Central Retinal Artery Occlusion

Question 1

Risk Factors for Central Retinal Artery Occlusion (2).

Answer 1

1. Any Risk Factor of Atherosclerosis.

2. Any Risk Factor of Giant Cell Arteritis (White Female Above 50 with PMR).

Question 2

Aetiology of Central Retinal Artery Occlusion (2).

Answer 2

1. Atherosclerosis.

2. Giant Cell Arteritis (Vasculitis) that can affect the Ophthalmic or Central Retinal Artery to reduce blood flow.

Question 3

Arterial Supply of Retina (3).

Answer 3

1. Central Retinal Artery.
2. Branch of Ophthalmic Artery.
3. Branch of Internal Carotid Artery.

Question 4

Clinical Presentation of Central Retinal Artery Occlusion.

Answer 4

Sudden painless loss of vision (blockage of Central Retinal Artery).

Question 5

CENTRAL RETINAL ARTERY OCCLUSION vs. Central Retinal Vein Occlusion (2).

Answer 5

1. Faster Onset.

2. Less Commoner.

Question 6

Examination Findings of Central Retinal Artery Occlusion Patients (3).

Answer 6

1. RAPD.
2. Fundoscopy :
   2A : Pale Retina - Lack of Perfusion with Blood.
   2B : Cherry Red Spot - Macula which has a thinner surface that shows the red-coloured choroid below and contrasts with the pale retina.
   3 : Heavy association with CVD - cardiovascular signs e.g. Carotid Bruits, Hypertension.

Question 7

Relative Afferent Pupillary Defect Aetiology.

Answer 7

Sign : The pupil in the affected eye constricts more when light is shone in the other eye (compared to when it is shone in the affected eye.

The input is not being sensed by the ischaemic retina when testing the direct light reflex.

The input is being sensed by the normal retina (of the other eye) when testing the consensual light reflex.

Question 8

Management of Central Retinal Artery Occlusion (due to Atherosclerosis) (2).

Answer 8

1. Immediate Management (no strong evidence base - attempts to dislodge the thrombus).
   A. Ocular Massage.
   B. Removing Fluid from Anterior Chamber to Reduce IOP.
   C. Inhaling Carbogen (5% CO2 and 95% O2) to dilate artery.
   D. Sublingual Isosorbide Dinitrate to dilate artery.
2. Long-Term management (treat reversible risk factors and focus on secondary prevention of CVD).