title: Corneal Epithelial Immune Dendritic Cell Alterations in Subtypes of Dry Eye Disease: A Pilot In Vivo Confocal Microscopic Study.
abstract: OBJECTIVE
  To evaluate density and morphology of corneal epithelial immune dendritic cells (DCs) in different subtypes of dry eye disease (DED) using in vivo confocal microscopy (IVCM).
  
  
  METHODS
  This retrospective study included 59 eyes of 37 patients with DED and 40 eyes of 20 age-matched healthy controls. Based on clinical tests, eyes with DED were categorized into two subtypes: aqueous-deficient (n = 35) and evaporative (n = 24). For all subjects, images of laser scanning in vivo confocal microscopy (IVCM) of the central cornea were analyzed for DC density and DC morphology (DC size, number of dendrites, and DC field). These DC parameters were compared among all dry eye and control groups.
  
  
  RESULTS
  Compared with the controls, patients with DED had significantly higher DC density, larger DC size, higher number of dendrites, and larger DC field (all P < 0.001). Comparison between aqueous-deficient and evaporative subtypes demonstrated that DC density was significantly higher in aqueous-deficient subtype (189.8 ± 36.9 vs. 58.9 ± 9.4 cells/mm2, P = 0.001). However, there were no significant differences in morphologic parameters between DED subtypes. When aqueous-deficient DED with underlying systemic immune disease (Sjögren's syndrome and graft versus host disease) were compared with nonimmune conditions, the immunologic subgroup showed significantly higher DC density, DC size, and number of dendrites (all P < 0.05).
  
  
  CONCLUSIONS
  Corneal IVCM demonstrated differential changes in DC density and morphologic DC parameters between subtypes of DED. These changes, which reflect the degree of immune activation and inflammation in DED, can be used for clinical practice and endpoints in clinical trials.
authors.affiliation: Ocular Surface Imaging Center, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Kheirkhah
authors.affiliation: Ocular Surface Imaging Center, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Raheleh
authors.initials: R
authors.lastname: Rahimi Darabad
authors.affiliation: Ocular Surface Imaging Center, Harvard Medical School, Boston, Massachusetts, United States 2Department of Ophthalmology, Pontificia Universidad de Chile, Santiago, Chile.
authors.forename: Andrea
authors.initials: A
authors.lastname: Cruzat
authors.affiliation: Ocular Surface Imaging Center, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Amir Reza
authors.initials: AR
authors.lastname: Hajrasouliha
authors.affiliation: Ocular Surface Imaging Center, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Deborah
authors.initials: D
authors.lastname: Witkin
authors.affiliation: Ocular Surface Imaging Center, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Nadia
authors.initials: N
authors.lastname: Wong
authors.affiliation: Cornea Service, Massachusetts Eye & Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States.
authors.forename: Reza
authors.initials: R
authors.lastname: Dana
authors.affiliation: Ocular Surface Imaging Center, Harvard Medical School, Boston, Massachusetts, United States 2Cornea Service, Massachusetts Eye & Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States 3Boston Image Reading.
authors.forename: Pedram
authors.initials: P
authors.lastname: Hamrah
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002452:Cell Count; D003430:Cross-Sectional Studies; D003713:Dendritic Cells / Q000276:immunology / Q000473:pathology*; D015352:Dry Eye Syndromes / Q000276:immunology / Q000473:pathology*; D019573:Epithelium, Corneal / Q000276:immunology / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007111:Immunity, Cellular; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D008875:Middle Aged; D010865:Pilot Projects; D012189:Retrospective Studies; D012720:Severity of Illness Index; D055815:Young Adult