Maximal tear secretion evoked by controlled stimulation of corneal sensory nerves in healthy individuals and dry eye subjects.

PURPOSE: To measure, the tear flow changes evoked in healthy subjects and dry eye disease (DED) patients by controlled sensory stimulation of the eye surface with i-Onion™, a new stimulation device. METHODS: Sensory corneal nerves were stimulated with an instrument (i-Onion™) that ejects puffs of CO...

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Detalles Bibliográficos
Autores: Merino ML, Belmonte J, Rosas J, Acosta MC, Gallar J, Belmonte C
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Instituto de Investigación Biomédica y Sanitaria de Alicante (ISABIAL)
Repositorio:r-ISABIAL. Repositorio Institucional de Producción Científica del Instituto de Investigación Biomédica y Sanitaria de Alicante
OAI Identifier:oai:isabial.fundanetsuite.com:p9372
Acceso en línea:https://isabial.portalinvestigacion.com/publicaciones9372
Access Level:acceso abierto
Palabra clave:Corneal nerve stimulation
Dry eye disease
Eye exploration
Sensory nerves
Sjögren's syndrome
Tear glands
Tear secretion
Tearing
Descripción
Sumario:PURPOSE: To measure, the tear flow changes evoked in healthy subjects and dry eye disease (DED) patients by controlled sensory stimulation of the eye surface with i-Onion™, a new stimulation device. METHODS: Sensory corneal nerves were stimulated with an instrument (i-Onion™) that ejects puffs of CO(2) gas (99.9%) at 200?ml.min(-1) for 3s, delivered 5?mm from the cornea. Using Schirmer test strips, tear volumes were measured over 3?min in the cornea of one eye before (basal tear volume -BTV) and in the other eye after stimulation of the sensory nerves with CO(2) (stimulated tear volume -STV). These measurements were obtained from a control group of adults of either sex (17 students aged 20-30 and 29 subjects without signs of dry eye aged 25-61), a cohort of DED patients (aged 34-75) that included 12 asymptomatic, suspected DED subjects (Schirmer <7?mm and/or TBUT <10s), and 30 Sjögren's syndrome (SS) patients. RESULTS: CO(2) stimulation significantly increased the tear volume (BTV?=?14.6?±?1.0?mm, STV?=?19.0?±?1.1?mm: n?=?46) in 78% of control subjects, reflecting a mean tear reserve volume (TRV?=?STV-BTV) of 4.4?±?0.8?mm. Individual differences were wide, and while no increase in reflex tearing was evoked in 30% of subjects with a BTV >10?mm, the remaining 70% responded vigorously to stimulation, even those with a BTV >18?mm. Asymptomatic DED subjects displayed weaker responses to CO(2) stimulation, with lower STVs. Both the BTV and STV of SS patients were low, significantly below those of the healthy controls. CONCLUSIONS: Measuring the rise in reflex tearing volume evoked by controlled corneal stimulation provides objective information about the tear glands' secretory capacity in health and disease.