Retinal vein occlusion and artery occlusion Flashcards
define a retinal vein occlusion
when a thrombus forms in the retinal veins and blocks drainage of blood from the retina
where does the central retinal vein run
thorugh the optic nerve
-is responsible for draining blood from the retina
what are the two main types of retinal vein occlusion
can either be blockage of teh central vein
-this will cause problems with the whole retina
or
block one of the four branches that come together to form the central retinal vein
-this causes problems for the area drained where the blockage is
what does retinal vein occlusion cause
blockage and pooling of blood in the reint a
this results in leakage of fluid and blood causing:
-macular oedema
-retinal haemorrhage
this can cause damage to retina tissue and loss of vision
what does macular oedema and retinal haemorrhages in retinal vein occlusion cause the release of
-what does it do
causes release of VEGF
-stimulated develpoment of new blood vessels (neovascullurisasiton)
presentaiton of retinal vein occlusion 1
sudden painless loss of vision
risk factors for retinal vein occlusion 6
HT
high cholesterol
DM
smoking
glaucoma
systemic inflam conditions eg SLT
what are the characterisitc fundoscopy findings in retinal vein occlusion 3
flame and blot haemorrhages
optic disc oedema
macula oedema
other tests for retinal vein occlusion 6
fundoscopy
full medical history
FBC (for leukaemia)
ESR (inflam marker)
BP
serum glucose
managemnt of retinal vein occlusion 2
referred immediately to ophthalmologist for assessment and management
-treat macular oedema and prevent neovascularization of the retina and iris and glaucoma
Options for
-laser photocoagulation
-intravireal steroids (dexamethasone intravitreal implant)
-anti-VEGF therapies (ranibizumab, afilbercept)
define central retinal artery occlusion
where something blocks the flow of blood through the central retinal artery
describe the vasculature of the eye
central retinal artery supplies the blood to the retina
is a branch of the ophthalmic artery which is a branch of the internal carotid artery
most common cause of central retinal artery occlusion
-other important cause
atherosclerosis
-giant cell arterisits
vasculitis affeting the ophthalmic or central retinal artery causes reduced blood flow
risk factors for central retinal artery occlusion by atherosclerosis
if by athersclerosis risks are the same as other cardiovascular diseases:
-older age
-FHx
-smoking
-alcohol consumption
-hypertension
-DM
-poor diet
-inactivity
-obesity
risk factors for central retinal artery occlusion by giant cell arteritis 5
white ptx
> 50
particularly females
those already affected by giant cell arteritis
polymyalgia rheymatica
presentation of central retinal artery occlusion 1
causes sudden painful loss of vision
compare presenation of central retinal artery occlusion and vein occulsion
vein- painLESS loss of vision
artery- painFUL loss of vision
pupillary relfex testing in central retinal artery occlusion
relative afferent pupillary defect
-where the pupil in the affect eye constricts more when light is shone in the other eye compared when it is shone in the affected eye
-occurs because input is not being sensed by ischemic retina when testing the direct light reflex but is being sensed by the normal retina during the consensual light reflex
what will fundosocpy of central retinal artery occlusion show 2
pale retina with a CHERRY RED SPOT
retina pale due to lack of perfusion with blood
-cherry red spot is the macula which has a thinner surface that shows the red coloured choroid below and contrasts with the pale retina
management of central retinal artery occlusion caused by giant cell arteritis tests-2 management-1
giant cell arteritis is an important reversible cause
-test with ESR and temporal artery biopsy
treat with high dose steroids - pred 60mg
immediate management of central retinal artery occlusion if atherosclerosis cause 4
aim: to try and dislodge the thrombus
examples:
-ocular massage
-removing fluid from anterior chamber to reduced IOP
-inhaling carbogen to dilate the artery
-sublingual isosorbide dinitrate to dilate the artery
long term managemetn of central retinal artery occlusion
treating reversible risk factors and secondary prevention of cardiovascular disease
