20/20: See; Twenty-twenty.
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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Amblyopia: Partial or complete loss of vision in one eye caused by conditions that affect the normal development of vision. These conditions include strabismus , in which the eyes are crossed inward ( esotropia ) or turned outward ( exotropia ) and anisometropia , in which there is a major difference in refractive error between the two eyes from nearsightedness , farsightedness , or astigmatism . Less common causes of amblyopia include ptosis (drooping) of one eyelid, disease of the cornea (preventing light from entering the eye), congenital cataract , and injury to the eye of a young child.
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Anesthesia: Loss of feeling or awareness. A general anesthetic puts the person to sleep. A local anesthetic causes loss of feeling in a part of the body such as a tooth or an area of skin without affecting consciousness. Regional anesthesia numbs a larger part of the body such as a leg or arm, also without affecting consciousness. The term "conduction anesthesia" encompasses both local and regional anesthetic techniques. Many surgical procedures can be done with conduction anesthesia without significant pain. In many situations, such as a C-section, conduction anesthesia is safer and therefore preferable to general anesthesia. However, there are also many types of surgery in which general anesthesia is clearly appropriate.
Anterior: The front, as opposed to the posterior. The anterior surface of the heart is toward the breast bone (the sternum).
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Anterior chamber: The space in the eye that is behind the cornea and in front of the iris.
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Antibiotic: A drug used to treat infections caused by bacteria and other microorganisms. Originally, an antibiotic was a substance produced by one microorganism that selectively inhibits the growth of another. Synthetic antibiotics, usually chemically related to natural antibiotics, have since been produced that accomplish comparable tasks.
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Arthritis: Inflammation of a joint. When joints are inflamed they can develop stiffness, warmth, swelling, redness and pain. There are over 100 types of arthritis. (see osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, lupus, gout, pseudogout).
Astigmatism: A common form of visual impairment in which part of an image is blurred, due to an irregularity in the curvature of the front surface of the eye, the cornea. The curve of the cornea is shaped more like an American football or a rugby ball rather than a normal spherical basketball. Light rays entering the eye there are not uniformly focused on the retina. Rays entering through the more-curved surface are focused before the rays coming through the less-curved surface. The light is focused clearly along one plane but is blurred along the other. The result is blurred vision at all distances. Only part of what you are looking at is in clear focus at any one time.
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Autoimmune: Pertaining to autoimmunity, a misdirected immune response that occurs when the immune system goes awry and attacks the body itself.
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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.
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."
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Breastfeeding: Feeding a child human breast milk . According to the American Academy of Pediatrics , human breast milk is preferred for all infants. This includes even premature and sick babies, with rare exceptions. It is the food least likely to cause allergic reactions; it is inexpensive; it is readily available at any hour of the day or night; babies accept the taste readily; and the antibodies in breast milk can help a baby resist infections.
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Cataract: A clouding of the lens of the eye. The normally clear aspirin-sized lens of the eye starts to become cloudy. The result is much like smearing grease over the lens of a camera. It impairs normal vision.
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Cataract surgery: Removal of the clouded lens (the cataract ) in its entirety by surgery, usually followed by replacement of the lens with an intraocular lens (IOL) made of plastic, silicone, acrylic or other material. The operation typically takes about an hour, is done under local anesthetic only, and does not require hospitalization.
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Cell: The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane .
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Childhood: (1) The time for a boy or girl from birth until he or she is an adult. (2) The more circumscribed period of time from infancy to the onset of puberty .
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Condition: The term "condition" has a number of biomedical meanings including the following: - An unhealthy state, such as in "this is a progressive condition."
- A state of fitness, such as "getting into condition."
- Something that is essential to the occurrence of something else; essentially a "precondition."
- 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.
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.
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Corneal: Pertaining to the cornea, the clear front window of the eye that transmits and focuses light into the eye.
Corneal transplant: The replacement of the clear window on the front of the eye (cornea) by a healthy cornea. The procedure is typically done under local anesthesia in an outpatient setting. Transplantation of the cornea may be indicated in cases of severe scarring of the cornea by injury or infection (as with corneal ulcers) and in genetic disorders such as keratoconus (inherited corneal thinning with visual distortion) and Fuch's dystrophy (inherited corneal clouding with visual loss). The very limited blood supply of the cornea greatly reduces the risk of transplant rejection. Corneal transplants generally function effectively for many years.
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).
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Diabetic retinopathy: A common complication of diabetes affecting the blood vessels in the retina (the thin light-sensitive membrane that covers the back of the eye ). If untreated, it may lead to blindness. If diagnosed and treated promptly, blindness is usually preventable.
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Disease: Illness or sickness often characterized by typical patient problems (symptoms) and physical findings (signs). Disruption sequence: The events that occur when a fetus that is developing normally is subjected to a destructive agent such as the rubella (German measles) virus.
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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Eye: The organ of sight. The eye has a number of components. These components include but are not limited to the cornea, iris, pupil, lens, retina, macula, optic nerve, choroid and vitreous.
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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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Film: Slang shortening of X-ray film, an X-ray, a radiograph.
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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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.
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Health: As officially defined by the World Health Organization, a state of complete physical, mental, and social well-being, not merely the absence of disease or infirmity.
HIV: Acronym for the Human Immunodeficiency Virus , the cause of AIDS (acquired immunodeficiency syndrome). HIV has also been called the human lymphotropic virus type III, the lymphadenopathy-associated virus and the lymphadenopathy virus . No matter what name is applied, it is a retrovirus. (A retrovirus has an RNA genome and a reverse transcriptase enzyme. Using the reverse transcriptase , the virus uses its RNA as a template for making complementary DNA which can integrate into the DNA of the host organism).
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Hypertension: High blood pressure , defined as a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
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Immunodeficiency: Inability to mount a normal immune response. Immunodeficiency can be due to a genetic disease or acquired as in AIDS due to HIV.
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Implant: 1. To embed; to set in firmly. In embryology, the fertilized egg implants in the uterine lining 6 or 7 days after conception (fertilization). In medicine today, many things may be implanted.
2. That which is embedded. For example: lens implants, breast implants, cochlear implants, defibrillator implants, pacemaker implants, etc.
Implantation: The act of setting in firmly.
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Incision: A cut. When making an incision, a surgeon is making a cut.
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.
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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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Informed consent: A process in which a person learns key facts about a clinical trial, including potential risks and benefits, before deciding whether or not to participate in a study. Informed consent continues throughout the trial.
Injure: To harm, hurt, or wound. The word injure may be in physical or emotional sense. Treadmill machines may injure anyone who gets on one. Sexual molestation injures children. From the Latin injuria meaning injury.
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.
Insertion: Chromosome abnormality due to insertion of a segment from one chromosome into another chromosome.
Intraocular: In the eye. The intraocular pressure is the pressure within the eye.
Intraocular lens: An artificial lens made of plastic, silicone, acrylic or other material that is implanted inside the eye during cataract surgery. Abbreviated IOL.
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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.
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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.)
Keratectomy: Removal of part of the cornea. This can be done by surgical excision or by laser. One such laser procedure is PRK (photorefractive keratectomy).
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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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LASIK : Abbreviation standing for laser-assisted in situ keratomileusis, a kind of laser eye surgery designed to change the shape of the cornea to eliminate or reduce the need for glasses and contact lenses in cases of severe myopia ( nearsightedness ).
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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.
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Lubricant: An oily or slippery substance. A vaginal lubricant may be helpful for women who feel pain during intercourse because of vaginal dryness.
Lupus: A chronic inflammatory condition caused by an autoimmune disease. An autoimmune disease occurs when the body's tissues are attacked by its own immune system. Patients with lupus have unusual antibodies in their blood that are targeted against their own body tissues.
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Medical device: 1. Broadly, any physical item used in medical treatment, from a cardiac pacemaker to a wheelchair.
2.In insurance terms, usually synonymous an assistive device , although it may include items more frequently thought of as medical supplies, such as dressings needed for wound care at home or syringes for self-administration of insulin .
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Medical history: 1. In clinical medicine, the patient's past and present which may contain clues bearing on their health past, present, and future. The medical history, being an account of all medical events and problems a person has experienced, including psychiatric illness, is especially helpful when a differential diagnosis is needed.
2. The history of medicine.
Medication: 1. A drug or medicine. 2. The administration of a drug or medicine. (Note that "medication" does not have the dangerous double meaning of "drug.")
Myopia: Nearsightedness, the ability to see close objects more clearly than distant objects.
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Nearsightedness: The ability to see near objects more clearly than distant objects. Also called myopia.
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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.
Numb: Numb, or numbness is a loss of the sensation of feeling in an area of the body. Numbness results from damage to, or impaired function of, the nerves that supply the affected area. The function of the nerves may be impaired by numerous causes including some chronic diseases ( diabetes mellitus , thyroid disease, migraine ), trauma , toxins, decreased blood supply due to atherosclerosis or other conditions, electrolyte imbalances, and pressure on the spinal nerves from herniated discs or other diseases of the spine .
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Ocular: Having to do with the eye.
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Ointment: A medication preparation that is applied topically (onto the skin). An ointment has an oil base whereas a cream is water-soluble. (The word ointment comes from the Latin ungere meaning anoint with oil).
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Operating room: A facility equipped for performing surgery. Abbreviated OR.
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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Posterior: The back or behind, as opposed to the anterior.
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Posterior chamber: The space in the eye behind the iris and in front of the lens . (The iris is the colored ring of tissue that regulates the amount of light entering the eye by adjusting the size of the pupil . The lens is the transparent biconvex body in the eye that refracts light. By "biconvex" is meant that it is convex, that it protrudes, on both sides.)
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Postoperative: After surgery. As opposed to preoperative, before surgery.
Pregnant: The state of carrying a developing fetus within the body.
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Preoperative: Before surgery. As opposed to postoperative, after surgery.
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Prescription: A physician's order for the preparation and administration of a drug or device for a patient. A prescription has several parts. They include the superscription or heading with the symbol "R" or "Rx", which stands for the word recipe (meaning, in Latin, to take); the inscription, which contains the names and quantities of the ingredients; the subscription or directions for compounding the drug; and the signature which is often preceded by the sign "s" standing for signa (Latin for mark), giving the directions to be marked on the container.
Proliferative: Growing and increasing in number rapidly.
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Pseudoexfoliation syndrome: An eye condition that often leads to glaucoma. Called the pseudoexfoliation syndrome because deposits on the surface of the lens look like flakes of dandruff, as if the lens capsule has exfoliated (shed the flakes). It is also called exfoliation syndrome.
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).
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Range: In medicine and statistics, the difference between the lowest and highest numerical values. For example, if five premature infants are born weighing two, three, four, four, and five pounds respectively, the range of their birth weights is two to five pounds.
Recurrence: The return of a sign, symptom or disease after a remission. The reappearance of cancer cells at the same site or in another location is, unfortunately, a familiar form of recurrence.
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Refraction: In ophthalmology, the bending of light that takes place within the human eye.
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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.
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 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.
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Retinopathy: Any disease of the retina, the light-sensitive membrane at the back of the eye. The type of retinopathy is often specified. Arteriosclerotic retinopathy is retinal disease due to arteriosclerosis ("hardening of the arteries"). Diabetic retinopathy is retinal disease associated with diabetes. Hypertensive retinopathy is retinal disease due to high blood pressure. Etc.
Rheumatoid arthritis : An autoimmune disease which causes chronic inflammation of the joints, the tissue around the joints, as well as other organs in the body. Autoimmune diseases occur when the body tissues are mistakenly attacked by its own immune system. The immune system is a complex organization of cells and antibodies designed normally to "seek and destroy" invaders of the body, particularly infections. Patients with these diseases have antibodies in their blood which target their own body tissues, where they can be associated with inflammation. Because it can affect multiple other organs of the body, rheumatoid arthritis is referred to as a systemic illness and is sometimes called rheumatoid disease. While rheumatoid arthritis is a chronic illness (meaning it can last for years) patients may experience long periods without symptoms.
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Rupture: A break or tear in any organ (such as the spleen) or soft tissue (such as the achilles tendon). Rupture of the appendix is more likely among uninsured and minority children when they develop appendicitis.
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.
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Section: 1) In anatomy, a slice of tissue. A biopsy obtained by surgery is usually sectioned (sliced), and these sections are inspected under a microscope. 2) In obstetrics, short for Caesarian section. 3) In surgery, the division of tissue during an operation.
Sedative: A drug that calms a patient down, easing agitation and permitting sleep. Sedatives generally work by modulating signals within the central nervous system. These sedatives can dangerously depress important signals needed to maintain heart and lung function if they are misused or accidentally combined, as in the case of combining prescription sedatives with alcohol. Most sedatives also have addictive potential. For these reasons, sedatives should be used under supervision, and only as needed.
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.
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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Sleep : The body's rest cycle.
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Speculum: An instrument used to widen an opening to look within a passage or a cavity. For example, a speculum may be used to widen the opening of the vagina so that the cervix is more easily visible. Other examples include the nasal speculum to look up into the nostrils and the ear speculum to look within the ear canal at the ear drum. The term "speculum" is the Latin word for mirror.
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Steroid: A general class of chemical substances that are structurally related to one another and share the same chemical skeleton (a tetracyclic cyclopenta[a]phenanthrene skeleton).
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Stroke : The sudden death of some brain cells due to a lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain. A stroke is also called a cerebrovascular accident or, for short, a CVA.
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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.
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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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Syndrome: A set of signs and symptoms that tend to occur together and which reflect the presence of a particular disease or an increased chance of developing a particular disease.
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Tissue: A tissue in medicine is not like a piece of tissue paper. It is a broad term that is applied to any group of cells that perform specific functions. A tissue in medicine need not form a layer. Thus, - The bone marrow is a tissue;
- Connective tissue consists of cells that make up fibers in the framework supporting other body tissues; and
- Lymphoid tissue is the part of the body's immune system that helps protect it from bacteria and other foreign entities.
Transplant: The grafting of a tissue from one place to another, just as in botany a bud from one plant might be grafted onto the stem of another. The transplanting of tissue can be from one part of the patient to another (autologous transplantation), as in the case of a skin graft using the patient's own skin; or from one patient to another (allogenic transplantation), as in the case of transplanting a donor kidney into a recipient.
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.
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Uveitis: Inflammation of the uvea, the part of the eye that collectively refers to the iris, the choroid of the eye, and the ciliary body. The uvea provides most of the blood supply to the retina. Uveitis as a rule signifies inflammation involving the iris, choroid, and ciliary body -- all three components of the uveal tract.
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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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