title: Extraorbital lacrimal gland excision: a reproducible model of severe aqueous tear-deficient dry eye disease.
abstract: OBJECTIVE
  The aim of this study was to establish and characterize extraorbital lacrimal gland excision (LGE) as a model of aqueous tear-deficient dry eye disease in mice.
  
  
  METHODS
  Female C57BL/6 mice at 6 to 8 weeks of age were randomized to extraorbital LGE, sham surgery, or scopolamine groups. Mice that underwent extraorbital LGE or sham surgery were housed in the standard vivarium. Scopolamine-treated mice were housed in a controlled environment chamber that allowed for the continuous regulation of airflow (15 L/min), relative humidity (30%), and temperature (21-23°C). Clinical disease severity was assessed over the course of 14 days using the phenol red thread test and corneal fluorescein staining. Real-time polymerase chain reaction was performed to assess corneal mRNA expression of interleukin 1β, tumor necrosis factor α, and matrix metalloproteinase 9. Flow cytometry was used to assess T helper cell frequencies in the conjunctivae and draining lymph nodes.
  
  
  RESULTS
  Extraorbital LGE markedly reduced aqueous tear secretion as compared with the sham procedure and induced a more consistent decrease in aqueous tear secretion than was observed in mice that received scopolamine while housed in the controlled environment chamber. Extraorbital LGE significantly increased corneal fluorescein staining scores as compared with those of both the sham surgery and scopolamine-treated groups. Extraorbital LGE significantly increased the corneal expression of interleukin 1β, tumor necrosis factor α, and matrix metalloproteinase 9. Further, extraorbital LGE increased T helper 17-cell frequencies in the conjunctivae and draining lymph nodes.
  
  
  CONCLUSIONS
  Extraorbital LGE induces aqueous tear-deficient dry eye disease in mice as evidenced by decreased aqueous tear secretion, increased corneal epitheliopathy, and induced ocular surface inflammation and immunity.
authors.affiliation: Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA.
authors.forename: William
authors.initials: W
authors.lastname: Stevenson
authors.forename: Yihe
authors.initials: Y
authors.lastname: Chen
authors.forename: Sang-Mok
authors.initials: SM
authors.lastname: Lee
authors.forename: Hyun Soo
authors.initials: HS
authors.lastname: Lee
authors.forename: Jing
authors.initials: J
authors.lastname: Hua
authors.forename: Thomas
authors.initials: T
authors.lastname: Dohlman
authors.forename: Tina
authors.initials: T
authors.lastname: Shiang
authors.forename: Reza
authors.initials: R
authors.lastname: Dana
mesh_terms: D000818:Animals; D001082:Aqueous Humor / Q000378:metabolism*; D003228:Conjunctiva / Q000166:cytology; D004195:Disease Models, Animal; D005260:Female; D005434:Flow Cytometry; D015590:Fluorophotometry; D053583:Interleukin-1beta / Q000235:genetics; D007638:Keratoconjunctivitis Sicca / Q000209:etiology* / Q000378:metabolism; D007765:Lacrimal Apparatus / Q000601:surgery*; D008198:Lymph Nodes / Q000166:cytology; D020780:Matrix Metalloproteinase 9 / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D013666:Tears / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D053583:Interleukin-1beta; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse