An older patient who has got a blocked retinal blood vessel may have an acute, occlusive central retinal artery occlusion and must be seen urgently in an eye casualty department.
Usually, an acute CRAO presents with a sudden painless and very profound loss of vision, which can be down to about ‘count fingers’ or less. If the cilioretinal artery is present, we may be able to preserve central vision. We described CRAO in an earlier blog post (see below).
In this blog post, I am describing acute branch retinal artery occlusion as this is only a partial vascular occlusion. With a partial vascular occlusion, the patient can preserve much of the visual acuity, often even maintaining as good as 20/20 or 6/6 vision. People who have hypertension, diabetes mellitus, heart disease, arterial disease are at risk of blocking a vein in their eye, and also patients with a condition called giant cell arteritis. Patients who smoke, have palpitations or valvular heart disease, or a history of transient ischemic attacks are also more at risk of vascular occlusion. Branch retinal artery occlusion can also occur in patients who have vasculitis, migraines, sickle cell haemoglobinopathy and other hypercoagulable states.
Although macular oedema can occur if the macula is involved – in a central retinal artery occlusion, more commonly there is ischemia (lack of blood flow) of the retina and macula, which is essentially a stroke of the retina, and vision is severely affected. Branch retinal artery occlusion can also result in macular oedema or ischaemia – but vision is often better than in a central retinal artery occlusion.
Not only should we carry out an eye examination, but an ophthalmologist should also conduct a non-ocular examination paying particular attention to the causes of the acute arterial occlusions which include a complete cardiovascular assessment.
Professor Michel Michaelides and Mr Jaheed Khan are the medical retinal specialists at Clinica London, seeing patients with retinal blood vessel occlusions. Professor Michel Michaelides and Mr Jaheed Khan work very closely with their physician colleagues to detect any obvious cause of an arterial occlusion, particularly in young patients where there may be a vasculitic cause.
Our specialist will need to conduct imaging, using wide-field fundus photography, autofluorescence imaging, optical coherence tomography (OCT) and possibly fluorescein angiography. We see retinal blood vessel occlusion as a mini stroke and a warning that there may be more severe, widespread cardiovascular disease. Hypertension is also a risk factor and these skilled ophthalmic specialists can clinically detect pre occlusion states.
All patients with retinal arterial occlusion need Doppler studies of the carotid arteries as there is about 20% incidence of significant carotid artery stenosis in patients who have had either a central or branch retinal artery occlusion.
Arterial occlusions are where ophthalmology meets cardiovascular disease. At Clinica London, our medical retina specialists are experts in diagnosing vascular occlusions of the retina and advising patients on what further assessments and treatment you may need.