title: Results of case-control studies support the association between contact lens use and Acanthamoeba keratitis.
abstract: BACKGROUND
  Acanthamoeba keratitis (AK) is ever more frequently reported in industrialized countries. The loss of the corneal surface integrity consequent to secondary microtrauma produced by the use of contact lens (CL) favors the penetration of the parasite into the corneal tissue.
  
  
  OBJECTIVE
  A scientific review was performed to investigate the association of CL wear as an Acanthamoeba keratitis (AK) risk factor.
  
  
  METHODS
  A computerized screening of 7834 Medline articles (4623 from PubMed; 3211 from Scopus) used a strict selection criteria of case-control studies involving CL wear and/or trauma.
  
  
  RESULTS
  The search yielded five case-control studies published from 1995 to 2012. All studies included showed a statistically significant positive association between AK and CL use, with a combined odds ratio (OR) of 10.21 (95%, confidence intervals [CI]; 3.57-27.64).
  
  
  METHODS
  All studies included showed a statistically significant positive association between AK and CL use, though with differing OR values.
  
  
  CONCLUSIONS
  Though rare, AK should be held in higher consideration when ophthalmologists are faced with CL users exhibiting simplex-like lesions associated with circular stromal infiltrates and disproportionate ocular pain in respect to the objective clinical picture.
authors.affiliation: Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Pacella
authors.forename: Giuseppe
authors.initials: G
authors.lastname: La Torre
authors.forename: Maria
authors.initials: M
authors.lastname: De Giusti
authors.forename: Chiara
authors.initials: C
authors.lastname: Brillante
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Lombardi
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Smaldone
authors.forename: Tommaso
authors.initials: T
authors.lastname: Lenzi
authors.forename: Fernanda
authors.initials: F
authors.lastname: Pacella
keywords: Acanthamoeba; contact lens; keratitis