Medical retina Flashcards
What is ARMD?
Many factors eg smoking, genetic predisposition, vitamin deficiency, UV light result in accumulation of VEGF and decrease in macular pigment
Photoreceptor death and build up of drusen
What occurs in dry ARMD?
Atrophy of layers of the macula
Pigment discolouration
Drusen deposition
What occurs in wet ARMD?
Neovascularisation in the choroid (behind the retina)
Leakage of fluid, lipids and blood into layers of the retina causing scar tissue and damage to retinal cells
10% of ARMD
What is the pathogenesis of diabetic retinopathy?
Retinal arteriole occlusion due to: 1. basement membrane thickening 2. endothelial cell damage 3. RBC changes 4. Platelet stickiness increased
Retinal arteriole / venule leakage due to: loss of pericytes
What are the consequences of leakage in diabetic retinopathy?
Chronic leakage
Retinal oedema
Hard exudate
What causes cotton wool spots?
Secondary to ischaemia from retinal arteriole occlusion
Nerve fibre layer infarct
What is the treatment for proliferative diabetic retinopathy?
Anti-VEGF injections
LASER
NB is rarely symptomatic (unless haemorrhage has occurred, late stage) so screening is very important
What is the pathophysiology of retinal vein occlusion?
Venous occlusion Stagnation Hypoxia Oedema and haemorrhage Increased extravascular pressure Stagnation etc Can be branch or central
What are causes of retinal artery occlusion?
Atherosclerosis
GCA
Prothrombotic state eg thrombophilias
What is a PVD?
Normal ageing process
Vitreous comes away from the retina and can cause floaters and flashing lights
1 in 10 develop retinal tear, which can lead to retinal detachment
What are the complications of diabetic retinopathy?
Vitreous haemorrhage
Retinal detachment (scar tissue formation)
Glaucoma (new blood vessels at front of the eye)
