Glaucoma FAQs and definitions are listed below to assist you in a better understanding of this complex disease process. Please contact Glaucoma Associates of Texas if you have any questions.
Glaucoma FAQs (Frequently Asked Questions)
A diagnosis of glaucoma can be shocking and worrisome for many of our new patients. We've compiled a variety of topics that is important for new glaucoma patients, their family, and their concerned friends. The goal of this information is provide a better understanding of glaucoma by all.
Cataract Extraction in Patients with Glaucoma
How is this done?
Compliance with Glaucoma Treatment
How important is it to comply with my Glaucoma treatment?
Childhood (Congenital) Glaucoma
Can glaucoma occur in infants?
What is dry eye?
Exercise and Glaucoma
Can I still be active if I have glaucoma?
Glaucoma Trabeculectomy Suregry Information
What do I need to do before and after my trabeculectomy?
Heredity and Glaucoma
Is glaucoma genetically passed (from one generation to another)?
What is neovascular glaucoma, who's at risk, and how is it treated?
Glaucoma Terms and Definitions
Aqueous Humor: The fluid produced within the front part of the eye.
Bleb: A bubble within the tissue overlying the new drainage opening created during surgery.
Central Vision: What is seen when you are looking straight ahead or reading.
Ciliary Tissues: Tissues located around the lens of the eye that supply nourishing fluid to the eye.
Conjunctiva: A thin, clear membrane that lines the inner surface of the eyelids and the outer surface of the eyeball, except for the cornea.
Cornea: The clear part of the eye located in front of the iris. Part of the eye’s protective covering.
Drainage Canals: Small openings around the outer edge of the iris, which provide the final pathway for fluid to leave the inside of the eye. Sometimes referred to as the trabecular meshwork or Schlemm’s canal.
5-FU: A medication that stops the healing process. Sometimes used around the new drainage hole created during surgery (the bleb) to stop it from healing or scarring over.
Glaucoma Suspect: A person may be considered a glaucoma suspect on the basis of high intraocular pressure, a suspicious appearance of the optic disc or visual field, a family history of glaucoma, or narrow angles between the iris and cornea.
Gonioscopy: In the gonioscopy test, a contact lens that contains a mirror is gently placed on the eye. The mirror lets the doctor look sideways into the eye to check whether the angle where the iris meets the cornea is open or closed. This helps the doctor decide whether open-angle or angle-closure glaucoma is present.
Intraocular Pressure (IOP): The internal pressure of the eye. Normal intraocular pressure usually ranges from 10-22 mm Hg, although people with relatively low pressures can still have glaucoma (see normal tension glaucoma).
Iris: The colored part of the eye that can expand or contract to allow just the right amount of light to enter the eye.
Laser Surgery: A type of surgery in which a tiny, powerful beam of light is used to solve problems in the eye. There are three common forms of laser surgery for glaucoma:
- Laser Peripheral Iridotomy – Creates a new drainage hole in the iris, allowing the iris to fall away from the outflow channel so fluid can drain out of the eye.
- Laser Trabeculoplasty – In this procedure, the laser is aimed toward the normal drainage channels of the eye, in an attempt to open those channels so fluid can leave the eye more efficiently.
- Laser Cyclophotocoagulation – This laser procedure is usually used in people who have severe glaucoma and are not responsive to standard glaucoma surgery. Laser energy is used to partially destroy the tissues that make the fluid within the eye.
Lens: Located behind the iris, helps light focus onto the retina.
Microsurgery: Surgery performed with a microscope in which and instrument is used to make a tiny, new opening in the sclera so that intraocular fluid can drain out of the inside of the eye.
Mm Hg: An abbreviation for “millimeters of mercury,” which is a scale for recording intraocular pressure.
Normal Tension Glaucoma: A rare form of glaucoma in which intraocular pressure stays within the normal range (10-22 mm Hg), but damage still occurs to the optic nerve and visual fields
Ophthalmoscopy: A test designed to examine the inside of the eye, especially the optic nerve. An instrument with a small light on the end is held up to the inside of the eye in a darkened room. This instrument lights up and magnifies the eye, and lets the doctor look at the shape and color of the optic nerve.
Optic Nerve: The nerve in the back of the eye that carries visual images to the brain.
Perimetry: (Also known as the visual field test.) A test that produces a map of the complete field of vision, designed to determine whether there is damage to any area of vision.
Peripheral Vision: The top, sides, and bottom areas of vision, which are usually the first areas of vision affected by glaucoma.
Pupil: The opening that regulates how much light enters the inner part of the eye.
Retina: The part of the eye that carries light and images to the brain through the optic nerve.
Sclera: The tough, white, protective, outer coat of the eye.
Tonometry: The use of a device to measure the pressure within the eye. There are three types of tonometry:
- Air Puff – This is the only type of tonometry that does not touch the surface of the eye. The patient sits upright at the instrument, and a warm puff of air is directed at the eye.
- Applanation – The patient’s eye is first treated with numbing drops and a stain called fluorescein. The tonometer is then placed gently on the cornea, and a very small amount of pressure is applied to the cornea. The patient may sit in front of the tonometer or a hand-held tonometer may be used.
- Schiotz – This type of tonometer was formerly used in the operating room or with people who are unable to sit upright (such as infants or small children). The patient is lying down or sitting back. After use of a numbing drop, the tonometer is placed gently on the front part of the eye. This type of tonometry is rarely used today.
Trabecular Meshwork: The formal name of the mesh-like drainage canals all around the iris.