title: Long-term impairment of the lacrimal glands after radioiodine therapy: a cross-sectional study.
abstract: Impairment of the lacrimal glands after external radiation has been well documented, but there are only a few reports on the effects of radioiodine therapy on the lacrimal glands. Long-term effects of high-dose radioiodine therapy on tear secretion have not previously been studied. We investigated 175 eyes of 88 patients with a history of radioiodine therapy for thyroid carcinoma (68 females, 20 males; mean age 55+/-16 years, range 17-81 years) and compared them with a sex- and age-matched control group ( n=39). All patients had been given at least 2.96 GBq iodine-131 (maximal administered activity 22.3 GBq (131)I). An ophthalmological investigation was performed 64+/-71 months (range 3-317 months) after initial radioiodine therapy by a single ophthalmologist. Lacrimal gland function was evaluated with three different function tests. External eye morphology was considered, and detailed ophthalmological history-taking was performed. Patients with factors known to affect lacrimal gland function (contact lenses, autoimmune disorders, history of additional radiation exposure) were excluded from the study. A total of 81 patients (92%) had at least one abnormal function test indicating impaired lacrimal gland function. Schirmer's tear test was decreased (<10 mm/5 min) in 47 of the 88 patients and definitely abnormal (<5 mm/5 min) in 35 patients. A tear film break-up time of <10 s was found in 78 patients, and 62 patients had a definitely abnormal break-up time of <5 s. The lacrimal lipid layer was impaired in 43 patients. The function tests were all significantly altered in the study group as compared with the controls ( P<0.005, P<0.001, P<0.001, respectively). Both subjective symptoms of dry eye ( P<0.01) and changes in the external eye morphology ( P<0.001) were significantly more prevalent in the study group. Our findings suggest that in the majority of patients, lacrimal gland function may be permanently impaired after high-dose radioiodine therapy. All three layers of the tear film are involved and there is a pronounced long-term effect on the tear film stability.
authors.affiliation: Department of Nuclear Medicine, University of Vienna, Währinger Gürtel 18-20, 1090 Wien, Austria. georg.zettinig@akh-wien.ac.at
authors.forename: Georg
authors.initials: G
authors.lastname: Zettinig
authors.forename: Georg
authors.initials: G
authors.lastname: Hanselmayer
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Fueger
authors.forename: Andrea
authors.initials: A
authors.lastname: Hofmann
authors.forename: Christian
authors.initials: C
authors.lastname: Pirich
authors.forename: Johannes
authors.initials: J
authors.lastname: Nepp
authors.forename: Robert
authors.initials: R
authors.lastname: Dudczak
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D015352:Dry Eye Syndromes / Q000175:diagnosis / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D007765:Lacrimal Apparatus / Q000293:injuries / Q000378:metabolism / Q000503:physiopathology* / Q000528:radiation effects*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000532:radiotherapy*
chemical_list: D007457:Iodine Radioisotopes