title: Lacrimal System Obstruction After Radioiodine Therapy in Differentiated Thyroid Carcinomas: A Prospective Comparative Study.
abstract: Radioiodine therapy (RIT) is an established treatment for differentiated thyroid carcinomas, and is widely used throughout the world, given the increasing incidence of this malignancy. Although serious adverse effects are infrequent, complications such as dry mouth, sialadenitis, and dysphagia have been described. The involvement of the eyes and accessory visual structures is not commonly discussed, despite dry eye, keratoconjunctivitis, and lacrimal system obstruction (LSO) being reported, especially after high cumulative doses of radiopharmaceuticals. The incidence of LSO is not well established.
  
  
  
  The aim of this study was to determine the frequency of LSO in patients undergoing RIT at 2, 4, 6, and 12 months after treatment.
  
  
  
  Patients with differentiated thyroid carcinoma undergoing (group 1) and not undergoing (group 2) RIT were evaluated in the preoperative and postoperative periods and 2, 4, 6, and 12 months post surgery or post RIT. Patients underwent tear film evaluation and lacrimal system probing and irrigation.
  
  
  
  Group 1 (n = 44; 88 eyes) contained three patients (four eyes) with LSO, corresponding to an incidence of 4.55% (four events in 88 eyes) or 6.8% (three cases in 44 patients). Group 2 (n = 43; 86 eyes) did not present any cases of LSO.
  
  
  
  In this study, an active prospective investigation allowed LSO detection during the first six months after RIT. This finding demonstrates the importance of making this association clear to patients and health professionals, with a view to early diagnosis, appropriate treatment, and preventing LSO-related complications.
authors: Department of Ophthalmology, Clinical Hospital, School of Medicine, University of São Paulo (Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo-HCFMUSP) , São Paulo, Brazil .
authors: Fabricio Lopes
authors: FL
authors: da Fonseca
authors: Department of Ophthalmology, Clinical Hospital, School of Medicine, University of São Paulo (Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo-HCFMUSP) , São Paulo, Brazil .
authors: Patricia Kazue
authors: PK
authors: Yamanaka
authors: Department of Ophthalmology, Clinical Hospital, School of Medicine, University of São Paulo (Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo-HCFMUSP) , São Paulo, Brazil .
authors: Juliana Mika
authors: JM
authors: Kato
authors: Department of Ophthalmology, Clinical Hospital, School of Medicine, University of São Paulo (Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo-HCFMUSP) , São Paulo, Brazil .
authors: Suzana
authors: S
authors: Matayoshi
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D007767:Lacrimal Duct Obstruction / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013964:Thyroid Neoplasms / Q000532:radiotherapy*; D016896:Treatment Outcome
chemical_list: D007457:Iodine Radioisotopes
keywords: iodine radioisotopes; lacrimal apparatus diseases; nasolacrimal duct obstruction; nasolacrimal duct/radiation effects; thyroid gland cancer/radiotherapy