title: The association of contact lens solution use and Acanthamoeba keratitis.
abstract: OBJECTIVE
  To investigate Acanthamoeba keratitis (AK) risk factors. Diagnosis of AK, a rare but serious corneal infection, has recently increased significantly at the University of Illinois at Chicago (UIC) Cornea Service.
  
  
  METHODS
  Retrospective case-control study.
  
  
  METHODS
  settings: University, tertiary care hospital. patients: Fifty-five AK cases with contact lens use were diagnosed between May 1, 2003 and September 15, 2006. Clinic-matched controls with contact lens use were recruited. Subjects completed surveys targeting lens hygiene, contact lens solution use, and water exposure. main outcome measure: Acanthamoeba keratitis.
  
  
  RESULTS
  Thirty-nine (73.6%) cases and 113 (65.3%) controls participated; 38 cases had complete contact lens data. Thirty-five of 38 cases (92.1%) and 47 of 100 controls (47.0%) used soft lenses. Analysis was performed on 30 cases and 39 controls with matched pairs with soft lens use. Exclusive use of Advance Medical Optics (AMO) Complete MoisturePlus Multi-Purpose Solution was independently associated with AK in multivariable analysis (55.2% vs 10.5%; odds ratio [OR], 16.67; 95% confidence interval [CI] 2.11 to 162.63; P = .008). However, 38.8% of cases reported no use of AMO Complete MoisturePlus Multi-Purpose Solution either alone or in combination with other solutions. Although not statistically significant, additional hygiene-related variables (solution "reuse," lack of "rubbing," and showering with lenses) suggest a pattern of risk.
  
  
  CONCLUSIONS
  AMO Complete MoisturePlus Multi-Purpose Solution use is independently associated with AK among soft contact lens users. However, it does not explain all cases, suggesting additional factors. Further research into environmental risk factors and hygiene practices is warranted, especially considering this is the second outbreak of an atypical, contact lens-related infection.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA. charjosl@uic.edu
authors.forename: Charlotte E
authors.initials: CE
authors.lastname: Joslin
authors.forename: Elmer Y
authors.initials: EY
authors.lastname: Tu
authors.forename: Megan E
authors.initials: ME
authors.lastname: Shoff
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Booton
authors.forename: Paul A
authors.initials: PA
authors.lastname: Fuerst
authors.forename: Timothy T
authors.initials: TT
authors.lastname: McMahon
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Anderson
authors.forename: Mark S
authors.initials: MS
authors.lastname: Dworkin
authors.forename: Joel
authors.initials: J
authors.lastname: Sugar
authors.forename: Faith G
authors.initials: FG
authors.lastname: Davis
authors.forename: Leslie T
authors.initials: LT
authors.lastname: Stayner
mesh_terms: D000048:Acanthamoeba / Q000302:isolation & purification*; D015823:Acanthamoeba Keratitis / Q000209:etiology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D018639:Contact Lens Solutions / Q000009:adverse effects*; D003263:Contact Lenses, Hydrophilic / Q000469:parasitology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D018639:Contact Lens Solutions