Retinal Artery Occlusion

Central retinal artery – majority of inner retina blood circulation.

Cilioretinal artery – 15-30% of the circulation. (cilioretinal artery occlusion happens about 5% cases – watch out for GCA).

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Branch retinal artery occlusion (BRAO):

• 40% of cases.

• Retinal emboli is the cause.

• Painless loss of vision – 3/4 has 6/12 vision or better.

• Sectoral retinal opacification with retinal oedema.

• Monitor for iris neovacularisation (rare).

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Central retinal artery occlusion (CRAO):

• Elderly male.

• Bilateral cases 1-2%.

• Sudden painless loss of vision +/- amaurosis fugax.

• RAPD present

• Rubeosis usually within 4-5 weeks (20% cases).

• Cherry red spot at fovea (cilioretinal artery patent), retinal whitening, arterial attenuation, cattle tracking (emboli), ONH oedema (think of AION).

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Management:

1. Rule out GCA – FBC / ESR / CRP / Temporal artery biopsy / steroids Rx.

2. Carotid Doppler USS

3. Referral to TIA clinic

4. Young patients – hypercoagulable cause – blood test for homocysteine, sickle cell, Factor V Leiden, protein C & S, antithrombin III and antiphospholipid antibody.

5. Conservative treatment

6. Active treatment – window of 4 hours (irreversible damage after onset – retina can withstand ischaemia without damage up to 97 minutes after onset of CRAO) – ocular massage or AC paracentesis to dislodge emboli.