Asteroid Hyalosis

What is asteroid hyalosis?

Asteroid hyalosis (AH) is an eye condition that causes you to develop tiny, glittering yellow particles or flecks inside your eyes. It’s usually harmless, and most cases don’t need any treatment.

The particles that develop with AH form inside the vitreous, the clear, gel-like substance inside your eyes. AH affects only one eye at a time in more than 80% of cases.

Despite its classification as a permanent and degenerative condition, most people don’t know they have it. That’s because it doesn't usually affect your vision or cause symptoms. The glittering effect inside the eye is hard to spot unless you shine a light directly at the affected eye and look closely.

Eye floaters (myodesopsias) sometimes appear in your vision due to AH crystals. Floaters are common after you turn 50, and they’re usually a normal effect of the aging process. The key difference between the two is that AH involves glittering particles in your eyes, While eye floaters can happen without those particles.

How common is asteroid hyalosis?

Experts consider AH common overall. It’s most common in people over age 60, and people are more likely to develop it as they get older.

What are the symptoms of asteroid hyalosis?

AH rarely causes symptoms. Most people only learn they have it when a healthcare provider notices the reflection of the particles while looking into their eyes. That’s most likely to happen during a routine physical exam or when seeing an eye care specialist for an eye exam.

When symptoms do happen, they’re usually mild. Most people experience slightly clouded vision or greater numbers of eye floaters (myodesopsias).

What causes asteroid hyalosis?

Experts aren’t sure why AH happens. They know a bit about what exactly is happening, though.

Asteroid bodies contain minerals like calcium and phosphorus, plus fatty compounds called lipids. The crystals that make up asteroid bodies have similarities to gallstones and kidney stones. Some researchers suspect that there’s a link between AH and the conditions or circumstances that cause kidney stones or gallstones to form, but more research is necessary to confirm this.

Asteroid bodies are extremely small. On average, they’re about 180 micrometers in diameter, but they can be as little as 3 micrometers wide or as large as 280 micrometers wide. (For context 1,000 micrometers can fit in 1 millimeter, and the average human hair is about 100 micrometers in diameter.)

Asteroid bodies don’t sink to the bottom of your eye because the vitreous is gel-like. Much like pieces of fruit suspended in a gelatin dessert, the asteroid bodies linger in roughly the same place. Moving your eyes may cause them to wobble or flutter around, but they generally stay where they are.

What are the risk factors for asteroid hyalosis?

There are two main contributing factors that researchers can identify.

• You’re more likely to develop AH if you’re over 60.
• Men and people assigned male at birth (AMAB) account for about 60% or more of those with AH.

There’s evidence that people with AH are more likely to have certain conditions or circumstances. They include:

• Type 2 diabetes.
• High cholesterol (hyperlipidemia).
• High blood pressure (hypertension).

Experts aren’t sure if these conditions cause AH, but studies have found that people with these conditions seem more likely to have AH.

How is asteroid hyalosis diagnosed?

The glittering reflection of asteroid bodies is often visible with the naked eye alone. A healthcare provider may also notice AH during a standard exam with a simple hand-held device called an ophthalmoscope. These devices have a small light immediately underneath a magnifying window your provider looks through.

An eye care specialist, such as an optometrist or ophthalmologist, can also diagnose AH during a routine eye exam.

What tests will be done to diagnose this condition?

A simple look into your eyes is usually all it takes to diagnose AH. An eye care specialist may also use a slit lamp exam, but asteroid bodies might be harder to see this way. A slit lamp uses brighter light than an ophthalmoscope, and the additional light just means there’s more light to reflect off the asteroid bodies (similar to how high-beam headlights in thick fog make it harder to see).

While those tests are often enough to diagnose AH, your provider may recommend additional tests to rule out other conditions that can have similar effects to AH. The tests they may recommend include:

• Fluorescein angiography: This test can help providers detect issues like new blood vessel growth due to diabetes-related retinopathy.
• Optical coherence tomography: This test can also help diagnose diabetes-related retinopathy or spot other issues like glaucoma, tumors in your eye or macular conditions.

How is asteroid hyalosis treated?

In most cases, AH doesn’t need treatment.

Usually, treatment is only necessary when AH is severe enough to cloud your vision. If that happens, an eye surgery known as vitrectomy is the treatment. This procedure involves removing the cloudy vitreous contents from your eye and replacing it with something else that can do the job in the meantime.

Some of the likely replacements are saline fluid, silicone oil or a gas bubble. All of these help your eye maintain its shape. Silicone oil may need a follow-up procedure to remove that oil. Saline or a gas bubble don’t need a follow-up procedure because your body will gradually replace them with new vitreous fluid.

Complications/side effects of treatment

Vitrectomy is a surgery, so complications are possible. Some of the possible complications include:

• Infection.
• Bleeding.
• Eye pain.
• Torn or detached retina.
• Cataracts (new or worsening).
• Needing follow-up eye surgery.
• Blindness or vision loss (these are rare).

How soon after treatment will I feel better?

The recovery time for a vitrectomy is usually two to four weeks, but some effects may take longer. For example, if you have a gas bubble placed in your eye, it can take several weeks for your body to replace it with new vitreous fluid.

Is asteroid hyalosis preventable, or can I lower my risk of developing it?

AH happens unpredictably and for reasons experts don’t yet understand. That means there’s no way to prevent or reduce your risk of developing it.

What can I expect if I have asteroid hyalosis?

Most people who have AH don’t know they have it. Most cases don’t cause symptoms.

If you have more severe AH, you may notice larger numbers of floaters in your vision or a slight clouding of your vision. While these symptoms aren’t dangerous, they might be annoying or make it harder to see in certain circumstances.

How does long asteroid hyalosis last?

AH usually develops after age 60. Once it happens, it’s permanent unless you undergo a vitrectomy to replace the vitreous in your eye.

What’s the outlook for asteroid hyalosis?

While AH is technically a degenerative condition, meaning it gets worse over time, it still doesn’t cause symptoms for most people. Because of that, experts consider AH a benign (harmless) condition.

How do I take care of myself?

If you have gradual vision changes, especially clouding or decreased vision, you should see an eye care specialist. They can determine what’s causing the change and how to treat it (if necessary).

Most people with AH don’t have symptoms and don’t need treatment. For them, their life after diagnosis has little or no difference from life before. Your eye care specialist can tell you more about what you can do to care for your eyes and minimize or prevent further issues.

When should I see my healthcare provider, or when should I seek care?

If you have AH, you’ll need regular follow-up appointments with your eye care specialist. They’ll tell you how often you should have your eyes checked. Your provider can tell you if you need more frequent follow-up visits to monitor for eye changes or issues.

When should I go to the emergency room?

AH isn’t a dangerous condition and doesn’t cause complications. But AH can happen along with more serious conditions. You should get immediate medical attention if you experience any of the following vision symptoms, issues or changes:

• Sudden vision loss.
• Sudden flashes of light (photopsia).
• Black spots or floaters, especially when you notice a sudden appearance of them or an increase in their numbers.
• Darkening vision (either affecting part or all of your vision).

Why is the word ‘asteroid’ in the name of this condition?

“Asteroid hyalosis” might sound like an astronomical problem, but that’s because of an ancient language quirk. “Asteroid” is from ancient Greek and it means “starlike.” When viewed with a light up close, the particles in your eye look like stars in the night sky.

A note from Cleveland Clinic

If you notice a gradual increase of floaters in your eyes or a gradual clouding of your vision, you should see an eye care specialist. They’ll examine your eyes for any signs of what’s causing the change. If they find that you have asteroid hyalosis, your provider will likely check for other eye conditions that can happen with it.

Asteroid hyalosis (AH) typically happens to people older than 60. Fortunately, the glittering effect is usually the only way you know you have it. Most people don’t have symptoms and don’t need treatment. For most, the only thing that changes is they become starry-eyed.