What is Uveitic Macular Edema?

Uveitis is a condition where a part of the eye called the uveal tract becomes inflamed. This can happen at different locations inside the eye and depending on the location, it’s named as anterior, intermediate, posterior or panuveitis (based on a classification system known as the SUN system).

A complication of uveitis, known as Uveitic Macular Edema (UME), causes fluid to build up within the layers of the retina, leading to swelling or thickening of the retina or creating fluid-filled areas known as cystoid spaces. This is primarily caused by the breakdown of a protective barrier known as the blood-retina barrier due to inflammation. This can happen with any type of uveitis and is the most common reason for reduction in vision in cases where the inflammation is at the back of the eye (posterior uveitis), affecting roughly one-third of these cases.

Therefore, detecting and managing this condition early can help to prevent long-lasting eye issues. Uveitis is a serious condition, causing blindness in about 20% of cases in developed countries.

What Causes Uveitic Macular Edema?

Uveitic macular edema is a condition that primarily happens due to noninfectious issues connected with inflammation in the back part of the eye, called the uvea. It’s especially seen in cases of front eye inflammation (anterior uveitis) caused by a genetic marker called HLA B27, which is strongly linked to the development of macular edema, or swollen areas in the center part of the eye’s retina. However, it’s not common to see uveitic macular edema in most cases of anterior uveitis. Some infections can also result in this condition.

This swelling in the macula often happens because of different causes like the following:

1. In anterior uveitis, it can happen due to HLA B27, juvenile idiopathic arthritis (a form of arthritis in children with no known cause), or for unknown reasons.
2. In posterior uveitis, or inflammation in the back part of the eye, it’s seen in conditions like Birdshot retinochoroidopathy (an autoimmune disease affecting the retina), toxoplasmosis (a parasite-caused disease), retinal vasculitis (inflammation of the eye’s blood vessels), CMV retinitis (a viral infection of the retina), and acute retinal necrosis (rapidly progressing retinal inflammation).
3. In panuveitis, where the eye’s entire middle layer is inflamed, it can happen with conditions such as Vogt-Koyanagi-Harada disease (an autoimmune disease that affects vision), sympathetic ophthalmia (a rare disease causing blindness), Adamantiades-Behcet disease, eye infections, sarcoidosis, multifocal choroiditis (an inflammatory disorder of the eye), and immune recovery uveitis among others.
4. In intermediate uveitis, or inflammation of the eye’s peripheral parts, it can happen as part of diseases like Pars planitis, sarcoidosis, multiple sclerosis, tuberculosis, and Lyme disease.
5. Certain eye medications, like brimonidine, metipranolol, prostaglandin analogs, and glucocorticosteroids, can also cause it.
6. Some systemic medications, like sulfonamides, cidofovir, rifabutin, bisphosphonates, and tumor necrosis factor inhibitors.
7. In Irvine–Gass syndrome, macular edema can develop after cataract surgery.

It can also develop due to certain types of cancer, like primary central nervous system (CNS) or eye non-Hodgkin lymphoma, history of travel, or with the use of certain medicines that modulate the immune system such as fingolimod or paclitaxel.

Risk Factors and Frequency for Uveitic Macular Edema

Uveitic macular edema is a condition that often occurs with certain types of uveitis, an inflammation of the eye. It’s more common with posterior, pan, and intermediate uveitis, and less common with anterior uveitis.

Among patients with anterior uveitis, 9% to 28% develop Uveitic macular edema, especially if they also have HLAB27 anterior uveitis.
People with intermediate uveitis have a 20% to 75% chance of also having Uveitic macular edema.
In cases of posterior uveitis, Uveitic macular edema can occur in 19% to 34% of cases.
For those with panuveitis, the likelihood of also having Uveitic macular edema is between 18% and 66%.

In cases of uveitis that aren’t caused by an infection, Uveitic macular edema can be a serious issue that threatens vision and can affect about one in ten patients. It’s the most common severe complication, followed by the development of an epiretinal membrane and glaucoma.

Signs and Symptoms of Uveitic Macular Edema

Uveitis is a type of eye inflammation. Sometimes, those with uveitis experience a decrease in vision. Often, this is due to what’s called “uveitic macular edema”. You might not notice any change in your vision in the early stages. But as it progresses, it can lead to issues like trouble with contrast sensitivity, difficulty reading, distorted vision (metamophopsia), seeing objects smaller than they are (micropsia), and having a blind spot in the field of vision (positive relative scotoma).

To diagnose uveitic macular edema, your doctor will perform a specialized eye examination using a 90D or a 78D lens, along with a microscope for viewing the eye. They’ll look for things such as:

An increase in the thickness of the macula (part of the eye)
Loss of normal reflex in the fovea (center of the eye)
Fluid-filled spaces within the eye (seen sometimes)
A membrane on the surface of the retina (seen in some cases)
A possible haze over the vitreous (the gel-like substance that fills the eye)
Other signs of inflammation like vasculitis, chorioretinitis, choroiditis, swelling of the optic disk (disc edema), inferior snowballs, snow banking, and vitreous traction

The doctor will use a special light called a “red-free” light to better see any fluid-filled spaces and swelling. If the edema is still in the early stages (with a central macular thickness less than 300 μm), it might be hard to see these changes, and other tests might be needed to confirm the diagnosis.

Testing for Uveitic Macular Edema

When you have uveitis, which is an inflammation of the eye, and you notice a drop in your vision, your doctor might suspect macular edema, where fluid and proteins collect on or under the macula of the eye causing it to thicken and swell (edema). To confirm this, your doctor will use imaging methods called optical coherence tomography (OCT) and fundus fluorescein angiography (FFA). These methods can pick up macular edema even when it’s not showing symptoms yet.

The OCT works like an ultrasound but uses light instead of sound to capture detailed images of the eye. This scan can reveal cyst-like spaces in multiple layers of the retina, extra fluid beneath the macula, and the presence of an epiretinal membrane, which is like scar tissue on the retina. OCT can also detect vitreous traction, which is when the clear gel that fills the eye (the vitreous) pulls on the retina. OCT can also show if there’s any inflammation in the deep layers of the eye, which is called choroiditis or chorioretinitis. Hence, OCT serves as a conclusive test and the best method for diagnosing macular edema and aids doctors in monitoring the edema’s improvement or possible recurrence.

FFA is another imaging method where a special dye is injected into the bloodstream and pictures are taken as the dye passes through the blood vessels in the eye. FFA might show swelling of tiny blood vessels around the macula and dye pooling in spaces at the foveola, a tiny pit located in the macula which provides the clearest vision. These spaces can form patterns due to the radial organization of cells in a layer of the retina. In some cases, there may be leakage of smaller blood vessels under the retina at the macula. FFA can also spot enlargement of the foveal avascular zone, an area in the retina that affects vision when oxygen supply diminishes due to restricted blood flow. FFA can also indicate leakage of dye at the optic disc due to active inflammation and detect signs of other eye conditions such as vasculitis, chorioretinitis, areas of limited blood flow and new, abnormal blood vessels growth.

Treatment Options for Uveitic Macular Edema

Uveitic macular edema is a condition affecting the eyes and is initially treated using steroids. Depending on how the patient responds, doctors might use additional drugs to better manage the condition. There are a few treatment options currently available for this condition.

Corticosteroids are first-line treatments, and these are primarily used to reduce inflammation. If the condition affects both eyes, or if it doesn’t improve in one eye after local treatments, oral steroids are given. If the condition affects only one eye or if oral steroids are not appropriate, injectable steroids can be used.
In some cases where more standard treatments don’t work, drugs that are slowly released over time from an implanted device in the eye may be used.

Topical steroids are another option, but these are generally not used solely for treating macular edema. They may be used in combination with other treatments to manage inflammation in the front part of the eye. Some types of topical steroids and non-steroidal anti-inflammatory drugs may help improve the effectiveness of other treatments.

Immunosuppressant drugs are also used in some situations. Antimetabolites like azathioprine and methotrexate inhibit the activities of cells involved in inflammation. Another type of immunosuppressive drug, mycophenolate mofetil, works by inhibiting a specific enzyme that is important for cells in the immune system. A group of immunosuppressive drugs called T-cell inhibitors, such as cyclosporine, can be used if other treatments aren’t working.

In consultation with a rheumatologist, biological drugs like etanercept and infliximab may be used in severe cases of uveitic macular edema where inflammation is not being controlled by other treatments.

Another type of treatment for this condition involves injecting medications that block a protein called vascular endothelial growth factor (VEGF), which plays a role in the formation of new blood vessels. These are sometimes used in cases where uveitic macular edema is not responding to other treatments.

In some cases, surgical intervention may be needed. For instance, if the condition has led to excessive pulling on the macular (central part of the retina) or the formation of dense scar-like tissue, surgery may be required. These are more advanced stages of uveitic macular edema where non-surgical treatments may not be effective.

Uveitic macular edema is a condition that causes swelling in the central part of your retina, called the macula. It’s important to note that this can be caused by various factors. These could be:

Uveitis caused by a new blood vessel growth beneath the retina, which is called a choroidal neovascular membrane.
Uveitis due to an active choroiditis lesion – this means inflammation of the layer of blood vessels and connective tissue in the middle part of the eye.
Uveitis that results from disc edema – swelling in the optic disc of the eye.
Traction, or pulling, caused by an epiretinal membrane – a thin tissue that can form over the macula.
Vitreous traction – this is when the clear gel that fills the eyeball, the vitreous, shrinks and pulls on the retina, causing swelling.

An OCT (Optical Coherence Tomography) is typically used to diagnose these issues because the management is usually surgical.

What to expect with Uveitic Macular Edema

People with a condition called uveitis that also have macular edema are at risk of losing their vision severely or completely. The chances of how severe their vision loss could be is also influenced by other features or conditions associated with the uveitis. For example, if the uveitis is present in the back part of the eye (posterior uveitis), the patient’s vision prognosis is considerably worse, as it can damage and scar a vital part of the eye called the macula.

However, newer treatments, such as long-acting corticosteroid implants placed inside the eye (intravitreal) and treatments that modulate the immune system (immunomodulatory therapy), have greatly improved the visual prognosis for these patients. It is important to bear in mind that long-term use of steroidal and immunosuppressive medicines for treatment can have side effects on both the eyes and the body as a whole.

Reportedly, visual acuity, which relates to the clarity or sharpness of vision, can decrease to less than 20/60 in approximately 35% to 50% of cases due to UME. Besides UME, cataracts may also contribute to vision loss in some patients.

Possible Complications When Diagnosed with Uveitic Macular Edema

If swelling of the central part of the retina (called macular edema) continues for an extended period of time (more than six months), it can lead to changes in his vision. This could involve the formation of cysts, the appearance of minor tears in layers of the retina, or, in rare cases, a full-thickness hole in the retina. Other possible changes include splitting the space within the retina, the growth of fibrous tissue and scars from both the edema and underlying inflammation of the eye (uveitis). Once these scars and fibrous tissues start to form, it is usually not a good sign for the person’s vision. Hence, it’s important to treat the swelling early to avoid these long-term effects.

The possible outcomes from long-term macular edema can be summarized as:

Cyst formation
Minor tears in the retina
In rare cases, a full-thickness hole in the retina
Splitting the space within the retina
Growth of fibrous tissues and scars caused by both the edema and underlying eye inflammation
Poor vision forecast once scars and fibrous tissues form

Given these possible outcomes, we should aim to treat the swelling earlier to prevent these long-term effects.

Preventing Uveitic Macular Edema

Uveitic macular edema is the most common reason for reduced vision in patients with certain types of inflammation in the eye, such as posterior uveitis, panuveitis and recurrent or chronic inflamed conditions like intermediate uveitis or anterior uveitis. If patients notice a gradual decrease in their vision, distorted vision (known as metamorphopsia) or find it hard to distinguish variations in brightness or color (reduced contrast sensitivity), it’s important to get a thorough eye examination.

This condition needs to be detected and treated promptly as if left untreated for too long, it can cause permanent damage to vision. Several tests like optical coherence tomography and fundus fluorescein angiography alongside routine blood tests are required to confirm the diagnosis of this eye inflammation, called uveitis.

Treatment usually involves medications like steroids or therapies that help regulate your immune system; these may be given in the form of injections in the eye. In some rare cases, surgery might be necessary.

Frequently asked questions

The prognosis for Uveitic Macular Edema (UME) has greatly improved with newer treatments such as long-acting corticosteroid implants and immunomodulatory therapy. These treatments have significantly improved the visual prognosis for patients with UME. However, it is important to note that long-term use of these medications can have side effects on both the eyes and the body as a whole.

Uveitic macular edema can occur due to various causes, including anterior uveitis, posterior uveitis, panuveitis, intermediate uveitis, certain eye medications, certain systemic medications, Irvine-Gass syndrome, certain types of cancer, history of travel, and the use of certain medicines that modulate the immune system.

Signs and symptoms of Uveitic Macular Edema include: - Decrease in vision - Trouble with contrast sensitivity - Difficulty reading - Distorted vision (metamophopsia) - Seeing objects smaller than they are (micropsia) - Having a blind spot in the field of vision (positive relative scotoma) In addition to these symptoms, a doctor will look for specific signs during a specialized eye examination to diagnose Uveitic Macular Edema. These signs include: - An increase in the thickness of the macula (part of the eye) - Loss of normal reflex in the fovea (center of the eye) - Fluid-filled spaces within the eye (seen sometimes) - A membrane on the surface of the retina (seen in some cases) - A possible haze over the vitreous (the gel-like substance that fills the eye) - Other signs of inflammation like vasculitis, chorioretinitis, choroiditis, swelling of the optic disk (disc edema), inferior snowballs, snow banking, and vitreous traction To better see any fluid-filled spaces and swelling, a doctor will use a special light called a "red-free" light. However, if the edema is still in the early stages, it might be hard to see these changes, and other tests might be needed to confirm the diagnosis.

The types of tests needed for Uveitic Macular Edema include: 1. Optical coherence tomography (OCT): This imaging method uses light to capture detailed images of the eye and can reveal cyst-like spaces in multiple layers of the retina, extra fluid beneath the macula, the presence of an epiretinal membrane, and vitreous traction. 2. Fundus fluorescein angiography (FFA): This imaging method involves injecting a special dye into the bloodstream and taking pictures as the dye passes through the blood vessels in the eye. FFA can show swelling of blood vessels around the macula, dye pooling in spaces at the foveola, leakage of smaller blood vessels under the retina, enlargement of the foveal avascular zone, and signs of other eye conditions. These tests help diagnose and monitor the condition, as well as determine the best treatment approach.

The doctor needs to rule out the following conditions when diagnosing Uveitic Macular Edema: 1. Uveitis caused by a new blood vessel growth beneath the retina (choroidal neovascular membrane). 2. Uveitis due to an active choroiditis lesion (inflammation of the layer of blood vessels and connective tissue in the middle part of the eye). 3. Uveitis that results from disc edema (swelling in the optic disc of the eye). 4. Traction caused by an epiretinal membrane (a thin tissue that can form over the macula). 5. Vitreous traction (when the clear gel that fills the eyeball, the vitreous, shrinks and pulls on the retina, causing swelling).

When treating Uveitic Macular Edema, there are potential side effects that can occur. These include: - Cyst formation - Minor tears in the retina - In rare cases, a full-thickness hole in the retina - Splitting the space within the retina - Growth of fibrous tissues and scars caused by both the edema and underlying eye inflammation - Poor vision forecast once scars and fibrous tissues form

An ophthalmologist.

Uveitic Macular Edema can affect about one in ten patients.

Uveitic Macular Edema is treated using a variety of methods depending on the severity and response of the patient. The initial treatment involves the use of steroids, either topical or oral, to reduce inflammation. Injectable steroids can be used if the condition affects only one eye or if oral steroids are not appropriate. In cases where standard treatments don't work, drugs that are slowly released over time from an implanted device in the eye may be used. Topical steroids and non-steroidal anti-inflammatory drugs may be used in combination with other treatments to manage inflammation in the front part of the eye. Immunosuppressant drugs like azathioprine, methotrexate, mycophenolate mofetil, and cyclosporine can be used if other treatments aren't effective. In severe cases, biological drugs like etanercept and infliximab may be used. Medications that block a protein called vascular endothelial growth factor (VEGF) may be used if other treatments are not effective. In advanced stages, surgical intervention may be required.

Uveitic Macular Edema (UME) is a complication of uveitis where fluid builds up within the layers of the retina, leading to swelling or thickening of the retina or creating fluid-filled areas known as cystoid spaces.