Radioactive contamination of contact lenses during radioiodine therapy

Although the secretion of radioiodine in tears is not unexpected, there are only few investigations in that field. We report the measurement of I-131 in disposable contact lenses for daily use during radioiodine treatment. Af ter administration of 740 MBq I-131 all contact lenses of a 59-year-old fem ale used the day before and 5 days after radioiodine therapy were collected and measured in a gamma counter. Activities of 124 Bq (right) and 139 Bq ( left) were measured in the contact lenses used during the first day after a dministration of radioiodine. The activity in the contact lenses of the fol lowing days was significantly lower. An initial dose rate of approximately 0.31 mu Sv.h(-1) was caused by the radioactivity resulting in a total dose of 13 mu Sv to the patient's eye lens. That dose is negligible compared to the dose caused by the incorporated radioactivity. ((C) 2000 Lippincott Wil liams & Wilkins).