title: Infrared imaging of meibomian gland structure using a novel keratograph.
abstract: OBJECTIVE
  To examine the ability of a novel non-contact device (Keratograph 4) to image the meibomian gland (MG) structures and their morphological changes in the upper and lower eyelids.
  
  
  METHODS
  Thirty-seven participants (mean age 57.8 ± 8.5 years; 3 males and 34 females) completed the Ocular Surface Disease Index questionnaire to assess dryness symptoms. Meibum secretion quality score, number of blocked gland orifices, and meibum expressibility scores were assessed. The lower lid (LL) and upper lid (UL) of all subjects were everted and images of the MGs were taken using the Keratograph 4 (OCULUS). A MG dropout score (MGDS) due to complete or partial gland loss of both lids was obtained using a subjective 4-grade scoring system, and digital analysis of the images using ImageJ was performed. Presence of tortuosity and visible acinar changes of the MGs were also noted.
  
  
  RESULTS
  MGDS for both lids was significantly positively correlated with the Ocular Surface Disease Index score (r = 0.51; p < 0.05). The MGDS determined using the digital grading was also significantly positively correlated (UL: r = 0.68, p < 0.05; LL: r = 0.42, p < 0.05). The sum of the MGDS for both lids using the subjective grading scale was significantly different between the non-MGD and MGD group (1.3 ± 1.0 vs. 3.1 ± 1.1; p = 0.0004). MGDS assessment using the digital grading was significantly different between non-MGD (UL = 6%, LL = 8%) and MGD group (UL = 32%, LL = 42%; p = 0.001). Tortuous MG was observed only on the UL in 6% of the participants. Visible acinar changes were noted in 40% of the study participants.
  
  
  CONCLUSIONS
  Infrared meibography is now possible in a clinical setting using commercially available devices, and meibography can help determine differences in MG structure in subjects symptomatic of dry eye.
authors.affiliation: Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada. s2sriniv@uwaterloo.ca
authors.forename: Sruthi
authors.initials: S
authors.lastname: Srinivasan
authors.forename: Kara
authors.initials: K
authors.lastname: Menzies
authors.forename: Luigina
authors.initials: L
authors.lastname: Sorbara
authors.forename: Lyndon
authors.initials: L
authors.lastname: Jones
mesh_terms: D003315:Cornea / Q000378:metabolism / Q000473:pathology*; D019781:Corneal Topography / Q000379:methods*; D003941:Diagnostic Techniques, Ophthalmological; D015352:Dry Eye Syndromes / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D006801:Humans; D007259:Infrared Rays; D008297:Male; D008537:Meibomian Glands / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013666:Tears / Q000378:metabolism*