Macular Oedema

Macular oedema is swelling in a small but vital area at the back of your eye that affects your ability to see fine details and read clearly, but with proper treatment and monitoring, many people can reduce the swelling and protect their vision.

Table of contents

• What is macular oedema?
• Symptoms of macular oedema
• What causes macular oedema?
• How is macular oedema diagnosed?
• Treatment options
• Managing and preventing progression

What is macular oedema?

Macular oedema is swelling in part of the retina (the light-sensitive layer of tissue at the back of your eye)^[1]. The swelling occurs specifically in an area called the macula, which is the central part of the retina responsible for your sharpest vision^[2].

The macula helps you see fine detail, faraway objects, and color. It contains more light-sensitive cells than any screen or monitor, making it essential for activities like reading, driving, and recognizing faces^[12]. When fluid builds up in this area from leaking or damaged blood vessels, the macula thickens and enlarges, distorting your vision^[4].

Macular oedema can cause the macula to swell up to over 500 microns in thickness^[2]. The condition is not a disease itself, but rather a symptom that results from other underlying eye or health conditions^[12].

• Retina
• Macula
• Blood vessels of the retina

Symptoms of macular oedema

Blurry vision and vision that gets worse over time are the main symptoms of macular oedema^[1]. The blurriness may be mild at first and not interfere with your daily activities, but it can progress to make reading, driving, or performing detail-oriented tasks that require looking forward more difficult^[3].

You may also notice several other changes to your vision, including:

• Objects look wavy, especially when you look straight ahead^[1]
• Objects look like they’re different sizes if you look out of one eye and then the other^[1]
• Colors look dull or faded^[1]
• A dark spot in the center of your field of vision^[6]
• Objects appear dim, dark, or misshapen^[5]

If you only have macular oedema in one eye, it may take longer for you to notice changes to your vision^[1]. Sometimes there is very little or no blurring when the macular oedema is very mild or if it does not involve the most central part of the macula^[2].

For some people, macular oedema only causes mild blurry vision. For others, it causes more severe central vision loss, which can make it hard to do everyday activities like reading and driving^[1].

What causes macular oedema?

Macular oedema happens when blood vessels leak into the macula. This makes the macula swell, causing blurry vision^[1]. The swelling occurs when the retina’s ability to absorb fluid is overwhelmed by the fluid leaking into it^[12].

Many different conditions can cause macular oedema. Understanding the underlying cause is important because it determines which treatment will be most effective.

Common causes

Diabetic retinopathy is the most common cause of macular oedema. This is an eye condition that causes vision loss in people with diabetes. When diabetic retinopathy causes macular oedema, it’s called diabetic macular edema (DME)^[1]. High blood sugar levels damage the small blood vessels in the retina, causing them to swell and leak fluid into the macula^[3].

Age-related macular degeneration (AMD) is another significant cause. In a certain type of AMD called wet (or neovascular) AMD, abnormal blood vessels in the macula leak fluid into or under the retina, which can cause swelling in the macula^[1].

Blocked veins in the retina (retinal vein occlusion) can lead to macular oedema. When veins in the retina are blocked, blood can’t drain the way it should and it leaks into the macula, which can cause swelling^[1]. This condition is often associated with poorly-controlled high blood pressure, high cholesterol, and diabetes^[7].

Other causes

Several other conditions and situations can lead to macular oedema:

• Uveitis: Inflammation inside the eye that happens when the immune system attacks eye tissue. It can cause swelling in any part of the eye, including the macula^[1]
• Eye surgery: Some people develop macular oedema after having surgery to treat another eye condition, like cataracts. This swelling is often mild, but it’s still important to get treatment right away to help prevent future vision loss^[1]
• Retinitis pigmentosa: A genetic disease. Some people with this condition can also have swelling in the macula^[1]
• Certain medicines: Some medicines, like medicines to treat glaucoma, can cause macular oedema as a side effect^[1]
• Eye trauma: Injury to the eye can damage retinal blood vessels, leading to fluid leakage^[2]

How is macular oedema diagnosed?

Eye doctors can check for macular oedema as part of a dilated eye exam. The exam is simple and painless. Your doctor will give you some eye drops to dilate (widen) your pupil and take a look at the retina^[1].

If your doctor thinks you have macular oedema, they may do more tests to confirm the diagnosis and understand its severity. The most common diagnostic tests include:

Optical coherence tomography (OCT)

OCT has become one of the best ways to diagnose and identify macular oedema^[5]. This noninvasive test uses a special light to create a high-resolution cross-sectional image of the retina^[5]. It can show the swollen area of the macula at the back of the eye and provide a measurement of how abnormally thickened the macula is^[2].

Fluorescein angiography

This test lets the doctor see pictures of the blood vessels in your retina^[1]. Your doctor will inject a special dye into your arm. The dye travels through your bloodstream from your arm to your eye, and a special camera system identifies leaking blood vessels and the macular oedema that might come with it^[5].

Examination with a slit lamp

Macular oedema can be detected or suspected by an optometrist or ophthalmologist through an internal examination of the eye using eye drops to dilate the pupil and a machine called a slit lamp to look at the back of the eye^[2]. A special lens may be used to see your macula and identify the swelling^[5].

Treatment options

Treatment for macular oedema depends on what’s causing your condition. The goal of treatment is to reduce the swelling and prevent vision loss. With treatment, your vision will likely improve^[5].

Medications

Several types of medications can be used to treat macular oedema:

Anti-VEGF injections are a common treatment. Macular swelling causes the VEGF protein in your body to produce blood vessels at a rapid rate, resulting in the growth of abnormal blood vessels that are prone to breaking and leaking blood and fluid. Anti-VEGF injections help to block these proteins from producing abnormal blood vessels, thereby reducing fluid leakage and swelling^[9]. These medications include aflibercept (Eylea), bevacizumab (Avastin), and ranibizumab (Lucentis)^[9].

The treatment may involve regular but quite painless injections of drugs into the eye^[2]. These thin-needle injections are typically given once a month for the first six months^[9].

Corticosteroids (steroids) target inflammation in the body and may be prescribed to reduce retinal swelling^[9]. They can be given as steroidal or nonsteroidal anti-inflammatory eye drops, injections into the eye, or implanted during a surgical procedure^[4][5]. Ozurdex is one medication licensed for treatment of macular oedema due to inflammation^[2].

Other eye drops: For macular oedema associated with certain inherited retinal diseases, eye drops such as Dorzolamide (Trusopt) or tablets such as Acetazolamide may be used^[2]. Drugs that treat eye pressure may also help the swelling to decrease^[5].

Laser treatment

Laser treatment can help seal the blood vessels in the retina to stop the leaking and bring down the macular swelling. This procedure, called focal-grid macular laser surgery, involves laser burns performed to stop leaks of fluid and blood or to shrink abnormal blood vessels^[4][9].

Surgery

Vitrectomy is a surgical procedure where blood vessels, blood, and scar tissue are removed from the vitreous gel in the eye^[4][5].

Treatment outcomes

A research study following patients for five years found that treatment for macular oedema due to retinal vein occlusion yielded vision gains, although many patients required ongoing treatment. The study showed that macular oedema from retinal vein occlusion can be successfully treated with continued monitoring and individualized therapy^[11].

It can take weeks or months for macular oedema to heal^[6]. In some cases, if someone can really manage their blood sugar and blood pressure effectively through lifestyle changes, they may be able to avoid getting started on a series of eye injections^[19].

Managing and preventing progression

While medical treatments are important, lifestyle changes play an essential role in managing macular oedema and preventing it from worsening, especially in cases related to diabetes.

Blood sugar management

One of the single most effective ways to combat vision loss from macular oedema is to improve your blood sugar management^[19]. If you have diabetic retinopathy, managing your diabetes can help prevent or delay vision loss^[1]. This includes making a habit of checking your blood sugar throughout the day to find patterns, understanding how your medication works and taking it as prescribed, and quitting smoking^[19].

Blood pressure control

When you have diabetes, you’re more likely to have high blood pressure, which can worsen macular oedema. Lowering your blood pressure can reduce your chances of further illness^[17]. Weight loss, limiting alcohol, regular exercise, and stress reduction can all help keep blood pressure in check^[17].

Diet and exercise

Being active, moving your body more, and clean eating can help manage many health problems^[19]. To get the most benefits for your eyes, exercise for at least 150 minutes a week. Even moderate exercise helps. Any movement works, like taking a walk, riding a bike, going for a hike, or doing water aerobics^[17].

A healthy and balanced diet helps keep your blood pressure and blood sugar in check^[17]. Your plate should include vegetables and fruit (half your plate), protein (a quarter of your plate), and whole grains (a quarter of your plate). Avoid drinks with a lot of sugar; drink water, coffee, or tea instead. It’s also important to cut back on salt—experts suggest no more than 1,500 milligrams of sodium daily, or around three-fourths of a teaspoon^[17].

Quitting smoking

The nicotine in cigarettes and other products may worsen your diabetes and eventually cause you to have eye problems, including blindness. Kicking a smoking habit can help curb these negative effects on your health^[17].

Regular eye exams

If you have diabetic retinopathy, it’s important to get a dilated eye exam at least once a year^[1]. Early detection of macular oedema significantly enhances the prospects of preserving vision and halting disease progression^[18]. Follow-up care is a key part of your treatment and safety^[6].

Working with healthcare providers

Getting connected to the right healthcare providers can make a big difference^[19]. Your primary care provider is the team captain who will make sure you’re getting your annual diabetes-related exams^[19]. You may need to see a retina specialist, an ophthalmologist trained in retinal diseases, to receive specialized treatment^[5].

Living with vision changes

If you experience vision loss from macular oedema, low vision aids can help improve your quality of life. These may include magnifying glasses, reading glasses with magnifying lenses, handheld magnifying glasses, and stand magnifiers for reading books^[15]. A low-vision specialist can evaluate your current eye function and recommend strategies for maximizing your remaining vision^[15].