What is retinal vascular occlusive disease?

• A group of eye conditions caused by the blockage of blood vessels that supply the retina with oxygen and nutrients
• It is also known as retinal vein or artery occlusion
• Can lead to vision loss and are typically associated with underlying systemic health issues
• The blockage can occur in different vessels in the retina, as detailed below:

Sub-types of retinal vascular occlusive disease:

1. Central Retinal Artery Occlusion (CRAO)
   • A severe subtype of retinal vascular occlusive disease
   • Involves the sudden blockage of the central retinal artery, which supplies blood to the inner retinal layers
   • The blockage is caused by an emboli which may be a small blood clot or cholesterol deposit
   • It can result in a sudden and severe loss of vision in the affected eye
2. Branch Retinal Artery Occlusion (BRAO):
   • Affects a smaller portion of the retina compared to CRAO
   • Involves the blockage of one of the branches of the central retinal artery
   • Can still lead to significant vision loss in the affected area
3. Central Retinal Vein Occlusion (CRVO):
   • Occurs when the central retinal vein, responsible for draining blood from the retina, becomes blocked
   • Blockages in retinal veins can cause the accumulation of fluid in the retina due to insufficient blood flow out of the eye
   • There are two types of CRVO: ischaemic, which is associated with more severe vision loss, and non-ischaemic, which typically results in milder symptoms
   • Often arises due to factors like hypertension and diabetes
4. Branch Retinal Vein Occlusion (BRVO):
   • Involves the blockage of one of the branches of the central retinal vein
   • Affects a smaller area of the retina
   • Can be caused by various factors, including atherosclerosis (thickening/hardening of arteries), diabetes, and glaucoma

What are the treatment options for retinal vascular occlusive disease?

• Medical management of the underlying systemic condition such as hypertension, diabetes and high cholesterol
• If blood clots are the underlying cause of vascular occlusion, anticoagulant therapy (blood thinners) may be considered to prevent further clot formation
• Intravitreal anti-VEGF eye injections to reduce retinal swelling and improve vision
• Laser therapy (photocoagulation) to reduce retinal swelling, prevent the growth of abnormal blood vessels and seal leaking blood vessels
• Retinal surgery may be required in severe cases of CRAO or BRAO to dislodge the emboli or restore blood flow through microsurgical techniques
• The prognosis for retinal vascular occlusive diseases varies depending on the subtype, the extent of the blockage, and the timeliness of intervention
• Early detection and prompt treatment are critical factors in preserving vision and preventing further damage