Retinal Macroaneurysms

What are retinal macroaneurysms?

Retinal macroaneurysms are dilatations of the wall of the retinal arterial network. They range in size from 100 to 250 μm in diameter and appear most often on the temporal side of the retina.

Page contents

1. What are retinal macroaneurysms?
2. How is it diagnosed?
3. What is the right treatment?
4. What symptoms do macroaneurysms cause?
5. Prognosis: what to expect
6. Who is at risk and why
7. The two main forms: exudative and haemorrhagic
8. Conditions it can be confused with
9. The tests needed, in detail
10. Treatment in detail
11. General health: as important as treating the eye
12. Follow-up: how often and what we check
13. When you need an urgent examination
14. Macroaneurysms and microaneurysms: what is the difference?
15. Anticoagulants, aspirin and bleeding in the eye
16. Checking your vision at home
17. Daily life with a macroaneurysm
18. Questions worth asking your doctor
19. How vision develops after a haemorrhage
20. After healing: is further follow-up needed?
21. How to prepare for the examination
22. The importance of early diagnosis
23. Diet and lifestyle for healthy blood vessels
24. Frequently Asked Questions about Retinal Macroaneurysms

They are caused by weakening of the vessel wall, which makes it widen and leak. Consequently, the most common findings are oedema and exudates around the aneurysm.

How is it diagnosed?

The diagnosis is made by clinical examination and confirmed with fluorescein angiography and optical coherence tomography (OCT).

What is the right treatment?

Treating a macroaneurysm requires particular care, and because the condition is quite rare, doctors’ experience and the available studies are limited. I personally had the opportunity to treat a number of patients with macroaneurysms in Oxford and to see the different treatment each one needed, depending on the stage of the condition. A common risk is that over-treatment causes not only the macroaneurysm but also the artery that supplies the retina beyond the lesion to become blocked.

With proper monitoring and treatment, the chances of losing vision can be reduced significantly.

What symptoms do macroaneurysms cause?

Many macroaneurysms cause no symptoms at all and are discovered by chance during a fundus examination, especially when they are far from the centre of vision. Symptoms appear when the swollen arteriole leaks or bleeds near the macula:

• Gradual blurring or distortion of central vision, when fluid and lipid exudates collect in the macula.
• Sudden loss of vision without pain, when the aneurysm bleeds. The blood may lie in front of, within or beneath the retina.
• A shadow or floaters, when blood passes into the vitreous.

Macroaneurysms occur more often in people over 60 with high blood pressure, and more often in women. Any sudden loss of vision in one eye needs an examination the same or the next day, as retinal vein occlusion or wet macular degeneration can look similar.

Prognosis: what to expect

The prognosis is often favourable. Many macroaneurysms thrombose and close on their own within weeks or months, while the blood and fluid are gradually absorbed.

Final vision depends mainly on whether the centre of the macula was affected:

• When the lesion is far from the centre, vision is usually unaffected or recovers.
• When there is oedema or exudates at the macula, treatment with laser or intravitreal injections helps limit the damage.
• When blood collects under the macula, the risk of permanent loss of vision is greater and surgery may be needed.

Follow-up is with fundus examination and optical coherence tomography (OCT) at intervals set by the ophthalmologist. Controlling blood pressure in collaboration with your GP or cardiologist is just as important, since macroaneurysms are often a sign of strained blood vessels. Recurrence at the same site is rare, but a new aneurysm may appear on another vessel.

Who is at risk and why

Retinal macroaneurysms occur mainly in older people, usually after 60, and are more common in women. In most cases they affect only one eye, although in a small percentage they appear in both.

The most important risk factor is high blood pressure, which is present in the great majority of patients. Chronic high blood pressure strains the walls of the small arteries of the eye, which lose their elasticity and bulge at a weak point, like a small “bubble” on the vessel. Other factors include arteriosclerosis, high cholesterol and cardiovascular disease in general. For this reason, the diagnosis of a macroaneurysm is also a signal to check your general health.

The two main forms: exudative and haemorrhagic

Exudative form

The macroaneurysm slowly leaks fluid and lipids through its wall. Yellowish exudates form around it, often in a ring shape, along with retinal oedema. As long as the leakage is far from the centre, the patient may have no symptoms at all. However, when the fluid and exudates reach the macula, vision gradually blurs and the image may become distorted.

Haemorrhagic form

The aneurysm ruptures and causes a haemorrhage. A characteristic feature of macroaneurysms is that the blood can spread into several layers at once: in front of the retina, within it, beneath it and sometimes into the vitreous. The patient notices a sudden drop in vision or a dark spot in the visual field. Although it looks dramatic, the bleeding often causes the aneurysm itself to thrombose and “close”.

Conditions it can be confused with

The appearance of a macroaneurysm, especially when there is a large haemorrhage, can resemble other serious conditions of the fundus. The correct diagnosis is crucial, because the treatment is fundamentally different:

• Wet macular degeneration, which also causes bleeding under the retina in older people.
• Polypoidal choroidal vasculopathy, a variant of macular degeneration with haemorrhages and exudates.
• Branch retinal vein occlusion, which causes haemorrhages and oedema in one sector of the retina.
• Diabetic retinopathy, with microaneurysms and exudates, usually in both eyes.
• Choroidal tumours, when a dark subretinal haemorrhage looks like a mass.

The tests needed, in detail

Diagnosis begins with a dilated fundus examination. Imaging tests then confirm the diagnosis and guide treatment:

• Optical coherence tomography (OCT): Shows whether there is fluid at the macula, which layer the haemorrhage is in and how thick the retina is. It is the test used to monitor progress.
• Fluorescein angiography: With an intravenous dye, the aneurysm fills and shows clearly as a bright spot on the artery, together with the leakage around it.
• Indocyanine green angiography: Useful when dense haemorrhage hides the aneurysm, because it “sees” through blood and helps identify choroidal conditions.
• OCT angiography: Images the blood vessels without a dye injection.
• Fundus photography: Records the initial appearance for comparison at later visits.

At the same time, we measure blood pressure at the clinic and recommend assessment by a GP or cardiologist.

Treatment in detail

Monitoring

Many macroaneurysms, especially those that do not threaten the macula or have already bled, close on their own through thrombosis and fibrosis within a few months. In these cases the right choice is close monitoring with OCT, without any intervention that could damage the artery.

Laser photocoagulation

When exudative leakage threatens or has reached the centre of vision and does not settle, laser can be applied around the aneurysm or directly to it to stop the leakage. Great care is needed with the dose, because intense treatment on the artery can block it and cut off the blood supply to the part of the retina it feeds.

Intravitreal injections

Anti-VEGF medicines reduce leakage and macular oedema. They are used alone or combined with laser, especially when the aneurysm is very close to the centre and laser would be risky. Find out more about intravitreal injections.

Managing large haemorrhages

• Haemorrhage in front of the macula: In selected cases, a YAG laser is used to make a small opening so that the blood drains into the vitreous and clears the centre of vision.
• Haemorrhage under the macula: Blood in this position can permanently damage the light-sensitive cells within a few days. An early gas injection may be needed, sometimes with a medicine that dissolves the clot, together with special head positioning, so that the blood moves away from the centre.
• Vitreous haemorrhage that does not clear: This is treated with vitrectomy.

General health: as important as treating the eye

Because macroaneurysms are closely linked to high blood pressure, controlling it properly reduces the risk of new aneurysms and also protects the blood vessels of the heart and brain. Measure your blood pressure at home, take your medicines as prescribed and discuss cholesterol, smoking and physical activity with your doctor. The eye is the only place in the body where we can see the arteries directly, and whatever it shows deserves attention.

Follow-up: how often and what we check

After diagnosis, visits are frequent at first, every 4 to 6 weeks, with an OCT scan at each visit. Once the aneurysm has closed and the oedema has settled, check-ups become less frequent. Exudates are absorbed slowly, over months, and vision may continue to improve for quite some time. At every visit we also examine the other eye.

When you need an urgent examination

• A sudden drop in vision in one eye
• A dark spot appearing in the centre of the visual field
• Many new floaters or a feeling that “something is hanging” in front of the eye
• Recent distortion of straight lines

Macroaneurysms and microaneurysms: what is the difference?

The two names sound alike, but they describe different things. Microaneurysms are tiny bulges in the capillaries, the finest blood vessels of the retina. There are usually many of them, they appear in both eyes and they are the first sign of diabetic retinopathy. Macroaneurysms, by contrast, are larger bulges in the retinal arteries, usually single and in one eye, and are mainly linked to high blood pressure. The distinction matters, because the course, treatment and general health check-up are different.

Anticoagulants, aspirin and bleeding in the eye

Many patients with a macroaneurysm take aspirin or other anticoagulants for their heart or to prevent stroke. A haemorrhage in the eye may be larger when the blood is “thin”, but you should never stop these medicines on your own. The risk to the heart or brain is usually far more serious than the benefit to the eye. Any decision to change them is made together with your cardiologist or GP, once they have been informed of the findings at the back of the eye.

Checking your vision at home

Between visits, you can check the central vision of each eye yourself with the Amsler grid, a simple sheet of squares with a dot in the centre. Wear your reading glasses, close one eye and look at the dot from reading distance. If some lines look wavy, blurred or missing, or if this is new compared with last time, contact the clinic. Another way is to look with each eye separately at a straight line, such as a door frame or the bathroom tiles.

Daily life with a macroaneurysm

Most patients carry on with their activities as normal. Gentle exercise, such as walking, is good for blood pressure and the blood vessels. It is best to avoid intense effort while holding your breath, such as lifting very heavy objects, in the first few weeks after a haemorrhage, until your doctor tells you the condition has stabilised.

For driving, what counts is vision with both eyes together. When one eye has suddenly become blurred, judging distances can be difficult in the first few days. If you do not feel confident, do not drive until you have been examined.

Questions worth asking your doctor

• Has the macroaneurysm already closed or is it still leaking?
• Is the centre of my vision, the macula, affected?
• Do I need treatment now or is it safer to wait?
• How often will I have check-ups and with which test?
• Which symptoms should make me come in sooner?
• Do I need to see a GP or cardiologist, and what should I tell them?

How vision develops after a haemorrhage

After a haemorrhage from a macroaneurysm, the initial picture is often frightening for the patient: a large dark area that hides part or all of the central visual field. The good news is that blood in the vitreous or in front of the retina is gradually absorbed, usually within a few weeks to a few months, and vision improves as the eye “clears”.

Final vision depends mainly on whether the blood or fluid reached the area beneath the centre of the macula and how long it stayed there. When the macula has not been significantly affected, many patients regain very good vision. When there is dense haemorrhage under the centre, early intervention within the first few days gives the best chance.

After healing: is further follow-up needed?

Once a macroaneurysm has closed, it rarely reopens. However, the risk of a new aneurysm appearing elsewhere or in the other eye does not disappear, especially if blood pressure remains uncontrolled. An annual fundus examination, together with good blood pressure control, is the best protection.

How to prepare for the examination

The examination for a macroaneurysm almost always includes dilating the pupils, so come with someone and do not drive afterwards. Bring a list of your medicines, especially anticoagulants and blood pressure medication, and recent blood pressure readings if you have them. If fluorescein angiography has been scheduled, let us know about any allergies, kidney disease or pregnancy. The dye can make the skin slightly yellowish and the urine more strongly coloured for a day, which is expected and harmless.

The importance of early diagnosis

Many macroaneurysms are found by chance during a routine eye examination, before they cause any symptoms. This allows time to control blood pressure and monitor the aneurysm safely. If you have high blood pressure, an annual fundus examination is a simple and worthwhile investment in your vision.

Diet and lifestyle for healthy blood vessels

There is no special diet that cures a macroaneurysm, but whatever benefits the heart also benefits the blood vessels of the eye. Cut down on salt, which raises blood pressure, and choose vegetables, fruit, pulses, fish and olive oil, in the spirit of the Mediterranean diet. Maintain a healthy weight, limit alcohol and stop smoking, which directly damages artery walls. Regular activity, even 30 minutes of walking on most days, helps considerably with blood pressure control.

If you already have high blood pressure, an upper-arm blood pressure monitor at home and a simple notebook of your readings, morning and evening for a few days before each visit, give your doctor a much more reliable picture than a single measurement at the clinic. Bring your notes to the ophthalmologist too, so they can be related to what we see at the back of the eye and the risk can be assessed more accurately.

In any of the urgent situations mentioned above, call +30 210 677 0007 for an examination as soon as possible.

Frequently Asked Questions about Retinal Macroaneurysms

Medically reviewed by: Dr. Vasileios Skouteris MD, FEBO