Glossary of Terms

Aqueous Humor

Fluid made in the ciliary body that provides nutrients for internal structures such as the lens and the cornea. If this fluid is made faster than it can leave the eye then the eye pressure increases leading to glaucoma.

Anterior Chamber

Fluid-filled space inside the eye between the iris and the innermost corneal surface.

Anterior Chamber Angle

Junction of the front surface of the iris and the back surface of the cornea, where aqueous fluid filters out of the eye.(see trabecular meshwork).


Brachytherapy is radiation treatment delivered by a small plaque sewn to the outside of the eye or sclera.


The vascular layer of the eye lying between the retina and sclera. This layer furnishes nourishment to outer layers of the retina.

Ciliary Body

A ring of tissue inside the eye composed of ciliary muscle, which is involved in lens focusing and control of the intraocular pressure. There are also ciliary processes that produce aqueous.


The transparent front segment of the eye that covers the iris, pupil and anterior chamber, and provides most of the eye’s optical power.


Damage to the optic nerve often due to increased pressure in the eye.


Colored tissue lying behind the cornea that gives color to the eye (e.g., blue eyes, brown eyes) and controls the amount of light entering the eye by varying size of the black pupillary opening.

Laser Photocoagulation

This procedure is done by the delivery of a critically focused beam of laser light to the interior of the eye by a fiber optic light source. This procedure is done wherein the blood vessels are cauterized by the heat from a fine-point laser beam of light.


Transparent, intraocular tissue that helps bring rays of light to focus on the retina. A cataract is a lens that has become cloudy or opaque.


The centralized area of the retina responsible for acute central vision necessary for reading and detail work.

Optic Nerve

The primary sensory nerve of the eye. It carries impulses for sight from the retina to the brain.

Photodynamic Therapy

Photodynamic Therapy is the process of blood coagulation in the retina through medicine given intravenously and then followed up at specific times with laser light activation.


A black circular opening in the center of the iris that regulates the amount of light that enters the eye.


The part of the eye that converts images from the eye’s optical system into electrical impulses sent along the optic nerve for transmission to the brain. The retina lines the rear two-thirds of the eye and consists of layers that include rods and cones. This part of the eye can be compared to film in a camera.

Rubeotic Glaucoma

High pressure in the eye due to blockage of the trabecular meshwork by abnormal blood vessels usually doe to diabetes or vein occlusion.


The white protective outer layer of the eye.

Scleral Buckle

Scleral buckle is a surgical procedure used to repair retinal detachment or other retinal pathology.

Trabecular Meshwork

The area in the anterior chamber angle through which the fluid (aqueous humor) leaves the eye. This area is critical in the treatment of glaucoma.

TTT Laser

Transpupillary Thermotherapy (TTT) is a procedure in which a low dose of infrared light is used to treat abnormal blood vessels usually due to age related macular degeneration.


Vitrasert implant is a pellet of ganciclovir, an antiviral medicine, which is inserted into the eye during surgery.


Vitrectomy is a surgical procedure that removes the vitreous humor, a clear gelatinous substance, from the eyeball. This is done to remove blood or scar tissue or repair retinal detachment.

Vitreous (Vitreous Humor)

Transparent, colorless, gelatinous material that fills the rear two-thirds of the interior of the eyeball, between the lens and the retina.


Fibers that suspend the lens from the ciliary body and hold it in position.