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).