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tear break-up test

(tēr) ABBR: TBUT. A test for dry eyes in which fluorescein sodium is applied to the cornea. The amount of time it takes for the first dry spots to appear on the cornea is determined. A TBUT time of less than 10 sec-suggests poor tear film stability.

tear film

A liquid consisting of lipids, water, and mucin that coats the outer surface of the eye, lubricating it.

PATIENT CARE: A reduction in the tear film causes a sensation of a dry or gritty eye, such as is seen in Sjögren Syndrome, keratoconjunctivitis, sicca, disorders of the lacrimal gland, and other conditions. Keeping eyelids clean, using artificial tears, and withholding medications that may reduce the tear film can prove helpful for some patients. Other treatments may include the wearing of moisture chambers around the eye, and eye lid surgery. Topical lubricants can be used for symptomatic relief.


(tēz) [Old English taesan, to pluck] To separate a tissue into minute parts with a needle to prepare it for microscopy.


(tē′spoon″) ABBR: tsp. A household measure equal to approx. 5 mL. Teaspoons used in the home vary from 3 to 6 mL. Because household measures are not accurate, when a teaspoon dose is prescribed or ordered, 5 mL of the substance should be given.


(tēt) 1. The nipple of the mammary gland. SYN: papilla mammae. SEE: breast. 2. Any protuberance resembling a nipple.


[Acronym for totally endoscopic coronary artery bypass] A robot-controlled procedure in which the left internal mammary artery is used to bypass the left anterior descending coronary artery without the use of sternotomy. The procedure is a form of minimally invasive coronary artery surgery. In TECAB, several small portholes are made in the chest wall to insert a video camera and robot-controlled and stabilized surgical instruments to improve surgical dexterity and eliminate tremor.


(tek-nē′sh(ē-)ŭm) [Gr. technētikos, made, artificial + -ium (1)] SYMB: Tc. A synthetic, silvery gray, crystalline chemical element, atomic number 43, average atomic weight (mass) 98.9062. It is a transition metal having a number of isotopes, all of which are radioactive and have various half-lives. Its isotope, technetium-99, is used in nuclear medicine for a wide variety of diagnostic tests. SEE: technetium-99m.


(tek-nē′sh(ē-)ŭm-nīn′tē-nīn″) SYMB: 99mTc. A radioactive isotope of technetium having a half-life of 6 hr, in which the “m” means that it is a metastable isotope. 99mTc is used in nuclear medicine for a wide variety of diagnostic tests and imaging studies, e.g., myocardial perfusion scans, bone ...

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