Interaction of corneal nociceptive stimulation and lacrimal secretion. | |
MedLine Citation:
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PMID: 20554608 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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PURPOSE: To investigate the interaction between corneal stimuli at different positions and tear secretion and to establish relationships between nociceptive stimuli detection thresholds and stimulated tearing. METHODS: Using a computerized Belmonte-esthesiometer, mechanical and chemical stimuli, from 0% to 200% of the threshold in 50% steps, were delivered (in random order) to the central and peripheral (approximately 2-mm inside the limbus) cornea during four separate sessions to 15 subjects. Immediately after each stimulus, tear meniscus height (TMH) was measured using optical coherence tomography to quantify the amount of lacrimal secretion, and subjects reported whether they felt tears starting to accumulate in their eyes. Thresholds (50% detection) for detection of tearing were estimated. RESULTS: TMH increased with increasing stimulus intensity (P < 0.05), and the overall increase was higher with central stimulation than with peripheral stimulation (P < 0.05). The changes in TMH with threshold-scaled stimulus intensity depended on test location (P < 0.05) and stimulus modality (P < 0.05). The maximum intensity of mechanical stimulation of the central cornea induced the greatest TMH (all P < 0.05). For chemical stimulation, the stimulus intensity required to induce detectable tearing was higher than that required to detect a stimulus and higher in the periphery than at the center (all P < 0.05). CONCLUSIONS: Noxious mechanical and chemical stimuli evoked measurable tear secretion, with central corneal mechanical stimulation evoking the strongest lacrimation reflex. Central mechanical corneal stimulation is the most effective stimulus-position pairing and appears to be the major sensory driving force for reflex tear secretion by the lacrimal functional unit. |
Authors:
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Ping Situ; Trefford L Simpson |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2010-06-16 |
Journal Detail:
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Title: Investigative ophthalmology & visual science Volume: 51 ISSN: 1552-5783 ISO Abbreviation: Invest. Ophthalmol. Vis. Sci. Publication Date: 2010 Nov |
Date Detail:
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Created Date: 2010-10-28 Completed Date: 2010-12-07 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 7703701 Medline TA: Invest Ophthalmol Vis Sci Country: United States |
Other Details:
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Languages: eng Pagination: 5640-5 Citation Subset: IM |
Affiliation:
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Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
MeSH Terms | |
Descriptor/Qualifier:
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Adolescent Adult Air Carbon Dioxide Cornea / innervation* Female Humans Hypesthesia Lacrimal Apparatus / secretion* Male Middle Aged Nerve Fibers / physiology* Neurons, Afferent / physiology Neurons, Efferent / physiology Nociceptors / metabolism* Physical Stimulation Reflex / physiology Sensory Receptor Cells / physiology* Stimulation, Chemical Tears / secretion* Tomography, Optical Coherence Young Adult |
Chemical | |
Reg. No./Substance:
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124-38-9/Carbon Dioxide |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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