Macular Degeneration Glossary of Medical Terms

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 ).
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Acetate: A molecular ion derived from acetic acid . The formula of acetate is CH3COO-.
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Age-related macular degeneration : An eye disease with its onset usually after age 60 that progressively destroys the macula , the central portion of the retina , impairing central vision . Age-related macular degeneration (AMD) rarely causes blindness because only the center of vision is affected. However, injury to the macula in the center of the retina can impair the ability to see straight ahead clearly and sometimes make it difficult to read, drive, or perform other daily activities that require fine central vision.
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Aging: The process of becoming older, a process that is genetically determined and environmentally modulated.
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Amsler grid: While conducting an eye examination, the eye care professional may ask the patient to look at an Amsler grid. This grid is a pattern that resembles a checkerboard. The patient covers one eye and stares at a black dot in the center of the grid. While staring at the dot, the patient may notice that the straight lines in the pattern appear wavy.

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Angiogram: An x-ray of blood vessels which can be seen because the patient receives an injection of dye to outline the vessels on the x-ray.
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Angiography: A procedure performed to view blood vessels after injecting them with a radioopaque dye that outlines them on x-ray . This technique can be usefully used to look at arteries in many areas of the body, including the brain, neck ( carotids ), heart , aorta , chest , pulmonary circuit, kidneys , gastrointestinal tract, and limbs .
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Antibody: An immunoglobulin, a specialized immune protein , produced because of the introduction of an antigen into the body, and which possesses the remarkable ability to combine with the very antigen that triggered its production.
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Antioxidant: Any substance that reduces oxidative damage (damage due to oxygen ) such as that caused by free radicals. Free radicals are highly reactive chemicals that attack molecules by capturing electrons and thus modifying chemical structures.
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Arm: 1. In popular usage, the appendage that extends from the shoulder to the hand. However, the medical definition refers to the upper extremity extending from the shoulder only to the elbow, excluding the forearm, which extends from the elbow to the wrist. The arm contains one bone: the humerus. 2. In a randomized clinical trial, any of the treatment groups. Most randomized trials have two "arms," but some have three "arms," or even more.
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ARMD: Age-related macular degeneration (which may also be abbreviated as AMD).
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Atrophy: Wasting away or diminution. Muscle atrophy is wasting of muscle, decrease in muscle mass.
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Avastin: The first drug in a new class designed to treat cancer by compromising its blood supply. Avastin (bevacizumab) is believed to prevent angiogenesis , the formation of new blood vessels that supply the tumor with blood, oxygen and other nutrients and allow the tumor to grow and metastasize to other sites in the body. Additionally, Avastin may interfere with tumor growth by causing blood vessels to shrink away from a tumor.
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Bevacizumab: Generic name for a monoclonal antibody anticancer drug. See: Avastin .
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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.
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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.
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Blood: The familiar red fluid in the body that contains white and red blood cells , platelets , proteins , and other elements. The blood is transported throughout the body by the circulatory system . Blood functions in two directions: arterial and venous. Arterial blood is the means by which oxygen and nutrients are transported to tissues while venous blood is the means by which carbon dioxide and metabolic by-products are transported to the lungs and kidneys, respectively, for removal from the body.
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Cancer: An abnormal growth of cells which tend to proliferate in an uncontrolled way and, in some cases, to metastasize (spread).
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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.
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Choroid: In the eye, a thin vascular layer between the sclera and the retina. The choroid supplies blood to the retina and conducts arteries and nerves to other structures in the eye.
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Clinical trial: See: Clinical trials . See also: Inconclusive clinical trial ; Negative clinical trial ; Non-inferior clinical trial ; Positive clinical trial .
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Clinical trials: Trials to evaluate the effectiveness and safety of medications or medical devices by monitoring their effects on large groups of people.
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Colon: The part of the large intestine that runs from the cecum to the rectum as a long hollow tube that serves to remove water from digested food and let the remaining material, solid waste called stool , move through it to the rectum and leave the body through the anus . .
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Condition: The term "condition" has a number of biomedical meanings including the following:

1. An unhealthy state, such as in "this is a progressive condition."
2. A state of fitness, such as "getting into condition."
3. Something that is essential to the occurrence of something else; essentially a "precondition."
4. As a verb: to cause a change in something so that a response that was previously associated with a certain stimulus becomes associated with another stimulus; to condition a person, as in behavioral conditioning.

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Contrast: Short for "contrast media." Contrast media are X-ray dyes used to provide contrast, for example, between blood vessels and other tissue.
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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.
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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.
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DOTS: Stands for Directly Observed Treatment, Short-course.
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Drusen: Tiny yellow or white deposits in the retina of the eye or on the optic nerve head.
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Ear: The hearing organ. There are three sections of the ear, according to the anatomy textbooks. They are the outer ear (the part we see along the sides of our head behind the temples), the middle ear, and the inner ear. But in terms of function, the ear has four parts: those three and the brain. Hearing thus involves all parts of the ear as well as the auditory cortex of the brain. The external ear helps concentrate the vibrations of air on the ear drum and make it vibrate. These vibrations are transmitted by a chain of little bones in the middle ear to the inner ear. There they stimulate the fibers of the auditory nerve to transmit impulses to the brain.
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Emergency department: The department of a hospital responsible for the provision of medical and surgical care to patients arriving at the hospital in need of immediate care. Emergency department personnel may also respond to certain situations within the hospital such cardiac arrests.
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Endothelial: Relating to the endothelium , the layer of flat cells lining the closed spaces of the body such as the inside of blood vessels, lymphatic vessels, the heart , and body cavities .
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Epithelium: The outside layer of cells that covers all the free, open surfaces of the body including the skin, and mucous membranes that communicate with the outside of the body. By contrast the endothelium is the layer of cells lining the closed internal spaces of the body such as the blood vessels and lymphatic vessels (that convey the lymph, a milky fluid).
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Family history: The family structure and relationships within the family, including information about diseases in family members.
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Fat: 1 Along with proteins and carbohydrates, one of the three nutrients used as energy sources by the body. The energy produced by fats is 9 calories per gram. Proteins and carbohydrates each provide 4 calories per gram. 2 Total fat; the sum of saturated, monounsaturated and polyunsaturated fats. Intake of monounsaturated and polyunsaturated fats can help reduce blood cholesterol when substituted for saturated fats in the diet. 3 A slang term for obese or adipose. 4 In chemistry, a compound formed from chemicals called fatty acids. These fats are greasy, solid materials found in animal tissues and in some plants. Fats are the major component of the flabby material of a body, commonly known as blubber.
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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.
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Fluorescein angiography: A test to examine blood vessels in the retina, choroid, and iris of the eye. A special dye is injected into a vein in the arm and pictures are taken as the dye passes through the blood vessels in the eye.
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Food and Drug Administration: The FDA, an agency within the U.S. Public Health Service, which is a part of the Department of Health and Human Services.
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Genetic: Having to do with genes and genetic information.
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Hemorrhagic: Pertaining to bleeding or the abnormal flow of blood.
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Hospital: It may seem unnecessary to define a "hospital" since everyone knows the nature of a hospital. A hospital began as a charitable institution for the needy, aged, infirm, or young.
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In vivo: In the living organism, as opposed to in vitro (in the laboratory).
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Indicate: In medicine, to make a treatment or procedure advisable because of a particular condition or circumstance. For example, certain medications are indicated for the treatment of hypertension during pregnancy while others are contraindicated .
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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 .
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Intraocular: In the eye. The intraocular pressure is the pressure within the eye.
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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.
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Legal blindness: The criteria used to determine eligibility for government disability benefits and which do not necessarily indicate a person's ability to function.
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Macula: A macula is a small spot. A macula on the skin is a small flat spot while the macula in the eye is a small spot where vision is keenest in the retina.

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Macular: Pertaining to the macula. A macula is a small spot. A macula on the skin is a small flat spot while the macula in the eye is a small spot where vision is keenest in the retina .

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Macular degeneration : A disease that progressively destroys the macula , the central portion of the retina , impairing central vision . Macular degeneration rarely causes blindness because only the center of vision is affected. However, injury to the macula in the center of the retina can impair the ability to see straight ahead clearly and sometimes make it difficult to read, drive, or perform other daily activities that require fine central vision.
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Maculopathy: Any pathologic condition or disease of the macula, the small spot in the retina where vision is keenest. Also called macular retinopathy.

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Membrane: A very thin layer of tissue that covers a surface.
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Obesity: The state of being well above one's normal weight.
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Occult: Hidden.
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Ophthalmologist: An eye doctor. A physician practicing ophthalmology. An ophthalmologist is an M.D.
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Ophthalmology: The art and science of eye medicine.
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Ophthalmoscope: A lighted instrument, one of the most important tools of the physician, used to examine the interior of the eye , including the lens , retina and optic nerve .
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Oxygen: A colorless, odorless and tasteless gas that makes up about 20% of the air we breathe (and at least half the weight of the entire solid crust of the earth) and which combines with most of the other elements to form oxides. Oxygen is essential to human, animal and plant life.
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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.
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Peripheral: Situated away from the center, as opposed to centrally located.
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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.
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Periphery: 1. The outside or surface of a structure; the portion outside the central region.
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Pharmacy: A location where prescription drugs are sold. A pharmacy is, by law, constantly supervised by a licensed pharmacist.
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Photodynamic therapy: A form of cancer treatment using an photosensitizing agent administered intravenously which concentrates selectively in tumor cells, followed by exposure of the tumor tissue to a special red laser light, in order to destroy as much of the tumor as possible.
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Pigment: A substance that gives color to tissue. Pigments are responsible for the color of skin, eyes, and hair.
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Pons: A specific section of the brain formed by the rounded prominence on the front surface of the brainstem. (The brainstem is the lowest part of the brain that merges with the spinal cord; it consists of a structure called the medulla oblongata, the midbrain and the pons.) Cranial nerves V, VI, VII and VIII take origin at the border of the pons.
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Posterior: The back or behind, as opposed to the anterior.
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Public health: The approach to medicine that is concerned with the health of the community as a whole. Public health is community health. It has been said that: "Health care is vital to all of us some of the time, but public health is vital to all of us all of the time."
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Quality of life: An important consideration in medical care, quality of life refers to the patient's ability to enjoy normal life activities. Some medical treatments can seriously impair quality of life without providing appreciable benefit, while others greatly enhance quality of life.
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Rectum: The last 6 to 8 inches of the large intestine. The rectum stores solid waste until it leaves the body through the anus. The word rectum comes from the Latin rectus meaning straight (which the human rectum is not).
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Rest: 1. Repose. Relaxation.
2. A fragment of embryonic tissue that has been retained after the period of embryonic development. Also called an embryonic rest.
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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.
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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.
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Retinal disease: In medicine, called retinopathy. See: Retinopathy .
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Retinal pigment epithelium: The pigment cell layer that nourishes the retinal cells.
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Senile: 1. Pertaining to old age. 2. Pertaining to the physical decline associated with old age. 3. Pertaining to the mental decline once associated with old age but now known to be due to dementia , such as Alzheimer's disease or cerebral atherosclerosis . "The road to senility is paved with plaques." (Paul F. Wehrle, MD [1921-2004] pediatrician and vaccine researcher)
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Sensitivity: 1. In psychology, the quality of being sensitive. As, for example, sensitivity training, training in small groups to develop a sensitive awareness and understanding of oneself and of ones relationships with others. 2. In disease epidemiology, the ability of a system to detect epidemics and other changes in disease occurrence. 3. In screening for a disease, the proportion of persons with the disease who are correctly identified by a screening test. 4. In the definition of a disease, the proportion of persons with the disease who are correctly identified by defined criteria.
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Sign: Any objective evidence of disease. Gross blood in the stool is a sign of disease. It can be recognized by the patient, doctor, nurse, or others. In contrast, a symptom is, by its nature, subjective. Abdominal pain is a symptom. It is something only the patient can know.
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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.
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Therapy: The treatment of disease .
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Tomography: The process for generating a tomogram , a two-dimensional image of a slice or section through a three-dimensional object. Tomography achieves this remarkable result by simply moving an x-ray source in one direction as the x-ray film is moved in the opposite direction during the exposure to sharpen structures in the focal plane, while structures in other planes appear blurred. The tomogram is the picture; the tomograph is the apparatus; and tomography is the process.
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Vascular: Relating to the blood vessels of the body. The blood vessels of the body, as a group, are referred to as the vascular system.
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VEGF: Vascular endothelial growth factor, a substance made by cells that stimulates the formation of new blood vessels, a process called angiogenesis. VEGF also acts as a mitogen for vascular endothelial (vessel lining) cells, stimulating these cells to divide and multiply.
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Vessel: A tube in the body that carries fluids: blood vessels or lymph vessels.
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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.
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Vitamin C: An essential nutrient found mainly in fruits and vegetables. The body requires vitamin C to form and maintain bones, blood vessels, and skin.
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Vitamin E: Alpha-tocopherol, an antioxidant vitamin which binds oxygen free radicals that can cause tissue damage. Deficiency of vitamin E can lead to anemia . Vitamin E may play a possible role in preventing heart disease and cancer of the lung and prostate .
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Vitamins: The word "vitamin" was coined in 1911 by the Warsaw-born biochemist Casimir Funk (1884-1967). At the Lister Institute in London, Funk isolated a substance that prevented nerve inflammation (neuritis) in chickens raised on a diet deficient in that substance. He named the substance "vitamine" because he believed it was necessary to life and it was a chemical amine. The "e" at the end was later removed when it was recognized that vitamins need not be amines.
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Zinc: A mineral essential to the body, zinc is a constituent of many enzymes that permit chemical reactions to proceed at normal rates. It is involved in the manufacture of protein (protein synthesis) and in cell division. Zinc is also a constituent of insulin , and is concerned with the sense of smell.
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