Ocular and systemic causes of retinopathy in patients without diabetes mellitus

• Flame-shaped haemorrhages
• Blot and dot haemorrhages
• Cotton wool spots
• Retinal oedema

• Disc swelling
• Tortuous and dilated retinal veins
• "Blood and thunder" appearance in CRVO

• Anterior and posterior segment neovascularisation with time especially in ischaemic CRVO
• Ischaemic CRVO may present with relative afferent pupillary defect and poor visual acuity
• Features present over distribution of involved vein (all 4 quadrants in CRVO)

• Exact pathogenesis unknown and multifactorial. 
• Thrombosis of affected vein and mechanical obstruction at arterio-venous junctions (especially in BRVO) are primary factors
• Resultant stasis of blood, and ischaemia in some instances, causing retinopathy

• Blot and dot haemorrhages 
• Flame-shaped haemorrhages
• Cotton-wool spots

• Generalised arteriolar narrowing
• Focal arteriolar narrowing
• Arterio-venous nicking

• History of hypertension

• Increased retinal arterial blood pressure causing endothelial damage and arteriosclerosis leading to leakage and retinal ischaemia

• Blot and dot haemorrhages 
• Cotton-wool spots

• Arterial narrowing 
• Venous dilatation
• Retinal artery occlusion 
• Retinal emboli 

• History of cardiovascular disease and risk factors
• Carotid artery stenosis (>90%) usually, but not always, present

• Carotid vessel occlusion leading to retinal ischaemia causing cotton-wool spots, neovascularisation and leaking (haemorrhages)

• "Salmon-patch" haemorrhages
• Cotton-wool spots

Neovascularisation at the optic disc of periphery (sea fan-shaped)

• "Iridiscent spots"
• "Black sunbursts"

• Non-proliferative sickle cell retinopathy usually asymptomatic due to peripheral involvement of retina

• Reticulocytes and dense sickle and non-sickle cells causing retinal arterial obstruction leading to ischaemia; severe occlusion may lead to proliferative retinopathy

• Cotton-wool spots
• Blot and dot haemorrhages

• Optic disc oedema 
• Vitreous haemorrhage

• Drug history (cytotoxics, chloramphenicol, penicillamine etc.)
• History of radiation; long-term infection (e.g. parvovirus, TB)

• Anaemia leading to retinal ischaemia causing retinopathy

• Hard exudates 
• Microaneurysms
• Blot and dot haemorrhages 
• Cotton-wool spots

• Marked vascular sheathing
• Telangiectasia

• Dispersion of retinal pigment epithelium causing "salt-and-pepper" appearance

• History of cranial/ maxillary radiation

• Direct radiation-induced retinal vascular endothelial damage causing leakage (haemorrhage) and ischaemia

• Cotton-wool spots
• Blot and dot haemorrhages
• Flame-shaped haemorrhages

• Telangiectasia
• BRVO
• CRVO

• Number of cotton-wool spots in AIDS patient may correlate with systemic progress of the disease and decreased cerebral blood flow

• Blockage of retinal vessels due to circulating immune complexes and other HIV-related clotting anomalies leading to ischaemia and retinopathy

• Cotton-wool spots
• Blot and dot haemorrhages

• Central retinal arterial occlusion
• CRVO
• BRVO

• One third of hospitalised SLE patients have non-diabetic retinopathy
• Presence of non-diabetic retinopathy associated with active SLE disease

• Attachment of immunoglobulins and complement to vessel wall leading to microangiopathy, small retinal vessel occlusion and ischaemia

• Blot and dot haemorrhages
• Cotton-wool spots

• Leukaemic infiltrates

• May be difficult to distinguish from effects of anaemia

• Anaemia, thrombocytopenia and hyperviscosity leading to retinal vessel occlusion and ischaemia