title: Iodine-131 Therapy and Nasolacrimal Duct Obstructions: What We Know and What We Need to Know.
abstract: OBJECTIVE
  The aims of the current review are to summarize the etiopathogenesis, symptomatology, management, complications, and outcomes of iodine-131-induced nasolacrimal duct obstructions, to propose a screening protocol and elucidate the potential avenues of future research.
  
  
  METHODS
  The authors performed an electronic database (PubMed, MEDLINE, EMBASE, and Cochrane Library) search of all articles published in English on nasolacrimal duct obstructions following radioiodine therapy. These articles were reviewed along with their relevant cross references. Data reviewed included demographics, presentations, investigations, management, complications, and outcomes. In addition, based on relevant unanswered questions and current lacunae in literature, potential avenues for further research have been elucidated.
  
  
  RESULTS
  The frequency of nasolacrimal duct obstruction is reported to range from 2.2% to 18% following I-131 therapy. They are mostly bilateral and noted in patients who receive more than 150 mCi radioiodine. Exact etiopathogenesis is unknown but radiotoxicity to lacrimal sac and nasolacrimal duct is believed to be mediated through a sodium-iodine symporter protein. Although uncommon, it is important to increase awareness among treating physicians and patients receiving radioiodine therapy about the potential side effect of nasolacrimal duct obstruction. Imaging modalities are useful adjuncts in the diagnosis. Dacryocystorhinostomy is the most common modality of management with good outcomes.
  
  
  CONCLUSIONS
  Nasolacrimal duct obstruction following radioiodine treatment is a distinct clinical entity. Increased awareness would facilitate timely diagnosis, management, and an enhanced quality of life for the patients.
authors: The Institute of Dacryology, L.V. Prasad Eye Institute, Hyderabad, India.
authors: Mohammad Javed
authors: MJ
authors: Ali
mesh_terms: D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D007767:Lacrimal Duct Obstruction / Q000532:radiotherapy*; D009301:Nasolacrimal Duct / Q000528:radiation effects*
chemical_list: D007457:Iodine Radioisotopes