Choroidal Effusion Causes and Treatment

Choroidal effusion is a buildup of fluid between the choroid (the blood vessel layer that nourishes the overlying retina) and the sclera, the white outer covering of the eye.

Close-up image of a woman's eye
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To learn more about a choroidal effusion, one must learn what the difference between the sclera, choroid and the retina. The sclera is the tough outer coating of the eyeball. The sclera is what gives the eyeball its white appearance. The choroid is the blood vessel-rich tissue that feeds and nourishes the overlying retina. The retina is the light-sensitive tissue that collects light information and transmits it to the brain via the nerve fiber bundles via the optic nerve.

A choroidal effusion is an abnormal accumulation of fluid in the space between the sclera and the choroid. The fluid begins to separate the sclera from the choroid and retina. Usually, there is no space at all between the sclera and the choroid.


Conditions that may cause a choroidal effusion are:

  • Complication from glaucoma surgery (most common)
  • Intraocular surgery
  • Inflammatory disease
  • Trauma
  • Abnormal masses in the eye
  • Drug reactions
  • Venous congestion

Glaucoma surgery is the most common cause of a choroidal effusion because of hypotony brought on by the surgery. Hypotony is when the internal eye pressure is too low. Once a choroidal effusion begins to occur, the situation gets worse because the effusion itself causes a reduction in how much fluid the eye makes. It also increases uveoscleral outflow of fluid. Uveoscleral outflow is another, usually normal, method the eye uses to drain excess fluid in the front part of the eye.


Serous: Serous effusions can involve a small amount of fluid accumulation with no ill side effects. Larger effusions may actually cause one to become temporally nearsighted or have blind spots in their vision.

Hemorrhagic: Hemorrhagic effusions can cause an abrupt onset of pain and decreased vision. With hemorrhagic effusion, the fluid that accumulates is blood.


Choroidal effusions are usually diagnosed by dilating the eye and visualizing the inside of the eye. Doctors will see an elevation in the periphery with a four-lobed appearance. This appearance is usually common because of firm attachments that the choroid has with the veins that drain that area of the retina. A type of ultrasound, called a B-scan can help doctors tell the difference between a choroidal effusion and a true retinal detachment.


While optometrists and ophthalmologists usually diagnose the effusion, most often they are treated by a fellowship-trained retinal specialist. Many times, a retinal specialist will be conservative and simply observe the effusion as sometimes they resolve on their own as the eye pressure gradually rises. If there is significant inflammation, the doctor will prescribe topical and oral steroid medications. Cycloplegic medications are also prescribed because they act to deepen the anterior chamber. In more severe cases, surgical intervention is required. The retinal specialist will drain the fluid with a small opening called a sclerotomy.

2 Sources
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  1. American Academy of Ophthalmology. EyeNet Magazine, Nov 2012. Choroidal Effusions.

  2. Schrieber, C, Liu, Y. Choroidal effusions after glaucoma surgery. Curr Opin Ophthalmol 2015, 26:135–142 doi:10.1097/ICU.0000000000000131

By Troy Bedinghaus, OD
Troy L. Bedinghaus, OD, board-certified optometric physician, owns Lakewood Family Eye Care in Florida. He is an active member of the American Optometric Association.