title: Dry eye exacerbation in patients exposed to desiccating stress under controlled environmental conditions.
abstract: OBJECTIVE
  To determine if controlled environmental conditions can induce acute exacerbations of signs and symptoms in dry eye and asymptomatic subjects.
  
  
  METHODS
  Prospective cross-sectional study.
  
  
  METHODS
  Nineteen patients with dry eye and 20 asymptomatic controls were exposed to controlled low humidity (5% relative humidity, desiccating environment) for 2 hours in our Controlled Environmental Research Laboratory at the University of Valladolid. The patients completed the Single-Item Score Dry Eye Questionnaire and the following diagnostic tests were performed before and after exposure: tear osmolarity, phenol red thread test, conjunctival hyperemia, fluorescein tear film break-up time, Schirmer test, and ocular surface vital staining. Sixteen molecules in the tears samples were analyzed by multiplex bead analysis.
  
  
  RESULTS
  After exposure, the patients and controls had a significant (P ≤ .003) increase in corneal staining (from 0.68 ± 0.15 to 1.16 ± 0.14 and from 0.50 ± 0.15 to 1.30 ± 0.19, respectively), significantly decreased (P ≤ .01) fluorescein tear film break-up time values (from 2.78 ± 0.56 seconds to 1.94 ± 0.24 seconds and from 2.81 ± 0.24 seconds to 2.13 ± 0.19 seconds, respectively), and significantly increased (P ≤ .03) matrix metalproteinase 9 tear levels (from 10 054.4 ± 7326.6 pg/mL to 25 744.5 ± 13 212.4 pg/mL and from 10 620.5 ± 4494.3 pg/mL to 16 398.7 ± 5538.3 pg/mL, respectively). In the control group, the epidermal growth factor tear levels decreased significantly (P = .007; from 1872.1 ± 340.7 pg/mL to 1107.1 ± 173.6 pg/mL), and interleukin 6 levels increased significantly (P < .001; from 29.6 ± 5.8 pg/mL to 54.3 ± 8.3 pg/mL) after exposure.
  
  
  CONCLUSIONS
  Adult patients with mild-to-moderate dry eye and asymptomatic subjects of similar ages can experience acute exacerbation in an environmental chamber that resembles the sudden worsening that patients with dry eye experience daily.
authors.affiliation: Instituto Universitario de Oftalmobiología Aplicada, (IOBA), Universidad de Valladolid, Valladolid, Spain; Visión I+D, SL, Valladolid, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: López-Miguel
authors.affiliation: Instituto Universitario de Oftalmobiología Aplicada, (IOBA), Universidad de Valladolid, Valladolid, Spain.
authors.forename: Marisa
authors.initials: M
authors.lastname: Tesón
authors.affiliation: Instituto Universitario de Oftalmobiología Aplicada, (IOBA), Universidad de Valladolid, Valladolid, Spain; Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Valladolid, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Martín-Montañez
authors.affiliation: Instituto Universitario de Oftalmobiología Aplicada, (IOBA), Universidad de Valladolid, Valladolid, Spain; Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Valladolid, Spain.
authors.forename: Amalia
authors.initials: A
authors.lastname: Enríquez-de-Salamanca
authors.affiliation: Allergan, Inc, Irvine, California.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Stern
authors.affiliation: Instituto Universitario de Oftalmobiología Aplicada, (IOBA), Universidad de Valladolid, Valladolid, Spain; Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Valladolid, Spain.
authors.forename: Margarita
authors.initials: M
authors.lastname: Calonge
authors.affiliation: Instituto Universitario de Oftalmobiología Aplicada, (IOBA), Universidad de Valladolid, Valladolid, Spain; Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Valladolid, Spain. Electronic address: aluche@ioba.med.uva.es.
authors.forename: María J
authors.initials: MJ
authors.lastname: González-García
mesh_terms: D004396:Coloring Agents; D003228:Conjunctiva / Q000378:metabolism; D003315:Cornea / Q000378:metabolism; D003430:Cross-Sectional Studies; D015352:Dry Eye Syndromes / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D004780:Environment, Controlled; D005136:Eye Proteins / Q000378:metabolism; D005260:Female; D019793:Fluorescein / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D006801:Humans; D006813:Humidity; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D010637:Phenolsulfonphthalein; D011446:Prospective Studies; D013312:Stress, Physiological; D011795:Surveys and Questionnaires; D013666:Tears / Q000737:chemistry / Q000378:metabolism
chemical_list: D004396:Coloring Agents; D005136:Eye Proteins; D005456:Fluorescent Dyes; C042434:tear proteins; D010637:Phenolsulfonphthalein; D019793:Fluorescein