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Cortical Blindness
Cortical Blindness A person with cortical blindness will have normal eyes and normal optic nerves but, nevertheless, will not be able to see. The cause of the blindness is with the cortex or surface of the brain that contains 32 or more sites for visual information processing. More recently, the preferred term for such individuals is cortical visual impairment, because many people will not be totally blind but will exhibit unusual visual losses; for example, they may be blind to stationary objects but be able to see moving objects.
RELATED TERMS--------------------------------------
Cortical
Having to do with the cortex, the outer portion of an organ.
Blindness
Legal blindness is defined as: 1) visual acuity of 20/200 (only being able to see the big E on the eye chart) or less in the best eye even with the eyes corrected by glasses or contact lenses; or, 2) The peripheral visual field is reduced to 20 degrees of visual angle or less. Twenty degrees of visual angle is about the size of a one foot ruler held at arms length.
Cortex
The outer layer of the cerebrum, densely packed with nerve cells.
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."" "
Impairment
A defect in organ function or whole body system, which may be temporary or permanent (eg. hemiplegia).
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.
SIMILAR TERMS--------------------------------------
Cort-dome
Cort-dome is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): hydrocortisone.
Cortalone
Cortalone is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): prednisolone.
Cortan
Cortan is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): prednisone.
Cortef
Cortef is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): hydrocortisone.
Cortef acetate
Cortef acetate is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): hydrocortisone acetate.
Cortenema
Cortenema is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): hydrocortisone.
Cortex
The outer layer of the cerebrum, densely packed with nerve cells.
Cortex, adrenal
The outer portion of the adrenal gland located on top of each kidney. The adrenal cortex produces steroid hormones which regulate carbohydrate and fat metabolism and mineralocorticoid hormones which regulate salt and water balance in the body.
Cortical
Having to do with the cortex, the outer portion of an organ.
Cortical magnification factor
Defined as millimeters of cortex per degree of visual angle.
Corticaltectal pathway
Pathway from the cortex to the superior colliculi.
Corticoids
Substances similar to the hormone of the adrenal glands called cortisone; corticoids are differentiated into two groups – mineralocorticoids and glucocorticoids applied both locally and systemically, mainly as anti-phlogistics, immunosuppressives, anti-asthmathics or in the treatment of an allergy.
Corticosteroid
Hormones produced by the adrenal gland which are important to almost every function of cells and organs. They are divided into two groups: glucocorticoids and mineralocorticoids. Glucocorticoids regulate protein, carbohydrate, and fat metabolism. Mineralocorticoids regulate electrolyte balances.
Corticosteroid allergy
A delayed allergic reaction to corticosteroid (drugs similar to cortisone). This occurs in 1-4% of people who use corticosteroids for asthma or other allergic diseases. A positive patch test to a corticosteroid means the patient cannot use that particular steroid. Although cross allergy between corticosteroids is common, such patients usually can tolerate another corticosteroid.
Corticosteroid drugs
Anti-inflammatory drugs that interfere with the immune system, suppress it and thereby dampen the inflammatory overreaction. They can be used to treat a number of allergic diseases - e.g. allergic rhinitis, eczema and rheumatoid arthritis. Corticosteroid drugs come as creams, inhalants, tablets and eye drops.
Corticosteroid hormones
Hormones produced by the adrenal glands.
Corticosteroids
Sometimes referred to just as 'steroids'. Hormones (which occur naturally) which have a variety of actions when given therapeutically. Usually administered for their anti-inflammatory effect. Their use is limited by unwanted side-effects which may sometimes be serious.
Corticotropin
Corticotropin is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): corticotropin.
Corticotropin-releasing hormone
A hormone made by the hypothalamus that stimulates the release of corticotropin by the anterior pituitary gland. Corticotropin-releasing hormone is abbreviated and often referred to as CRH.
Corticotropin-Releasing Hormone (CRH)
The hormone released from the hypothalamus. It interacts with the pituitary to produce ACTH. This hormone uses cyclic AMP for its second messenger.
Cortifoam
Cortifoam is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): hydrocortisone acetate.
Cortisol
The hormone released from the adrenal glands in response to stress or low blood glucose. Its primary mode of action in times of stress is to shut down eicosanoid synthesis. Its synthesis in the adrenal gland requires the second messenger, cyclic AMP.
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.
Cortisone acetate
Cortisone acetate is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): cortisone acetate.
Cortisporin
Cortisporin is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): bacitracin zinc; hydrocortisone; neomycin sulfate; polymyxin b sulfate.
Cortone
Cortone is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): cortisone acetate.
Cortril
Cortril is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): hydrocortisone.
Cortrophin-zinc
Cortrophin-zinc is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): corticotropin-zinc hydroxide.
Cortrosyn
Cortrosyn is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): cosyntropin.
PREVIOUS AND NEXT TERMS--------------------------------------
Cone
One of the two light receiving retinal cells (the other is the rod) that is responsible for daylight vision (e.g., color vision, high visual acuity, bright light vision). The area of the retina that provides central or reading vision, known as the fovea, contains only cones.
Cone Dystrophy
Also sometimes referred to as cone degeneration. The cones of the eye degenerate over time leading to visual acuity between 20/50 and 20/200 – legal blindness. There may be a progressive vision loss, abnormal color vision and photophobia. No treatment is available, except for dark sunglasses for the photophobia. Patients with cone dystrophies and cone degenerations benefit for rehabilitation services.
Cone Rod Degeneration
Also called cone-rod dystrophy. Leads to a loss of visual acuity between 20/25 to 20/400 – legal blindness. First there is a loss of cone photoreceptors followed by a loss of rod photoreceptors. Visual fields may be restricted, abnormal color vision and photophobia. No treatment is available.
Conjunctivitis
An inflammation of the thin transparent tissue layer within the eye containing blood vessels. The conjunctiva covers the outer surface of the eyeball, starting at the limbus (edge of the cornea) and extends backward to form a recess under each lid before coming forward and covering the inside surface of each eyelid. It contains mucous secreting cells that allow the eye to move smoothly in various directions. It also helps lubricate the cornea during blinking. A contagious and treatable condition.
Cornea
The front part of the eye that acts as a window for the entrance of light rays. It is attached to the other outer coat of the eye, the sclera; the white part of the eye. The cornea provides a significant amount of focusing power for the eye (the rest is provided by the lens). Because it has many nerve fibers, an injury or foreign body causes significant pain and discomfort.
Cortical Blindness
Cover Test
A test for a muscle imbalance. While the person is looking at a distant object, one eye is covered and then uncovered (cover-uncover). This is repeated on the other eye. Finally it is performed on both eyes, covering one then the other (alternate-cover). If one or both eyes shift during this test, there is a problem with alignment of the eyes. The misalignment with the eyes often cannot be seen with both eyes opened.
Cipro IV
Cipro I.V. (ciprofloxacin) is one of the most prescribed fluoroquinolone antibiotics.
Cupping of the optic disc
A depression of the optic nerve where the optic nerve leaves the eye. In glaucoma, the cup may be enlarged indicating damage to the nerves leading from the eye to the brain.
Cycloplegia
A paralysis of the ciliary muscles following the instillation of eye drops. This produces a loss of accommodation or focusing ability. With the lens relaxed, a better estimate of the refractive error is possible in most cases. Most cycloplegic eye drops also dilate the pupil. Cycloplegia may last from a few hours to several days, depending on certain factors such as skin color – the lighter the longer.
Ciflox
A potent broad spectrum oral antibiotic that, when first introduced, represented a breakthrough in fighting infectious diseases. Ciflox is also known as Cipro. Produced by Bayer.
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