title: External ocular surface and lens microbiota in contact lens wearers with corneal infiltrates during extended wear of hydrogel lenses.
abstract: OBJECTIVE
  To determine whether carriage of microbes on the contact lens or ocular surfaces during extended wear (EW) with soft hydroxyethyl methacrylate (HEMA)-based contact lenses predisposes the wearer to adverse events.
  
  
  METHODS
  Participants (non-contact lens wearers) were enrolled in a clinical study involving wear of HEMA-based hydrogel lenses on a six night EW basis with weekly replacement. Type and number of bacteria colonizing the lower lid margins, upper bulbar conjunctiva, and contact lenses during EW after one night, 1 week, 1 month, and thereafter every 3 months for 3.5 years were determined. The association of bacteria with adverse responses was compared between carriers (defined as having significant microbes cultured from two or more samples with 1 year) and noncarriers, and the strength of the association was estimated using multivariate logistic regression.
  
  
  RESULTS
  Carriers of gram-positive bacteria on lenses (particularly coagulase negative staphylococci or Corynebacterium spp.) were approximately three and eight times more likely to develop contact lens-induced peripheral ulcers (CLPUs) and asymptomatic infiltrates (AIs), respectively. Staphylococcus aureus was most frequently isolated from lenses during CLPU. Carriers of gram-negative bacteria on lenses were five times more likely to develop contact lens-induced acute red eye (CLARE). Haemophilus influenzae was isolated most frequently from lenses during CLARE and AI events.
  
  
  CONCLUSIONS
  Bacterial carriage on contact lenses during EW predisposes the wearer to the development of corneal inflammatory events including CLARE, CLPU, and AI.
authors.affiliation: Brien Holden Vision Institute, University of New South Wales, Sydney, Australia. m.willcox@brienholdenvision.org
authors.forename: Mark
authors.initials: M
authors.lastname: Willcox
authors.forename: Savitri
authors.initials: S
authors.lastname: Sharma
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Naduvilath
authors.forename: Padmaja R
authors.initials: PR
authors.lastname: Sankaridurg
authors.forename: Usha
authors.initials: U
authors.lastname: Gopinathan
authors.forename: Brien A
authors.initials: BA
authors.lastname: Holden
mesh_terms: D000208:Acute Disease; D003228:Conjunctiva / Q000382:microbiology*; D003231:Conjunctivitis / Q000382:microbiology; D003262:Contact Lenses, Extended-Wear / Q000009:adverse effects; D003320:Corneal Ulcer / Q000382:microbiology; D005143:Eyelids / Q000382:microbiology; D016905:Gram-Negative Bacterial Infections / Q000150:complications; D016908:Gram-Positive Bacterial Infections / Q000150:complications / Q000382:microbiology; D006193:Haemophilus influenzae / Q000302:isolation & purification; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D007908:Lens, Crystalline / Q000382:microbiology*; D016013:Likelihood Functions; D016015:Logistic Models; D008689:Methacrylates; D016017:Odds Ratio; D012189:Retrospective Studies; D013211:Staphylococcus aureus / Q000302:isolation & purification
chemical_list: D008689:Methacrylates; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C005044:hydroxyethyl methacrylate