Anterior chamber

The corneal isnormally a clear, dome-like structure. Alex Turton

The anterior chamber of the eye is composed of the space between the iris and the cornea. It is filled with a liquid called aqueous humor. Aqueous humor is produced by the ciliary body. The fluid is cycled up through the anterior chamber and out through a drainage system called the trabecular meshwork. This fluid is constantly produced and drained. This chamber is called anterior because the back part of the eye is called the posterior chamber.


Diseases or conditions that affect the anterior chamber:

  • Glaucoma - Glaucoma is a disease of the optic nerve that is usually, but not always, caused by increased eye pressure (elevated intraocular pressure.) Containing more than a million nerve fibers, the optic nerve connects the eye to the brain. This important nerve is responsible for carrying images to the brain. The optic nerve fibers make up a part of the retina that gives us sight. This nerve fiber layer can be damaged when the pressure of the eye (intraocular pressure) becomes too high. Over time, high pressure causes the nerve fibers to die, resulting in decreased vision. Vision loss and blindness will likely result if glaucoma is left untreated.Glaucoma has been nicknamed the "sneak thief of sight" because it often goes undetected and causes irreversible damage to the eye. This pressure is usually caused by the ciliary body making too much aqueous humor or the trabecular meshwork, the drainpipe of the eye, can not filter the fluid out fast enough
  • Pigmentary Dispersion Syndrome - Pigmentary dispersion syndrome (PDS) is a disorder often detected during a routine eye examination. PDS occurs when pigment from the back of the iris, the colored part of your eye, is slowly released into the internal fluid that fills the front part of the eye. This fluid, called aqueous humor, carries the pigment in a cyclic manner through the front part of the eye and out to the eye's drainage canal, called the trabecular meshwork. If enough pigment is released, it can begin to plug up this drainage canal and prevent the fluid from flowing out properly. When this occurs, the pressure inside the eye may build up and cause pigmentary glaucoma.
  • Hyphema - Hyphema is a term used to describe bleeding in the anterior chamber of the eye, the space between the cornea and the iris. Hyphema occurs when blood leaks into the clear fluid of the aqueous humor. This pooling of blood is usually visible to the naked eye and causes decreased vision. Hyphema is usually caused by trauma to the eye. It may be the result of an injury from a flying object, a ball, a stick, an elbow to the eye, a fall or a fight. Hyphema may also be associated with surgical procedures. Other causes include abnormal vessel growth in the eye and certain ocular tumors.
  • Hypopyon - A hypopyon is a collect of white blood cells and inflammatory material settles in the bottom of the anterior chamber when the eye has a condition called uveitis. It may sound like a condition caused by the sun's UV rays, but uveitis (yoo-vee-eye-tis) is actually an inflammation or swelling of the eye's uvea. The uvea is located in the center of the eye, between the sclera and the retina. It is responsible for supplying blood to the retina. When a hypopyon exists, usually the aqueous humor is thick and filled with inflammatory cells and debris. If it becomes very thick, eye pressure will increase.

    Depth of the Anterior Chamber

    Doctors are generally interested in the depth of the anterior chamber. The depth is measured from the back layer of the cornea to the​ front surface of the lens. The average depth of the anterior chamber is about 3.15 mm. If the depth of the anterior chamber is shallow, it narrows the angle that the iris makes with the cornea. If this angle becomes very narrow, a person could be at risk for narrow angle glaucoma or acute angle closure glaucoma. The depth of the anterior chamber is also very important for certain eye surgeries including cataract and glaucoma surgery.

    How Doctors View the Anterior Chamber

    The anterior chamber can be viewed by several different methods. 

    • Slit Lamp Examination - A slit lamp is an upright biomicroscope that eye doctors use to view the eye under high power magnification. Doctors can also use a slit lamp to inspect the aqueous humor that circulates in the anterior chamber.
    • Gonioscopy - Gonioscopy is a procedure using a gonioscope or goniolens used together with a slit lamp by an optometrist or ophthalmologist to view the front part of the eye between the cornea and the iris. The goniolens is usually placed directly onto the cornea. Although gonioscopy is painless, an anesthetic eye drop is placed into the patient's eye to improve comfort and decrease anxiety.
    • Scheimpflug Imaging - Scheimpflug imaging is a technique to image the anterior chamber and allows doctors to precisely measure the depth of the anterior chamber using a type of rotating camera.
    • Optical Coherence Topography - Optical coherence tomography (OCT) is a noninvasive imaging technology used to obtain high resolution cross-sectional images of the retina. OCT is similar to ultrasound testing, except that imaging is performed by measuring light rather than sound. 

    Continue Reading