What Is Excess Fluid in Eyes?

The human eye consists of mostly water, collagen, and protein, and it always contains fluid in the form of tears to keep the eye lubricated. However, sometimes the eye develops a buildup of excess fluid. This issue can be caused by a variety of conditions and factors.

As the excess fluid in the eye starts to build up, it can initially mimic symptoms of allergies or puffy eyes from lack of sleep, so it can be easy to overlook or ignore these signs. Eventually, the eye swells enough that vision is affected.

The treatment for excess fluid in the eye depends on the cause, so it's important to determine the underlying cause first. 

In this article, we'll review conditions that can cause excess fluid in the eye, potential causes, and treatment options.

Underlying Conditions that Cause Excess Eye Fluid

There are several types of excess fluid in the eye, depending on the health issue that is causing fluid to build up. Conditions that are known to cause excess eye fluid include, macular edema, diabetic macular edema, central serous retinopathy, macular degeneration, and glaucoma, among others.

Macular Edema

Macular edema occurs when there is an excessive amount of fluid in the macula. The macula is located in the center of the retina—the tissue at the back of the eye that helps you see light—and is responsible for giving you clear, detailed straight-ahead vision. 

The fluid builds up in the macula from damaged blood vessels in the retina. When there is excess fluid in the macula, vision is affected. A common symptom of macular edema is blurry or wavy vision on (or near) the center of your field of vision.

Diabetic Macular Edema

Diabetic macular edema is due to diabetic retinopathy, which is a complication of diabetes. There are two phases of diabetic retinopathy: when the blood vessels in the retina swell and leak (called nonproliferative retinopathy) and when abnormal new blood vessels grow on the retina (called proliferative retinopathy).

Some common symptoms of diabetic macular edema are blurry or double vision as well as dark, floating, or blank spots in your vision.

Because the retina is critical to vision, diabetic retinopathy can lead to vision loss. Controlling your blood sugar levels is one way to reduce the risk of developing the eye condition or having it worsen. 

Central Serous Retinopathy

Central serous retinopathy (also known as central serous chorioretinopathy) is when fluid builds up behind the retina, which may negatively affect vision. The fluid buildup is due to leakage from a layer of tissue under the retina (called the choroid).

When the layer between the retina and the choroid—the retinal pigment epithelium—doesn’t function properly, fluid builds up behind the retina, which, in turn, causes the retina to detach and vision to be impaired. Symptoms can include distorted, dimmed, or blurred vision and straight lines appearing bent or crooked, among others.

Central serous retinopathy has been associated with a handful of conditions, including hypertension, coronary disease, and psychological stress. The causes of central serous retinopathy are not fully understood, but constricted blood vessels and inflammation from stress or vascular conditions may be at play.

Macular Degeneration

Macular degeneration is characterized by the breakdown of the macula, which may be from blood vessels growing from the choroid into the retina. These abnormal blood vessels can leak fluid into the macula, causing macular edema, or build-up of fluid in the macula.

When the macula is damaged, central vision and the ability to see fine details are negatively affected. Macular degeneration is sometimes caused by aging, in which case it is called age-related macular degeneration, or AMD. Age-related macular degeneration is the most common cause of significant loss of eyesight among people aged 50 and older.

Glaucoma

Glaucoma occurs when the eye's drainage system gets clogged, resulting in fluid building up in the eye. This can also happen when the eye produces more fluid than usual and can't drain fast enough. As fluid accumulates, it increases pressure inside the eye, which can damage the nerve fibers responsible for vision. The damaged nerves cause the optic disc to hollow and adopt a cupped shape, which doctors can see during an examination.

There are different types of glaucoma, and symptoms vary. For example, glaucoma can go unnoticed in the early stages as symptoms may not occur. Angle-closure glaucoma, which is when the eye's drainage canals are blocked, causes noticeable symptoms such as severe eye pain and blurred or narrowed field of vision.

If excess fluid continues to accumulate in the eye, glaucoma will likely worsen and may lead to severe loss of vision or blindness.

Other Causes of Excess Eye Fluid

How excess fluid in the eye develops often depends on the condition that is causing fluid buildup. For example, diabetic eye diseases, including diabetic retinopathy and glaucoma, can cause that buildup.

Macular edema can be caused by a range of conditions or occurrences including eye surgery, age-related macular degeneration, or inflammatory diseases that affect the eye.

Choroidal effusion is another possible cause. It is the buildup of fluid between the choroid, a layer of blood vessels on top of the retina, and the sclera, the white outer covering of the eye.

A retinal tear may also cause excess fluid in the eye as fluid accumulates and may even cause the retina to detach due to the contraction of the gel in the eye.

Yet another condition, chemosis, is swelling of the eye due to accumulation of fluid and is often caused by allergies or an eye infection.

The thing to remember is that while the fluid in the eye is normal, excess fluid is not. Excessive fluid is not without cause, and while some of the conditions or occurrences that cause fluid buildup (as described above) cannot be completely prevented, they may be hindered or slowed.

It's important to see an eye doctor if you're having trouble with your vision or excess eye fluid to get a diagnosis and determine the best course of treatment.

Treatment

Just as causes of excess fluid in the eye are dependent on the condition causing it, treatment of excess fluid also depends on what condition is at play. In general, treatments will include decreasing the pressure caused by fluid buildup as well as addressing the underlying cause for the buildup.

For example, in diabetic macular edema, a healthcare provider will likely aim treatment at your diabetes and directly treat damage to the retina that is causing fluid buildup.

In other cases, surgery may be warranted. People with glaucoma may undergo surgery to create a new opening for fluid to drain from. In addition, some medicines help the eye drain fluid, thus reducing the pressure inside the eye, or cause the eye not to make as much fluid.

Because there are many types of excess fluid in the eye and causes vary and may even overlap, it is best to speak with a healthcare professional if you have symptoms of fluid buildup. Once the underlying condition is determined, treatment will be more effective.

A Word From Verywell

Eye health can be managed proactively by seeking eye care and doing regular checkups. While fluid in the eyes is completely normal, excess fluid in the eyes could be a sign of a more serious medical issue.

If you notice excess fluid in conjunction with other symptoms, like blurred vision or severe eye pain, make an appointment with an eye doctor. They can help you get to the root of the issue and point you toward any treatment you may need.