title: Effect of the osmolarity change in multipurpose solutions induced by an improper contact lens case cleaning procedure.
abstract: OBJECTIVE
  To determine whether variations in multipurpose disinfecting solution (MPDS) storage osmolarity from inappropriate contact lens (CL) case cleaning affect ocular surface integrity and wearer comfort.
  
  
  METHODS
  There were twenty contact lens cases (study CLCs) in the study group. Ten were filled with ReNu Multiplus(®) and 10 with SoloCare Aqua™ (MPDS-1 and -2, respectively) and kept closed for 8h; the cases were then emptied and kept open for air-drying for 16h. This procedure was carried out every day for two months. Storage solution osmolarity was measured on days 0, 15, 30, 45 and 60. Ten subjects were then fitted with both month-old lenses stored in the study CLCs and with new lenses stored in new cases with fresh solution for 24h (control CLCs). Symptoms, tear osmolarity and percentage of subjects whose conjunctival hyperaemia and ocular surface staining scores changed were determined after 1h of wear.
  
  
  RESULTS
  Study CLC osmolarity increased in both solutions after two months (p<0.05). For MPDS-1 there were differences in stinging between study CLCs and control CLCs after 10min of CL wear (p=0.04), and in comfort after 10 (p=0.035) and 60min wear (p=0.042). Significant (p<0.05) differences between study CLC and control CLC groups were also found for MPDS-2 in limbal hyperaemia (study: 50% change; control: 0% change) and bulbar and corneal staining (study: 80% change; control: 20% change).
  
  
  CONCLUSIONS
  The stored-MPDS osmolarity increase caused by air-drying the CLCs could affect the ocular surface. This increase might reduce lens wear comfort.
authors.affiliation: Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, Valladolid, Spain; CIBER-BNN, Valladolid, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Pinto-Fraga
authors.affiliation: Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, Valladolid, Spain; CIBER-BNN, Valladolid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Abengózar-Vela
authors.affiliation: Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, Valladolid, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: López-Miguel
authors.affiliation: Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, Valladolid, Spain; CIBER-BNN, Valladolid, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Martín-Montañéz
authors.affiliation: Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, Valladolid, Spain; CIBER-BNN, Valladolid, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: López de la Rosa
authors.affiliation: Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, Valladolid, Spain; CIBER-BNN, Valladolid, Spain. Electronic address: mjgonzalez@ioba.med.uva.es.
authors.forename: María J
authors.initials: MJ
authors.lastname: González-García
mesh_terms: D000328:Adult; D018639:Contact Lens Solutions / Q000009:adverse effects* / Q000032:analysis / Q000737:chemistry*; D003262:Contact Lenses, Extended-Wear / Q000009:adverse effects*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017743:Equipment Reuse; D058447:Eye Pain / Q000139:chemically induced* / Q000175:diagnosis / Q000517:prevention & control; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000139:chemically induced* / Q000473:pathology / Q000517:prevention & control; D007634:Keratitis / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control; D008297:Male; D009994:Osmolar Concentration; D013666:Tears / Q000737:chemistry*
chemical_list: D018639:Contact Lens Solutions
keywords: Contact lens; Contact lens case cleaning; Osmolarity