title: Nasolacrimal obstruction secondary to I(131) therapy.
abstract: OBJECTIVE
  To report the finding of nasolacrimal drainage system obstruction associated with I(131) therapy for thyroid carcinoma from an updated and expanded cohort.
  
  
  METHODS
  Patients with a history of epithelial derived thyroid carcinoma who had tearing were offered referral for evaluation by an oculoplastic surgeon. Patients underwent nasolacrimal probing and irrigation procedures with localization of their nasolacrimal obstruction. Therapy for the site of obstruction was instituted.
  
  
  RESULTS
  Clinically significant tearing was identified in 26 patients, all of whom had previously undergone I(131) therapy (n = 563). Nineteen patients were evaluated and confirmed to have nasolacrimal drainage system obstruction; 7 have yet to be formally evaluated. Areas of obstruction included nasolacrimal duct, common canaliculus, and, rarely, distal upper and lower canaliculi. Patients were treated with a variety of modalities including silicone intubation, balloon dacryoplasty, dacryocystorhinostomy, and conjunctival dacryocystorhinostomy.
  
  
  CONCLUSIONS
  The use of I(131) for thyroid carcinoma is associated with a 3.4% incidence of documented nasolacrimal drainage obstruction and an overall 4.6% incidence of documented or suspected obstruction. The true incidence may be higher, since - I(131) treated individuals were neither systematically evaluated nor questioned about tearing. It has yet to be established if the obstructions result from local toxicity caused by the passive flow of radioactive iodine containing tears through these tissues or the active uptake and concentration of I(131) in lacrimal drainage system tissues through the sodium/iodide supporter.
authors.affiliation: Department of Ophthalmology, Division of Oculoplastic Surgery, The Ohio State University, Columbus, Ohio, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Burns
authors.forename: K E
authors.initials: KE
authors.lastname: Morgenstern
authors.forename: K V
authors.initials: KV
authors.lastname: Cahill
authors.forename: J A
authors.initials: JA
authors.lastname: Foster
authors.forename: S M
authors.initials: SM
authors.lastname: Jhiang
authors.forename: R T
authors.initials: RT
authors.lastname: Kloos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002404:Catheterization; D003608:Dacryocystorhinostomy; D005260:Female; D006801:Humans; D007440:Intubation / Q000379:methods; D007457:Iodine Radioisotopes / Q000009:adverse effects; D007767:Lacrimal Duct Obstruction / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009301:Nasolacrimal Duct / Q000528:radiation effects* / Q000601:surgery; D011832:Radiation Injuries / Q000209:etiology* / Q000601:surgery; D012826:Silicone Elastomers; D013964:Thyroid Neoplasms / Q000532:radiotherapy
chemical_list: D007457:Iodine Radioisotopes; D012826:Silicone Elastomers