Retinal artery occlusion

Labelled Diagram of the Eye

Labelled diagram of the structure of the retina

Retinal artery occlusion (RAO) is blockage of an artery supplying oxygenated blood to the retina of the eye, resulting in reduced vision.

Note that a retinal artery occlusion is a type of retinal vascular occlusion (the other type of retinal vascular occlusion being a retinal vein occlusion).

Retinal artery occlusions are a moderately common type of retinal vascular disorder.

It is useful to understand that there are two sources of blood supply to the retina, i.e.

  1. supply through the choroid - which is itself supplied via the ciliary arteries, and
  2. supply via the central retinal artery - which is from the ophthalmic artery and splits into two equal superior (upper) and inferior (lower) branches.

Depending on where in the retinal blood supply system the blockage occurs, different parts of the retina can be affected (or unaffected). Hence the severity of a retinal artery occlusion (RAO) can vary considerably from case to case.

Retinal artery occlusions can be classified according to the location of the blockage in the blood supply to the retina:

Types of retinal artery occlusions:

  • Central retinal artery occlusion (CRAO)
  • Branch retinal artery occlusion (BRAO)
  • Cilioretinal artery occlusion.

Initial symptoms of retinal artery occlusion can include a sudden loss of vision through one eye. In most cases the loss of vision is severe, but not total. In a small proportion of cases, both eyes are affected but not necessarily to the same extent.

Such symptoms alone are not sufficient to indicate retinal artery occlusion (RAO). As for all medical concerns, professional advice should be sought if and when any problems arise - urgently if the issue is severe.

In many cases retinal artery occlusions are ophthalmic emergencies, meaning that treatment must be given within a short time of the appearance of initial symptoms in order for long-term deterioration of sight (in the affected eye) to be avoided.


Retinal artery occlusions are a large and complicated subject - with issues depending on the type of retinal artery occlusion and its causes, and also varying considerably from case to case.

This brief entry is included for completeness to mention a wide range of ophthalmic conditions in this section - for more information ask an expert or consult a more specialized source.

More about Ophthalmology:

This section includes short definitions of many diseases, disorders, and conditions of the eyes and visual system.
For definitions of other terms in this category, choose from the list to the left (but note that this is not a complete/exhaustive list).

Other related pages include

For further information see also our pages of books about ophthalmology.

The following books may also be of interest:

The Aging Eye (Harvard Medical School)
MCQ Companion to the Eye (Textbook)
The Secret of Perfect Vision: How You Can Prevent and Reverse Nearsightedness
What Your Doctor May Not Tell You About(TM) Glaucoma: The Essential Treatments and Advances That Could Save Your Sight

In the News:

Saffron adopted through ABC's Adopt-an-Herb Program - 7 Apr '20

Kale is in season in February - 7 Feb '20

Aromatherapy assoc. NAHA supports lavender via ABC's adopt-an-herb - 22 Dec '19

Garlic and Artichoke adopted through ABC's Adopt-an-Herb Program - 14 Jun '19

Cranberry Harvest underway in USA - 5 Oct '18

Total retail sales of herbal supplements in the USA exceeded $8 Billion in 2017 - 13 Sep '18

It's a bumper blueberry season - 13 Jul '18

Positive effects of exercise on blood cell populations - 20 Jun '18

There are many ways to connect with Angels. Be inspired by books and websites.

Although care has been taken when compiling this page, the information contained might not be completely up to date. Accuracy cannot be guaranteed. This material is copyright. See terms of use.

IvyRose Holistic 2003-2024.