6. clinical relevance: eye (lecture) Flashcards
how does raised intracranial pressure affect the eye?
can lead to Papilledema
secondary to raised ICP
what is Papilledema?
swelling of the optic disc, visible during ophthalmoscopy
Pathophysiology of Papilledema?
The high pressure within the cranium resists venous return from the eye, causing fluid to collect in the retina, producing a swollen optic disc
when viewing the optic disc, which structures are medial and which are lateral?
optic disc medial
macula / fovea lateral
what is the fovea / macula?
area of most acute vision
what is retinal detachment?
retina has detached from fibrous outer layer (sclera and choroid)
what can retinal detachment lead to?
retina requires blood supply (avascular structure)
if left too long, can lead to irreversible partial blindness as retina has been teared away from choroid (middle vascular layer)
what can cause retina detachment?
trauma to head / face and surrounding orbit, causing retina to detach from choroid (middle vascular) and sclera (outer fibrous)
what is significant about the optic nerve?
a continuation of the brain itself - contains the meninges
what are the layers of the meninges? (superficial to deep)
DAP:
Dura mata
Arachnoid mata
Pia mata
what runs through the middle of the optic nerve?
central retinal artery (+ vein)
what is central retinal artery a branch of?
opthalmic artery, supplying eyeball
what can inflammation to the brain cause?
photophobia
why does inflammation to the brain cause photophobia?
all the areas inflamed around the optic nerve (meninges inflamed), so bright light impulses can cause inflamed layers to become painful
what do the lens of the eyes divide?
anterior from posterior SEGMENT
