The following are health and medical definitions of terms that appear in the Glaucoma article.
Abnormal: Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer).
Acute: Of abrupt onset, in reference to a disease. Acute often also connotes an illness that is of short duration, rapidly progressive, and in need of urgent care. See the entire definition of Acute
Acute angle-closure glaucoma: Increased pressure in the front chamber (anterior chamber) of the eye due to sudden (acute) blockage of the normal circulation of fluid within the eye. The block takes place at the angle of the anterior chamber formed by its junction of the cornea with the iris. This angle can be seen by simply looking at someone's eye from the side. Angle-closure glaucoma tends to affect people born with a narrow angle. People of Asian and Eskimo ancestry are at higher risk of developing it. Age and family history are risk factors. It occurs in older women more often than others. See the entire definition of Acute angle-closure glaucoma
Aging: The process of becoming older, a process that is genetically determined and environmentally modulated. See the entire definition of Aging
Agonist: A drug that binds to a receptor of a cell and triggers a response by the cell. An agonist often mimics the action of a naturally occurring substance. See the entire definition of Agonist
Anatomy: The study of form. Gross anatomy involves structures that can be seen with the naked eye. It is as opposed to microscopic anatomy (or histology) which involves structures seen under the microscope. Traditionally, both gross and microscopic anatomy have been studied in the first year of medical school in the U.S. The most celebrated textbook of anatomy in the English-speaking world is Gray's Anatomy, still a useful reference book. The word "anatomy" comes from the Greek ana- meaning up or through + tome meaning a cutting. Anatomy was once a "cutting up" because the structure of the body was originally learned through dissecting it, cutting it up. The abbreviation for anatomy is anat.
Anesthetic: A substance that causes lack of feeling or awareness. A local anesthetic causes loss of feeling in a part of the body. A general anesthetic puts the person to sleep.
Angle-closure glaucoma: This condition can be acute or chronic. It consists of increased pressure in the front chamber (anterior chamber) of the eye due to sudden (acute) or slowly progressive (chronic) blockage of the normal circulation of fluid within the eye. The block takes place at the angle of the anterior chamber formed by its junction of the cornea with the iris. This angle can be seen by simply looking at someone's eye from the side. Angle-closure glaucoma tends to affect people born with a narrow angle. People of Asian and Eskimo ancestry are at higher risk of developing it. Age and family history are risk factors. It occurs in older women more often than others. When the pupil of the eye is wide open (dilated), the iris is retracted and thickened and it block the canal of Schlemm, a key component of the drainage pathway for fluid within the eye. Blocking the drainage canal of Schlemm sends the pressure within the eye up. With acute angle-closure glaucoma, there is an abrupt increase in intraocular pressure (IOP) due to the buildup of aqueous (fluid) in the eye. The high pressure can damage the optic nerve (the nerve to the eye) and lead to blindness. The elevated pressure is best detected before the appearance of symptoms. That is why when the eyes are dilated in a doctor's office for a refraction, eye pressures are checked. When symptoms of acute angle glaucoma do develop, they include severe eye and facial pain, nausea and vomiting, decreased vision, blurred vision and seeing haloes around light. The eye in a far advanced case of angle closure glaucoma appears red with a steamy (clouded) cornea and a fixed (nonreactive) dilated pupil. Acute angle-closure glaucoma is an emergency because optic nerve damage and vision loss can occur within hours of the onset of the problem. Administering medications to lower the pressure within the eye is done first. In the past, a piece of the iris was then surgically removed in a procedure called an iridectomy to make a hole in the iris and create a channel (other than the canal of Sclemm) to permit the free flow of fluid. Today, a comparable procedure can be done by laser to burn a small hole in the iris to keep the intraocular pressure within normal limits. This condition can be chronic (progressing slowly or occurring persistently) or acute (occurring suddenly). Chronic angle-closure glaucoma, like the more common type of glaucoma (open-angle glaucoma), may cause vision damage without symptoms.
Antagonist: In biochemistry, an antagonist acts against and blocks an action. For example, insulin lowers the level of glucose (sugar) in the blood, whereas another hormone called glucagon raises it; therefore, insulin and glucagon are antagonists. See the entire definition of Antagonist
Anterior: The front, as opposed to the posterior. The anterior surface of the heart is toward the breast bone (the sternum). See the entire definition of Anterior
Aqueous humor: In medicine, humor refers to a fluid (or semifluid) substance. Thus, the aqueous humor is the fluid normally present in the front and rear chambers of the eye. It is a clear, watery fluid that flows between and nourishes the lens and the cornea; it is secreted by the ciliary processes. See the entire definition of Aqueous humor
Asthma: A common disorder in which chronic inflammation of the bronchial tubes (bronchi) makes them swell, narrowing the airways. Asthma involves only the bronchial tubes and does not affect the air sacs (alveoli) or the lung tissue (the parenchyma of the lung) itself. See the entire definition of Asthma
Asymptomatic: Without symptoms. For example, an asymptomatic infection is an infection with no symptoms.
Biopsy: The removal of a sample of tissue for purposes of diagnosis. (Many definitions of "biopsy" stipulate that the sample of tissue is removed for examination under a microscope. This may or may not be the case. The diagnosis may be achieved by other means such as by analysis of chromosomes or genes.) See the entire definition of Biopsy
Bleb: A bladder-like structure more than 5 mm in diameter with thin walls that may be full of fluid. Also called a bulla.
Blind:1. Unable to see. Without part or all of the sense of sight. 2. In a clinical trial, not to know the treatment given or received. The participant is not told whether they are in the experimental or control arm of the study. Also called masked.
Blindness: Loss of useful sight. Blindness can be temporary or permanent. Damage to any portion of the eye, the optic nerve, or the area of the brain responsible for vision can lead to blindness. There are numerous (actually, innumerable) causes of blindness. The current politically correct terms for blindness include visually handicapped and visually challenged.
Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It's measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called "hypertension".
Blurred vision: Lack of sharpness of vision with, as a result, the inability to see fine detail. Blurred vision can occur when a person who wears corrective lens is without them. Blurred vision can also be an important clue to eye disease.
Bradycardia: A slow heart rate, usually defined as less than 60 beats per minute. See the entire definition of Bradycardia
Brain: That part of the central nervous system that is located within the cranium (skull). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres."
Capillaries: Capillaries are the smallest of blood vessels. They serve to distribute oxygenated blood from arteries to the tissues of the body and to feed deoxygenated blood from the tissues back into the veins. The capillaries are thus a central component in the circulatory system, essentially between the arteries and the veins. When pink areas of skin are compressed, this causes blanching because blood is pressed out of the capillaries. The blood is the fluid in the body that contains, among other elements, the red blood cells (erythrocytes) that carry the oxygen and give the blood its red color.
Capillary: One of the tiny blood vessels that connect the arterioles (the smallest divisions of the arteries) and the venules (the smallest divisions of the veins). The capillaries form a fine network in many parts of the body. See the entire definition of Capillary
Capsule: Capsule has many meanings in medicine including the following:
In medicine, a membranous structure that envelops an organ, a joint, tumor, or any other part of the body. It is usually made up of dense collagen-containing connective tissue.
In pharmacy, a solid dosage form in which the drug is enclosed in a hard or soft soluble container, usually of a form of gelatin.
In microbiology, a coat around a microbe, such as a bacterium or fungus.
Central vision: Straight-ahead vision. Central vision is the work of the macula, a small area in the center of the retina that contains a rich collection of cones. (The retina is made up of two types of cells, the cones and the rods. Millions of cones are packed into the macula. The cones are nerve cells sensitive to light, fine detail, and color.) Central vision permits a person to read, drive, and perform other activities that require fine, sharp, straight-ahead vision. As opposed to peripheral vision.
Chin: Medically, the mentum. The lower portion of the face below the lower lip including the prominence of the lower jaw and the line of fusion of the two separate halves of the jawbone (mandible). This line of fusion (called the symphysis menti) encloses a triangular area at tip of the chin (termed the mental protuberance). On each side, below the second premolar tooth, is the mental foramen, an opening for the passage of blood vessels and a nerve that supply the chin.
Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time. See the entire definition of Chronic
Chronic disease: A disease that persists for a long time. A chronic disease is one lasting 3 months or more, by the definition of the U.S. National Center for Health Statistics. Chronic diseases generally cannot be prevented by vaccines or cured by medication, nor do they just disappear. Eighty-eight percent of Americans over 65 years of age have at least one chronic health condition (as of 1998). Health damaging behaviors - particularly tobacco use, lack of physical activity, and poor eating habits - are major contributors to the leading chronic diseases. See the entire definition of Chronic disease
Ciliary body: Part of the eye, the ciliary body is a thin vascular (blood vessel-filled) middle layer of the eye that is situated between the sclera (the white of the eye) and the retina (the nerve layer that lines the back of the eye, senses light, and creates impulses that travel through the optic nerve to the brain). See the entire definition of Ciliary body
Circulation: The movement of fluid in a regular or circuitous course. Although the noun "circulation" does not necessarily refer to the circulation of the blood, for all practical purposes today it does. Heart failure is an example of a problem with the circulation.
Congenital: Present at birth. A condition that is congenital is one that is present at birth. There are numerous uses of "congenital" in medicine. There are, for example, congenital abnormalities. (For more examples, see below.) See the entire definition of Congenital
Congestive heart failure: Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling (edema), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart. See the entire definition of Congestive heart failure
Conjunctiva: A thin clear moist membrane that coats the inner surfaces of the eyelids and the outer surface of the eye. See the entire definition of Conjunctiva
Conjunctival: Pertaining to the conjunctiva, the clear moist membrane that covers the inner surfaces of the eyelids and the front of eyeball.
Contrast: Short for "contrast media." Contrast media are X-ray dyes used to provide contrast, for example, between blood vessels and other tissue.
Cornea: The clear front window of the eye that transmits and focuses light into the eye. See the entire definition of Cornea
Corneal: Pertaining to the cornea, the clear front window of the eye that transmits and focuses light into the eye.
Cortisone: An adrenocorticoid hormone, a naturally occurring hormone made by and secreted by the adrenal cortex, the outer part (the cortex) of the adrenal gland. See the entire definition of Cortisone
Cupping:1. A cup-shaped depression, as in the head of the optic nerve in the eye. See the entire definition of Cupping
Cure:1. To heal, to make well, to restore to good health. Cures are easy to claim and, all too often, difficult to confirm. 2. A time without recurrence of a disease so that the risk of recurrence is small, as in the 5-year cure rate for malignant melanoma. 3. Particularly in the past, a course of treatment. For example, take a cure at a spa. See the entire definition of Cure
Diabetes: Refers to diabetes mellitus or, less often, to diabetes insipidus. Diabetes mellitus and diabetes insipidus share the name "diabetes" because they are both conditions characterized by excessive urination (polyuria). See the entire definition of Diabetes
Diagnosis:1 The nature of a disease; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies. 3 The identification of any problem. The diagnosis was a plugged IV. See the entire definition of Diagnosis
Dilate: To stretch or enlarge. It comes from the Latin verb "dilatare" meaning "to enlarge or expand."
Disc: Shortened terminology for an intervertebral disc, a disk-shaped piece of specialized tissue that separates the bones of the spinal column. See the entire definition of Disc
Drain: A device for removing fluid from a cavity or wound. A drain is typically a tube or wick. As a verb, to allow fluid to be released from a confined area.
Edema: The swelling of soft tissues as a result of excess water accumulation. See the entire definition of Edema
Emphysema: 1) A lung condition featuring an abnormal accumulation of air in the lung's many tiny air sacs, a tissue called alveoli. As air continues to collect in these sacs, they become enlarged, and may break, or be damaged and form scar tissue. Emphysema is strongly associated with smoking cigarettes, a practice that causes lung irritation. It can also be associated with or worsened by repeated infection of the lungs, such as is seen in chronic bronchitis. The best response to the early warning signs of emphysema is prevention: stop smoking and get immediate treatment for incipient lung infections. Curing established emphysema is not yet possible. Because patients don't have an adequate amount of space in the lungs to breathe, they gasp for breath, and may not be able to obtain enough oxygen. Those with severe emphysema usually end up using an oxygen machine to breathe. In some cases, medication may be helpful to ease symptoms or to treat infection in already-damaged lungs. See the entire definition of Emphysema
Epinephrine: A substance produced by the medulla (inside) of the adrenal gland. The name epinephrine was coined in 1898 by the American pharmacologist and physiologic chemist (biochemist) John Jacob Abel who isolated it from the adrenal gland which is located above (epi-) the kidney ("nephros" in Greek). (Abel also crystallized insulin). Technically speaking, epinephrine is a sympathomimetic catecholamine. It causes quickening of the heart beat, strengthens the force of the heart's contraction, opens up the airways (bronchioles) in the lungs and has numerous other effects. The secretion of epinephrine by the adrenal is part of the fight-or-flight reaction. Adrenaline is a synonym of epinephrine and is the official name in the British Pharmacopoeia.
Family history: The family structure and relationships within the family, including information about diseases in family members. See the entire definition of Family history
Farsightedness: Medically termed hyperopia; the ability to see distant objects more clearly than close objects. See the entire definition of Farsightedness
Fatigue: A condition characterized by a lessened capacity for work and reduced efficiency of accomplishment, usually accompanied by a feeling of weariness and tiredness. Fatigue can be acute and come on suddenly or chronic and persist. See the entire definition of Fatigue
FDA: The Food and Drug Administration, an agency within the U.S. Public Health Service, which is a part of the Department of Health and Human Services. See the entire definition of FDA
Gland:1. A group of cells that secrete a substance for use in the body. For example, the thyroid gland. 2. A group of cells that removes materials from the circulation. For example, a lymph gland.
Glaucoma: A common eye condition in which the fluid pressure inside the eyes rises because of slowed fluid drainage from the eye. If untreated, it may damage the optic nerve and other parts of the eye, causing the loss of vision or even blindness. See the entire definition of Glaucoma
Headache: A pain in the head with the pain being above the eyes or the ears, behind the head (occipital), or in the back of the upper neck. Headache, like chest pain or back ache, has many causes. See the entire definition of Headache
Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest. See the entire definition of Heart
Heart failure: Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling (edema), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart. See the entire definition of Heart failure
Heart rate: The number of heart beats per unit time, usually per minute. The heart rate is based on the number of contractions of the ventricles (the lower chambers of the heart). The heart rate may be too fast (tachycardia) or too slow (bradycardia). The pulse is bulge of an artery from the wave of blood coursing through the blood vessel as a result of the heart beat. The pulse is often taken at the wrist to estimate the heart rate.
Humor: In medicine, humor refers to a fluid (or semifluid) substance. Thus, the aqueous humor is the fluid normally present in the front and rear chambers of the eye. The humors ran through an ancient theory that held that health came from balance between the bodily liquids. These liquids were termed humors. Disease arose when there was imbalance between these humors. See the entire definition of Humor
Hyperopia: Farsightedness; the ability to see distant objects more clearly than close objects. See the entire definition of Hyperopia
Impotence: A common problem among men characterized by the consistent inability to sustain an erection sufficient for sexual intercourse or the inability to achieve ejaculation, or both. Impotence can vary. It can involve a total inability to achieve an erection or ejaculation, an inconsistent ability to do so, or a tendency to sustain only very brief erections. See the entire definition of Impotence
Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person. See the entire definition of Infection
Inflammation: A basic way in which the body reacts to infection, irritation or other injury, the key feature being redness, warmth, swelling and pain. Inflammation is now recognized as a type of nonspecific immune response. See the entire definition of Inflammation
Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury. The injury may be accidental or deliberate, as with a needlestick injury. The term "injury" may be synonymous (depending on the context) with a wound or with trauma.
Intraocular: In the eye. The intraocular pressure is the pressure within the eye.
Intraocular pressure: The pressure created by the continual renewal of fluids within the eye. The intraocular pressure is increased in glaucoma. See the entire definition of Intraocular pressure
Iodide: The chemical form to which iodine in the diet is reduced before it is absorbed through the intestinal wall into the bloodstream and carried through the blood to the thyroid gland.
Iris: The iris is the circular, colored curtain of the eye. Its opening forms the pupil. The iris helps regulate the amount of light that enters the eye. See the entire definition of Iris
Iritis: Inflammation of the iris. The iris is the circular, colored curtain in the front of the visible of the eye. (The opening of the iris forms the pupil.)
Kidney: One of a pair of organs located in the right and left side of the abdomen which clear "poisons" from the blood, regulate acid concentration and maintain water balance in the body by excreting urine. The kidneys are part of the urinary tract. The urine then passes through connecting tubes called "ureters" into the bladder. The bladder stores the urine until it is released during urination.
Laser: A powerful beam of light that can produce intense heat when focused at close range. Lasers are used in medicine in microsurgery, cauterization, for diagnostic purposes, etc. For example, lasers are employed in microsurgery to cut tissue and remove tissue. See the entire definition of Laser
Lens: The transparent structure inside the eye that focuses light rays onto the retina (the nerve layer that lines the back of the eye, senses light and creates impulses that go through the optic nerve to the brain). The lens was named after the lentil bean because it resembled it in shape and size. See the entire definition of Lens
Liver: An organ in the upper abdomen that aids in digestion and removes waste products and worn-out cells from the blood. The liver is the largest solid organ in the body. The liver weighs about three and a half pounds (1.6 kilograms). It measures about 8 inches (20 cm) horizontally (across) and 6.5 inches (17 cm) vertically (down) and is 4.5 inches (12 cm) thick.
Low blood pressure: Any blood pressure that is below the normal expected for an individual in a given environment. Low blood pressure is also referred to as hypotension. See the entire definition of Low blood pressure
Lungs: The lungs are a pair of breathing organs located with the chest which remove carbon dioxide from and bring oxygen to the blood. There is a right and left lung.
Marijuana: A very common street and recreational drug that comes from the marijuana plant. See the entire definition of Marijuana
Membrane: A very thin layer of tissue that covers a surface.
Microscopic: So small it cannot be seen without the aid of microscope. As opposed to macroscopic (large enough to be seen with naked eye). A tiny tumor is microscopic while a big tumor is macroscopic.
Mouth:1. The upper opening of the digestive tract, beginning with the lips and containing the teeth, gums, and tongue. Foodstuffs are broken down mechanically in the mouth by chewing and saliva is added as a lubricant. Saliva contains amylase, an enzyme that digests starch. 2. Any opening or aperture in the body. The mouth in both senses of the word is also called the os, the Latin word for an opening, or mouth. The o in os is pronounced as in hope. The genitive form of os is oris from which comes the word oral.
Myopia: Nearsightedness, the ability to see close objects more clearly than distant objects. See the entire definition of Myopia
Nausea:Nausea, is the urge to vomit. It can be brought by many causes including, systemic illnesses, such as influenza, medications, pain, and inner ear disease. When nausea and/or vomiting are persistent, or when they are accompanied by other severe symptoms such as abdominal pain, jaundice, fever, or bleeding, a physician should be consulted.
Nearsightedness: The ability to see near objects more clearly than distant objects. Also called myopia . See the entire definition of Nearsightedness
Nerve: A bundle of fibers that uses chemical and electrical signals to transmit sensory and motor information from one body part to another. See: Nervous system.
Normal range: By convention, the normal range for whatever (a particular test, condition, symptom, behavior, etc.) is set to cover ninety-five percent (95%) of all values from the general population. Five percent (5%) of results consequently fall outside the normal range. Values that prove normal can therefore sometimes be outside the normal range. See the entire definition of Normal range
Onset: In medicine, the first appearance of the signs or symptoms of an illness as, for example, the onset of rheumatoid arthritis. There is always an onset to a disease but never to the return to good health. The default setting is good health. See the entire definition of Onset
Open-angle glaucoma: Glaucoma in which the aqueous (fluid) that flows through the pupil into the anterior (front) chamber of the eye cannot get through a filtration system called the trabecular meshwork into the drainage canals, causing pressure to build up within the eye which can damage the optic nerve and impair vision. See the entire definition of Open-angle glaucoma
Operation: Although there are many meanings to the word "operation", in medicine it refers to a surgical procedure. See the entire definition of Operation
Ophthalmologist: An eye doctor. A physician practicing ophthalmology. An ophthalmologist is an M.D.
Ophthalmology: The art and science of eye medicine.
Ophthalmoscopy: Examination of the interior of the eye, including the lens, retina and optic nerve, by indirect or direct ophthalmoscopy. See the entire definition of Ophthalmoscopy
Optic: Having to do with vision.
Optic disc: The circular area in the back of the inside of the eye where the optic nerve connects to the retina. Also called the optic nerve head.
Optic nerve: The optic nerve connects the eye to the brain. The optic nerve carries the impulses formed by the retina, the nerve layer that lines the back of the eye and senses light and creates impulses. These impulses are dispatched through the optic nerve to the brain, which interprets them as images. Using an ophthalmoscope, the head of the optic nerve can be easily seen. It can be viewed as the only visible part of the brain (or extension of it). See the entire definition of Optic nerve
Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia. Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors. See the entire definition of Pain
Peripheral: Situated away from the center, as opposed to centrally located. See the entire definition of Peripheral
Peripheral vision: Side vision. The ability to see objects and movement outside of the direct line of vision. Peripheral vision is the work of the rods, nerve cells located largely outside the macula (the center) of the retina. The rods are also responsible for night vision and low-light vision but are insensitive to color. As opposed to central vision.
Periphery:1. The outside or surface of a structure; the portion outside the central region. See the entire definition of Periphery
Pigment: A substance that gives color to tissue. Pigments are responsible for the color of skin, eyes, and hair.
Potassium: The major positive ion (cation) found inside of cells. The chemical notation for potassium is K+. See the entire definition of Potassium
Predispose: To make more likely or render susceptible. Smoking predisposes to a number of diseases, including esophageal cancer.
Progressive: Increasing in scope or severity. Advancing. Going forward. In medicine, a disease that is progressive is going from bad to worse.
Prostaglandin: One of a number of hormone-like substances that participate in a wide range of body functions such as the contraction and relaxation of smooth muscle, the dilation and constriction of blood vessels, control of blood pressure, and modulation of inflammation. Prostaglandins are derived from a chemical called arachidonic acid.
Pulmonary: Having to do with the lungs. (The word comes from the Latin pulmo for lung).
Pupil: The opening of the iris. The pupil may appear to open (dilate) and close (constrict) but it is really the iris that is the prime mover; the pupil is merely the absence of iris. The pupil determines how much light is let into the eye. Both pupils are usually of equal size. If they are not, that is termed anisocoria (from "a-", not + "iso", equal + "kore", pupil = not equal pupils). See the entire definition of Pupil
Reservoir:1. A place where something such as water is kept in reserve. 2. The part of a device in which something is kept in reserve or stored, as an Ommaya reservoir. 3. For an infectious agent, an animal, person, plant, soil, or other substance in which the agent normally abides. See: Reservoir of infection. From the French reservoir, from reserver meaning to reserve.
Retina: The retina is the nerve layer that lines the back of the eye, senses light, and creates impulses that travel through the optic nerve to the brain. There is a small area, called the macula, in the retina that contains special light-sensitive cells. The macula allows us to see fine details clearly. See the entire definition of Retina
Retinal: Pertaining to the retina, the extraordinary layer of neurons (nerve cells) that line the back of the eye, which can sense light and create impulses capable of voyaging through the optic nerve to the brain where the impulses are recognized as an image. See the entire definition of Retinal
Retinal detachment: A separation of the retina from its connection at the back of the eye. The separation usually results from a tear (that is, a rent or rip, not a tear drop) in the retina. The tear often occurs when the vitreous gel pulls loose or separates from its attachment to the retina, usually in the outside edges of the eye. The vitreous is a clear gel that fills most of the inside of the eye between the retina and the lens. If the retina is weak when the vitreous gel pulls loose, the retina will tear. This rip is sometimes accompanied by bleeding, or hemorrhage, if a blood vessel is also torn. See the entire definition of Retinal detachment
Risk factor: Something that increases a person's chances of developing a disease.
Sclera: The tough white outer coat over the eyeball that covers approximately the posterior five-sixths of its surface. The sclera is continuous in the front of the eye with the cornea and in the back of the eye with the external sheath of the optic nerve. See the entire definition of Sclera
Shunt: 1) To move a body fluid, such as cerebrospinal fluid, from one place to another. 2) A catheter (tube) that carries cerebrospinal fluid from a ventricle in the brain to another area of the body. A shunt may be placed to relieve pressure from hydrocephalus, for example.
Surgeon: A physician who treats disease, injury, or deformity by operative or manual methods. A medical doctor specialized in the removal of organs, masses and tumors and in doing other procedures using a knife (scalpel). The definition of a "surgeon" has begun to blur in recent years as surgeons have begun to minimize the cutting, employ new technologies that are "minimally invasive," use scopes, etc. See the entire definition of Surgeon
Surgery: The word "surgery" has multiple meanings. It is the branch of medicine concerned with diseases and conditions which require or are amenable to operative procedures. Surgery is the work done by a surgeon. By analogy, the work of an editor wielding his pen as a scalpel is s form of surgery. A surgery in England (and some other countries) is a physician's or dentist's office. See the entire definition of Surgery
Symptom: Any subjective evidence of disease. Anxiety, lower back pain, and fatigue are all symptoms. They are sensations only the patient can perceive. In contrast, a sign is objective evidence of disease. A bloody nose is a sign. It is evident to the patient, doctor, nurse and other observers.
Systemic: Affecting the entire body. A systemic disease such as diabetes can affect the whole body. Systemic chemotherapy employs drugs that travel through the bloodstream and reach and affect cells all over the body.
Tension: 1) The pressure within a vessel, such as blood pressure: the pressure within the blood vessels. For example, elevated blood pressure is referred to as hypertension. 2) Stress, especially stress that is translated into clenched scalp muscles and bottled-up emotions or anxiety. This is the type of tension blamed for tension headaches.
Therapeutic: Relating to therapeutics, that part of medicine concerned specifically with the treatment of disease. The therapeutic dose of a drug is the amount needed to treat a disease. See the entire definition of Therapeutic
Tonometry: A standard eye test that determines the fluid pressure inside the eye. Increased pressure is a possible sign of glaucoma, a common and potentially very serious eye problem if not detected and treated promptly. It is recommended that adults over age 40 have tonometry for glaucoma every 3 to 5 years by having their eye pressures measured. See the entire definition of Tonometry
Topical: Pertaining to a particular surface area. A topical agent is applied to a certain area of the skin and is intended to affect only the area to which it is applied. Whether its effects are indeed limited to that area depends upon whether the agent stays where it is put or is absorbed into the blood stream.
Trauma: Any injury, whether physically or emotionally inflicted. "Trauma" has both a medical and a psychiatric definition. Medically, "trauma" refers to a serious or critical bodily injury, wound, or shock. This definition is often associated with trauma medicine practiced in emergency rooms and represents a popular view of the term. In psychiatry, "trauma" has assumed a different meaning and refers to an experience that is emotionally painful, distressful, or shocking, which often results in lasting mental and physical effects. See the entire definition of Trauma
Tubes: The "tubes" are medically known as the Fallopian tubes. There are two Fallopian tubes, one on each side, which transport the egg from the ovary to the uterus (the womb). The Fallopian tubes have small hair-like projections called cilia on the cells of the lining. See the entire definition of Tubes
Vein: A blood vessel that carries blood low in oxygen content from the body back to the heart. The deoxygenated form of hemoglobin (deoxyhemoglobin) in venous blood makes it appear dark. Veins are part of the afferent wing of the circulatory system which returns blood to the heart. See the entire definition of Vein
Visual acuity: The clarity or clearness of the vision, a measure of how well a person sees. The ability to distinguish details and shapes of objects; also called central vision. See the entire definition of Visual acuity
Visual field: The entire area that can be seen when the eye is directed forward, including that which is seen with peripheral vision. See the entire definition of Visual field
Headaches can be divided into two categories: primary headaches and secondary headaches. Migraine headaches, tension headaches, and cluster headaches are considered primary headaches. Secondary headaches are caused by disease. Headache symptoms vary with the headache type. Over-the-counter pain relievers provide short-term relief for most headaches.
Diabetes mellitus is a chronic condition characterized by high levels of sugar (glucose) in the blood. The two types of diabetes are referred to as type 1 (insulin dependent) and type 2 (non-insulin dependent). Symptoms of diabetes include increased urine output, thirst, hunger, and fatigue. Treatment of diabetes depends on the type.
Sarcoidosis, a disease resulting from chronic inflammation, causes small lumps (granulomas) to develop in a great range of body tissues and can appear in almost any body organ. However, sarcoidosis most often starts in the lungs or lymph nodes.
Retinal detachment is the separation of the retina from its attachments to the underlying eye tissue. Symptoms of retinal detachment include flashing lights and floaters. Highly nearsighted young adults and those who've had cataract surgery are at higher risk for retinal detachment.
Marfan syndrome is hereditary condition affecting connective tissue. A person with Marfan syndrome may exhibit the following symptoms and characteristics: dislocation of one or both lenses of the eye; a protruding or indented breastbone; scoliosis; flat feet; aortic dilatation; dural ectasia; stretch marks; hernia; and lung collapse. Though there is no cure for Marfan syndrome, there are treatments that can minimize and sometimes prevent some complications.
Optic neuritis is inflammation of the optic nerve, the structure that connects the eye to the brain. The precise cause of optic neuritis is unknown, but it is thought to be a type of autoimmune disorder. Optic neuritis most commonly develops due to an autoimmune disorder that may be triggered by a viral infection.
A cataract is an eye disease that causes the eye's lens to become cloudy and opaque with decreased vision. Causes of cataracts include diabetes, hypothyroidism, certain genetic illnesses, hyperparathyroidism, atopic dermatitis, and certain medications. Symptoms and signs include a decrease in vision and a whitish color to the affected eye. Treatment depends upon the patient's specific visual needs and may involve cataract surgery.
Many common eye disorders resolve without treatment and some may be managed with over-the-counter (OTC) products. It's important to visit a physician or ophthalmologist is the problem involves the eyeball itself or the condition hasn't improved after 72 hours of use of an eye-care OTC product.
Birthmarks and other abnormal skin pigmentation is caused by the body's inability to produce enough melanin. Abnormal skin pigmentation can cause conditions such as vitiligo, pigmentation loss, melasma, albinism, port wine stains, macular stains and hemangioma.
Uveitis is inflammation of the eye. Symptoms include blurred vision, eye pain, eye redness, and floating spots before the eyes. Treatment may involve prescription eyedrops, antibiotics, and wearing dark glasses.
The most common cause of a black eye is due to an injury to the face or head. Most black eye injuries are minor and heal on their own, however, some may lead to significant injury. In addition to trauma to the face, cosmetic surgery can cause a black eye(s) as a side effect. People should be aware of the situations in which medical care should be sought immediately for a black eye.
Blindness is the state of being sightless. Causes of blindness include macular degeneration, stroke, cataract, glaucoma, infection and trauma. Symptoms and signs may include eye pain, eye discharge, or the cornea or pupil turning white. Treatment of blindness depends upon the cause of the blindness.
Iritis is inflammation of the iris, the colored portion of the eye. Symptoms include a red, painful eye, blurry vision, and light sensitivity. Treatment usually involves cortisone eyedrops.
Becoming infected with chickenpox during pregnancy could cause birth defects in your unborn child. Likewise, shingles could also cause problems for your unborn child. If you are pregnant and haven't had chickenpox, avoid exposure to infected people. Zostavax, the shingles vaccine, can reduce the incidence of shingles by half. Women should wait at least three months after receiving the vaccine before trying to get pregnant.
Diabetes and eye problems are generally caused by high blood sugar levels over an extended period of time. Types of eye problems in a person with diabetes include glaucoma, cataracts, and retinopathy. Examples of symptoms include blurred vision, headaches, eye aches, pain, halos around lights, loss of vision, watering eyes. Treatment for eye problems in people with diabetes depend on the type of eye problem. Prevention of eye problems include reducing blood pressure, cholesterol levels, quitting smoking, and maintaining proper blood glucose levels.
eye. Read about symptoms, signs, diagnosis, treatment, and prognosis.
Coats' disease is a rare eye condition that typically progresses to vision loss or blindness in one eye. Gradual vision loss is usually the first symptom, followed by a cloudy white or yellow pupil due to the presence of a cataract. Treatment focuses on limiting the blood vessel progression and may involve cryotherapy or laser photocoagulation.
Klippel-Trènaunay-Weber (KTW) syndrome is a condition characterized by port-wine stains or birthmark malformations in the skin, soft tissue and bony growths (generally involving a limb), and vascular anomalies (varicose veins). The cause of Klippel-Trènaunay-Weber syndrome is not known, however, recently, there have been some cases that run in families. There is no significant treatment for Klippel-Trènaunay-Weber syndrome.
Disease prevention in men includes routine screening tests that are part of basic prevention medicine. Take an active role in your own health care and discuss screening tests with your doctor early in life. Age of screening and timing of screening depends upon the condition being assessed.
Disease prevention in women includes screening tests that are a basic part of prevention medicine. All screening tests
are commonly available through your general doctor. Some specialized tests may be available elsewhere.
A visual field test is a method of measuring an individual's entire scope of vision, that is their central and peripheral (side) vision. Visual field testing actually maps the visual fields of each eye individually. The visual field test is a subjective examination, requiring the patient to understand the testing instructions, fully cooperate, and complete the entire test in order to provide useful information.
What is a visual field test used for?
Visual field testing is most frequently used to detect any signs of glaucoma damage to the optic nerve. In addition, visual field tests are useful for detection of central or peripheral retinal disease, eyelid conditions such as ptosis or drooping, optic nerve disease, and diseases affecting the visual pathways within the brain. The visual pathways carry information from the eye to the visual or occipital cortex in the brain, where this information is proces...
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