title: Role of Thyroxine in the Development of Keratoconus.
abstract: OBJECTIVE
  Keratoconus (KC) is a corneal ectasia whose pathophysiology is still mostly unknown. We investigated whether thyroid gland dysfunction (TGD) is associated with the development of KC.
  
  
  METHODS
  We first conducted an epidemiological study, examining the prevalence of TGD among patients with KC. Then, we compared tear thyroxine (T4) in TGD and immunohistochemical staining of its receptors (T4Rs) between patients with KC and controls. The significance of T4 for corneal metabolism was studied in organotypic tissue cultures from monkey corneas.
  
  
  RESULTS
  We found that TGD prevalence among patients with KC is 13.6%, which is higher than its prevalence in the general population (about 2%). Tear T4 was higher in KC, and keratocyte T4Rs were elevated in KC compared with controls. Furthermore, core proteins such as collagen and cytokeratins were equally altered both in KC and in the cultured corneas substituted with T4.
  
  
  CONCLUSIONS
  Our data implicate a crucial role of T4 in KC pathophysiology, which is most likely mediated by T4Rs.
authors: *Institute of Experimental Ophthalmology, School of Medicine, University of Münster, Münster, Germany; †Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA; ‡Institute of Regenerative Medicine, University of Münster, Münster, Germany; and §Department of Ophthalmology, Saarland University Medical Center UKS, Homburg, Germany.
authors: Solon
authors: S
authors: Thanos
authors: Patrick
authors: P
authors: Oellers
authors: Melissa
authors: M
authors: Meyer Zu Hörste
authors: Verena
authors: V
authors: Prokosch
authors: Stefan
authors: S
authors: Schlatt
authors: Berthold
authors: B
authors: Seitz
authors: Zisis
authors: Z
authors: Gatzioufas
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D018929:Cell Culture Techniques; D060527:Corneal Keratocytes / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D016021:Epidemiologic Studies; D005136:Eye Proteins / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007640:Keratoconus / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology*; D015948:Keratoplasty, Penetrating; D008252:Macaca fascicularis; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011988:Receptors, Thyroid Hormone / Q000378:metabolism; D013666:Tears / Q000378:metabolism; D013959:Thyroid Diseases / Q000453:epidemiology / Q000378:metabolism / Q000503:physiopathology*; D013972:Thyrotropin / Q000378:metabolism; D013974:Thyroxine / Q000502:physiology*; D055815:Young Adult
chemical_list: D005136:Eye Proteins; D011988:Receptors, Thyroid Hormone; C042434:tear proteins; D013972:Thyrotropin; D013974:Thyroxine