cataract ?
affection of thee leens in which it becomes opaque and white in colour
how is the shape of the lens affected ?
1- when the ciliary muscles contract and the suspensory ligaments are lax the lens becomes more globular
2- when the ciliary muscles relax and the suspensory ligaments are taught the lens becomes more flat
what are zonular fibres ?
fibres attached to the lens to keep it suspended
a group of zonular fibres are called suspensory ligament
which muscles aid n the accomodation/near reflex ?
the ciliary muscles
where is the aqueous humor produced ?
by the ciliary body
where is thee aqueous humor normally draineed ?
in the trabecular meshwork and schlemm’s canal
what happens when there is an obstruction in the outflow of thee aqueous humor ?
glaucoma
what are the features that are seen on fundus examination ?
optic disc
macula
retinal vessels
what is the blood supply of the retina and the choroid ?
ophthalmic artery
which comes from the internal carotid artery
what is the venous drainagee of the eye ?
thee superior and inferior ophthalmic vein which drain towards the cavernous sinus in the pterygoid plexus
what is the disease of microaneurysms in relation to the eye ?
diabetes
what are the types of diabetic retinopathies ?
proliferative and non proliferative
what are the contents of the cavernous sinus ?
OTOMAI
oculomotor
trochlear
opthalmic of facial
maxillary of facial
abducens
internal carotid
what test is used to check for strabismus ?
Hirschberg test - corneal light reflex
what are the types of strabismus ?
esotropia
exotropia
hypertropia
hypotropia
what are the possible causes of pseudostrabismus ?
epicanthus
hypertelorism
what is the most common complication of diabetic retinopathy ?
retinal detachment
affection of the limbus
limbal stem cell deficiency
