title: Ocular surface microbiome in meibomian gland dysfunction.
abstract: BACKGROUND
  To investigate the ocular microbiome in meibomian gland dysfunction in Auckland, New Zealand.
  
  
  METHODS
  Prospective, cross-sectional, observational, university-based study.
  
  
  METHODS
  Participants resident in New Zealand for ≥2 years (n = 157) were classified as normal (n = 66), mild (n = 41) or moderate-to-severe meibomian gland dysfunction (n = 50). Contact lens wear and anterior blepharitis status were recorded, as well as symptoms and clinical features.
  
  
  METHODS
  Bacteria collected from lid margin swabs, before and after gland expression, were isolated and identified by conventional microbiological culture techniques. Aerobic isolates were identified in all 157 participants, and both aerobic and anaerobic bacteria isolated in a subset of 87 subjects.
  
  
  METHODS
  Bacterial incidence according to meibomian gland dysfunction status RESULTS: Symptoms, bulbar hyperaemia, conjunctival staining, lipid layer grade and tear film stability, but not corneal staining, showed moderate association with meibomian gland dysfunction severity. Participants with and without meibomian gland dysfunction showed a similar microbiome, unaffected by gland expression. Anterior blepharitis, a common co-morbidity, was not an independent predictor of the microbiome. Sterile cultures were more common in contact lens wearers than non-wearers. The incidence of Staphylococcus aureus was higher than anticipated across all severity groups, and that of coagulase-negative Staphylococcus, Corynebacterium and streptococci was lower.
  
  
  CONCLUSIONS
  Modest differences in relative proportions of bacteria compared with other studies support climatic variations in the ocular surface microbiome. Similarity in microbiome profile, irrespective of meibomian gland dysfunction severity, anterior blepharitis presence or contact lens wear, suggests potential for commonality in treatment.
authors.affiliation: Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand.|School of Optometry and Vision Science, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand.
authors.forename: Grant A
authors.initials: GA
authors.lastname: Watters
authors.affiliation: School of Optometry and Vision Science, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand.
authors.forename: Philip R
authors.initials: PR
authors.lastname: Turnbull
authors.affiliation: Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
authors.forename: Simon
authors.initials: S
authors.lastname: Swift
authors.affiliation: Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand.|School of Optometry and Vision Science, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand.
authors.forename: Alex
authors.initials: A
authors.lastname: Petty
authors.affiliation: Department of Ophthalmology, New Zealand National Eye Centre, The University of Auckland, Auckland, New Zealand.
authors.forename: Jennifer P
authors.initials: JP
authors.lastname: Craig
mesh_terms: D000328:Adult; D001419:Bacteria / Q000302:isolation & purification*; D001762:Blepharitis / Q000453:epidemiology / Q000382:microbiology*; D003430:Cross-Sectional Studies; D015818:Eye Infections, Bacterial / Q000382:microbiology*; D005141:Eyelid Diseases; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008537:Meibomian Glands / Q000382:microbiology*; D064307:Microbiota; D009520:New Zealand / Q000453:epidemiology; D011446:Prospective Studies
keywords: bacteria; blepharitis; dry eye; meibomian gland dysfunction; microbiome