title: Thyroid-associated ophthalmopathy after treatment for Graves' hyperthyroidism with antithyroid drugs or iodine-131.
abstract: BACKGROUND
  Previous randomized trials have suggested an association between radioiodine treatment for Graves' hyperthyroidism and thyroid-associated ophthalmopathy (TAO).
  
  
  OBJECTIVE
  The aim of the study was to compare the occurrence of worsening or development of TAO in patients who were treated with radioiodine or antithyroid drugs.
  
  
  METHODS
  We conducted a randomized trial (TT 96) with a follow-up of 4 yr. PATIENTS, SETTING, AND INTERVENTION: Patients with a recent diagnosis of Graves' hyperthyroidism were randomized to treatment with iodine-131 (163 patients) or 18 months of medical treatment (150 patients). Early substitution with T(4) was given in both groups.
  
  
  METHODS
  Worsening or development of TAO was significantly more common in the iodine-131 treatment group (63 patients; 38.7%) compared with the medical treatment group (32 patients; 21.3%) (P < 0.001).
  
  
  RESULTS
  The risk for de novo development of TAO was greater in patients treated with iodine-131 (53 patients) than with medical treatment (23 patients). However, worsening of TAO in the 41 patients who had ophthalmopathy already before the start of treatment was not more common in the radioiodine group (10 patients) than in the medical group (nine patients). Smoking was shown to influence the risk of worsening or development of TAO, and smokers treated with radioiodine had the overall highest risk for TAO. However, in the group of smokers, worsening or development of TAO was not significantly associated with the choice of treatment for hyperthyroidism.
  
  
  CONCLUSIONS
  Radioiodine treatment is a significant risk factor for development of TAO in Graves' hyperthyroidism. Smokers run the highest risk for worsening or development of TAO irrespective of treatment modality.
authors.affiliation: Department of Clinical Neurosciences, Karolinska Institute, St. Erik Eye Hospital, SE-11282, Stockholm, Sweden. frank.traisk@sankterik.se
authors.forename: Frank
authors.initials: F
authors.lastname: Träisk
authors.forename: Leif
authors.initials: L
authors.lastname: Tallstedt
authors.forename: Mirna
authors.initials: M
authors.lastname: Abraham-Nordling
authors.forename: Tommy
authors.initials: T
authors.lastname: Andersson
authors.forename: Gertrud
authors.initials: G
authors.lastname: Berg
authors.forename: Jan
authors.initials: J
authors.lastname: Calissendorff
authors.forename: Bengt
authors.initials: B
authors.lastname: Hallengren
authors.forename: Pavo
authors.initials: P
authors.lastname: Hedner
authors.forename: Mikael
authors.initials: M
authors.lastname: Lantz
authors.forename: Ernst
authors.initials: E
authors.lastname: Nyström
authors.forename: Vesna
authors.initials: V
authors.lastname: Ponjavic
authors.forename: Adam
authors.initials: A
authors.lastname: Taube
authors.forename: Ove
authors.initials: O
authors.lastname: Törring
authors.forename: Göran
authors.initials: G
authors.lastname: Wallin
authors.forename: Peter
authors.initials: P
authors.lastname: Asman
authors.forename: Göran
authors.initials: G
authors.lastname: Lundell
mesh_terms: D000328:Adult; D000368:Aged; D013956:Antithyroid Agents / Q000627:therapeutic use*; D018450:Disease Progression; D005260:Female; D049970:Graves Ophthalmopathy / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology; D006801:Humans; D006980:Hyperthyroidism / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy*; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D013972:Thyrotropin / Q000097:blood
chemical_list: D013956:Antithyroid Agents; D007457:Iodine Radioisotopes; D013972:Thyrotropin