Symptoms of carotid artery disease frequently present to ophthalmologists. Though these may be sight threatening, they may represent the first signs of life threatening carotid artery stenosis. These include cerebral transient ischaemic attacks (TIA), transient monocular blindness (amaurosis fugax), central or branch retinal artery occlusion, hypotensive retinopathy (previously known as “venous stasis retinopathy”), and ocular ischaemic syndrome (OIS).1

Of these associations with carotid artery disease, OIS presents the most challenging condition for the ophthalmologist with many controversial aspects to its management.

OIS is a severe form of chronic ischaemia of both anterior and posterior segments of the eye as well other orbital structures supplied by the ophthalmic artery. It is thought to be due to chronic hypoperfusion when carotid artery stenosis is greater than 90%.1

OIS is rare; however, ophthalmoscopic features of hypotensive retinopathy have been found in 5%–20%2 of patients with carotid artery occlusive disease and approximately 200 patients with OIS have been reported in the literature by way of case reports, retrospective reviews, and prospective studies.3 Based on a questionnaire survey it has been estimated that a neuro-ophthalmologist or glaucoma specialist encounters at least one case per year.4

In this article we present an overview and recommendations for best clinical practice for OIS based on an extensive review of recent studies.