| 单词 | river blindness | |||
| 释义 | river blindnessriver blindnessriver blindness
river blindnessriver blindnessoronchocerciasis,disease caused by the parasitic nematode worm Onchocerca volvulus. The worm larvae are transmitted by the bites of blackflies (genus Simulium) that live in fast moving streams. Inside the body the worms form disfiguring skin nodules, where they mate. Their tiny larvae, or microfilariae, migrate through the skin, causing severe itching. If the infection reaches the area of the eye, allergic reaction to the microfilariae can cause blindness.Tests can now detect infestation before the disease has progressed, and the new drugs ivermectin, which kills the larvae, and amocarzine, which kills adult forms, have begun to help control the disease. Blackfly eradication programs have had limited success because the flies can quickly develop resistance to pesticides. River blindness, which occurs primarily in Africa, Central and South America, and Yemen, affects an estimated 18 million people. In Africa, two strains have been identified, a savanna strain and a forest strain. The forest strain does not usually lead to blindness, but it does cause severe skin symptoms (lesions, itching, discoloration, change in texture) that can result in social ostracism. river blindnessoc·u·lar on·cho·cer·ci·a·sisriver blindnessblindness(blind'nes)Blindness may be caused by diseases of the lens, retina, or other eye structures; diseases of the optic nerve; or lesions of the visual cortex or pathways of the brain. A small number of infants are born blind, but far more people become blind during life. In the U.S., blindness due to infection is rare, but worldwide diseases like trachoma and onchocerciasis are relatively common causes of severe visual impairment. In malnourished people, vitamin A deficiency is an important cause of blindness. A variety of free services are available for the blind and physically handicapped. Talking Books Topics, published bimonthly in large-print, cassette, and disc formats, is distributed free to the blind and physically handicapped who participate in the Library of Congress free reading program. It lists recorded books and magazines available through a national network of cooperating libraries and provides news of developments and activities in library services. Subscription requests may be sent to Talking Books Topics, CMLS, P.O. Box 9150, Melbourne, FL 32902-9150. amnesic color blindness color blindnesscortical blindnessday blindnessHemeralopia.eclipse blindnessgreen blindnessAglaucopsia.hysterical blindnesslegal blindnessletter blindnessnight blindnessNyctalopia (1).note blindnessobject blindnesspsychic blindnessred-green blindnessRed-green color blindnessred-green color blindnessriver blindnessSee: onchocerciasissnow blindnesssolar blindnessEclipse blindness.taste blindnesstransient monocular blindnessEtiologyIn older adults, causes of carotid atherosclerosis include smoking, diabetes mellitus, hypertension, obesity, and hypercholesterolemia. When atherosclerotic plaques form within the carotid artery, they may ulcerate. The exposed endothelium within the artery becomes a focus of inflammation and blood clotting. Blindness occurs when tiny clots from the carotid arteries embolize to the ophthalmic arteries. SymptomsPatients often describe a dark shade descending into the field of vision. At the same time they may have other stroke symptoms, e.g., difficulty with speech or weakness of the hand on the side opposite the affected eye. TreatmentA patient who may have carotid atherosclerosis should begin taking aspirin or other antiplatelet drugs if these are tolerated. Blood pressure and lipid levels should be controlled. The patient should be referred for noninvasive evaluation of blood flow through the carotid arteries, e.g., ultrasonography. If the carotid arteries are significantly blocked, the patient and physician should consider the risks and benefits of carotid endarterectomy. violet blindnessword blindnessAlexia.river blindnessSee ONCHOCERCIASIS.onchocerciasisriver blindness
Synonyms for river blindness
|
|||
| 随便看 |
|
英语词典包含2567994条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。