| Tear flow dynamics in the human nasolacrimal ducts--a pilot study using dynamic magnetic resonance imaging. | |
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MedLine Citation:
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PMID: 15742210 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: Jones's theory of tear drainage suggests that the lacrimal sac fills when the eyelids are closed and empties into the nasolacrimal duct when the eyelids are open. This is aided by the contraction of the orbicularis muscle during each blink. This study was undertaken to ascertain the possibility of seeing the dynamic movement of tears in the nasolacrimal system during blinks using magnetic resonance dacryocystography (MR-DCG). METHODS: The sac was initially localized with a three-plane gradient echo sequence using a 1.5-T MRI platform. Fast, dynamic MR-DCG was carried out after we had instilled topically balanced salt solution (BSS) in five subjects and 0.5% gadolinium in seven subjects. The volunteers were asked to close and open their eyes during the fast imaging. The images were digitized to enable us to see the actual movement of fluid in the system. RESULTS: The tear movement was clearly seen as a bolus in the volunteers where BSS was used. The fluid passed into the nasolacrimal duct after several blinks when patent. The sac was never seen to empty completely. Though differential filling was seen between the upper and lower part of the sac, it was difficult to see the actual fluid movement in the volunteers when topical gadolinium was used. CONCLUSION: The findings of the study are supportive of the notion of fluid travel in the form of a bolus through the sac. Once a threshold volume is reached in the lower end of the sac, the fluid is seen to pass through the nasolacrimal duct. This happens after several blinks. |
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Authors:
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Shantha Amrith; Poh Sun Goh; Shih-Chang Wang |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2004-12-17 |
Journal Detail:
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Title: Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv für klinische und experimentelle Ophthalmologie Volume: 243 ISSN: 0721-832X ISO Abbreviation: Graefes Arch. Clin. Exp. Ophthalmol. Publication Date: 2005 Feb |
Date Detail:
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Created Date: 2005-03-02 Completed Date: 2005-04-25 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8205248 Medline TA: Graefes Arch Clin Exp Ophthalmol Country: Germany |
Other Details:
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Languages: eng Pagination: 127-31 Citation Subset: IM |
Affiliation:
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The Eye Institute, National University Hospital, Singapore. ophv14@nus.edu.sg |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Acetates
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administration & dosage Blinking / physiology Contrast Media Drug Combinations Eyelids / physiology Gadolinium Humans Magnetic Resonance Imaging / methods* Minerals / administration & dosage Nasolacrimal Duct / metabolism*, radiography Oculomotor Muscles / physiology Pilot Projects Sodium Chloride / administration & dosage Tears / secretion* |
| Chemical | |
Reg. No./Substance:
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0/Acetates; 0/BSS solution; 0/Contrast Media; 0/Drug Combinations; 0/Minerals; 7440-54-2/Gadolinium; 7647-14-5/Sodium Chloride |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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