Table from [here](x-devonthink-item://E3D816B5-653D-4DC6-A389-8C69022A6062?page=2). see also [[Painful loss of vision]] and [[Visual fields]]
| diagnosis | history | exam |
| --------------------------------------------------------------- | -------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------- |
| [[Central retinal artery occlusion]] | - sudden onset<br>- history of [[Atrial fibrillation]] <br>- other thrombo-embolic condition | - [[Relative afferent pupillary defect\|RAPD]]<br>- retinal pallor on fundoscopy<br>- visual acuity <6/60 |
| [[Central retinal vein occlusion]] | - sudden onset<br>- history of diabetes, HTN | - large areas of haemorrhage on fundoscopy<br>- abnormal [[red reflex]] |
| [[Retinal detachment]] | - preceding flashes/floaters<br>- myopia | - abnormal red reflex<br>- mobile detached retina may be seen on fundoscopy / USS |
| [[Giant Cell Arteritis]] / arteritic ischaemic optic neuropathy | - temporal headaches<br>- fevers, night sweats<br>- jaw claudication<br>- myalgias | - [[Relative afferent pupillary defect\|RAPD]]<br>- tender temporal artery<br>- optic disc oedema |
| macular degeneration | - sudden loss of vision<br>- central vision<br>- distorsion of straight lines | |
| [[Vitreous haemorrhage]] | | |
**Transient**
- migriane
- amurosis fugax
- cerebral TIA
**persistent**
- vascular
- CRAO
- CRVO
- temporal arteritis
- vitreous haemorrhage
- neurological
- peripheral: optic neuritis
- central: cerebral stroke
- globe
- retinal detachment
- acute glaucoma
# [[Central retinal artery occlusion|CRAO]] vs [[Central retinal vein occlusion|CRVO]]
| | CRAO | CRVO |
| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------ |
| vision loss | - sudden **painless** loss of vision<br>- "curtain coming down"<br>- may have poor central vision<br>- blurred vision or sudden onset blindness | - **painless** vision loss varies from slight to severe ; not as sudden as CRAO (onset over minutes)<br>- blurred vision due to macular oedema |
| retina | - pale<br>- **cherry-red spot** at fovea | - retinal haemorrhages, dilated veins, oedema "**blood and thunder**" <br>- venous dilation / tortuosity<br>- macular oedema |
| causes | - embolic<br>- vasculitis<br>- vasospasm<br>- sickle cell<br>- trauma<br>- glaucoma | - thrombosis (DVT of the eye)<br>- hypercoaguable / hyperviscosity <br>- orbital tumours<br>- HTN<br>- [[Glaucoma]]<br>- diabetes<br>- atherosclerosis |
| prognosis | poor | good |