Lacrimal system pathology in patients with malignant thyroid tumors after radioactive iodine therapy, and its correction methods

Introduction. Radioactive iodine therapy after thyroidectomy is the standard of differentiated thyroid cancer treatment in the modern world. Main dose-dependent side effects described in the literature include: sialadenitis, xerostomia, taste and/or odor loss, swelling of surrounding tissues. Ophthalmic complications are rarely reported.

Aim. To assess the lacrimal system condition in patients after radioactive iodine therapy for thyroid cancer.

Material and methods. The study included 17 patients (34 eyes). There were female patients aged 19 to 43 years (mean age was 31 years) who underwent a course of radioactive iodine therapy for thyroid cancer. All of them complained of periodic or constant tearing in the period from 2 months to 1 year after therapy course. In four patients, there was a permanent or periodic mucopurulent discharge when pressing on the lacrimal sac area. All patients underwent a standard ophthalmological examination, including visual acuity testing, anterior segment biomicroscopy, ophthalmoscopy, and tear production tests. Dye disappearance test, Jones I and II tests, lacrimal pathways irrigation, and, if necessary, cone-ray computer tomography with preliminary lacrimal pathways contrasting were performed to evaluate the tear outflow abnormalities.

Results. Tear production disorders were detected in 20 eyes (58.8%) (among them, moderate dry eye syndrome was diagnosed in 3 cases); tear outflow pathology was revealed in 14 eyes (41.2%) (namely naso-lacrimal duct obstruction and stenosis, and chronic purulent dacryocystitis). For patients with tear production pathology artificial tears were prescribed, and endoscopic endonasal dacryocystorhinostomy was performed in cases of tear outflow disturbances.

Conclusion. The use of radioactive iodine in doses exceeding 80 mCi leads to the development of lacrimal system pathology: dry eye syndrome of various severity, and tear outflow disorders. Lacrimal system pathology significantly worsens the patient's quality of life, and the prophylaxis of these diseases before the radioactive iodine therapy course remains the imminent key problem.