Retinal vein occlusion and artery occlusion

Question 1

define a retinal vein occlusion

Answer 1

when a thrombus forms in the retinal veins and blocks drainage of blood from the retina

Question 2

where does the central retinal vein run

Answer 2

thorugh the optic nerve
-is responsible for draining blood from the retina

Question 3

what are the two main types of retinal vein occlusion

Answer 3

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

Question 4

what does retinal vein occlusion cause

Answer 4

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

Question 5

what does macular oedema and retinal haemorrhages in retinal vein occlusion cause the release of
-what does it do

Answer 5

causes release of VEGF
-stimulated develpoment of new blood vessels (neovascullurisasiton)

Question 6

presentaiton of retinal vein occlusion 1

Answer 6

sudden painless loss of vision

Question 7

risk factors for retinal vein occlusion 6

Answer 7

HT

high cholesterol

DM

smoking

glaucoma

systemic inflam conditions eg SLT

Question 8

what are the characterisitc fundoscopy findings in retinal vein occlusion 3

Answer 8

flame and blot haemorrhages

optic disc oedema

macula oedema

Question 9

other tests for retinal vein occlusion 6

Answer 9

fundoscopy

full medical history

FBC (for leukaemia)

ESR (inflam marker)

BP

serum glucose

Question 10

managemnt of retinal vein occlusion 2

Answer 10

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)

Question 11

define central retinal artery occlusion

Answer 11

where something blocks the flow of blood through the central retinal artery

Question 12

describe the vasculature of the eye

Answer 12

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

Question 13

most common cause of central retinal artery occlusion
-other important cause

Answer 13

atherosclerosis

-giant cell arterisits
vasculitis affeting the ophthalmic or central retinal artery causes reduced blood flow

Question 14

risk factors for central retinal artery occlusion by atherosclerosis

Answer 14

if by athersclerosis risks are the same as other cardiovascular diseases:
-older age
-FHx
-smoking
-alcohol consumption
-hypertension
-DM
-poor diet
-inactivity
-obesity

Question 15

risk factors for central retinal artery occlusion by giant cell arteritis 5

Answer 15

white ptx

> 50

particularly females

those already affected by giant cell arteritis

polymyalgia rheymatica

Question 16

presentation of central retinal artery occlusion 1

Answer 16

causes sudden painful loss of vision

Question 17

compare presenation of central retinal artery occlusion and vein occulsion

Answer 17

vein- painLESS loss of vision

artery- painFUL loss of vision

Question 18

pupillary relfex testing in central retinal artery occlusion

Answer 18

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

Question 19

what will fundosocpy of central retinal artery occlusion show 2

Answer 19

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

Question 20

management of central retinal artery occlusion caused by giant cell arteritis tests-2 management-1

Answer 20

giant cell arteritis is an important reversible cause
-test with ESR and temporal artery biopsy

treat with high dose steroids - pred 60mg

Question 21

immediate management of central retinal artery occlusion if atherosclerosis cause 4

Answer 21

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

Question 22

long term managemetn of central retinal artery occlusion

Answer 22

treating reversible risk factors and secondary prevention of cardiovascular disease