Occupational radiation exposure to the lens of the eye in interventional radiology

Introduction: Cataract formation is a tissue reaction effected by radiation exposure. The purpose of this study was to evaluate the occupational exposure to the lens of the eye of interventional radiologists (IR's) and interventional radiology staff, with and without lead glasses.

Methods: Ethical approval was provided by the hospital research and ethics committee. A prospective cohort study was performed over 1 year, doses recorded, lifetime dose (estimated at working 5 days in angiography, for 30 years) was estimated and dose compared to current guidelines. Thermoluminescent dosimeters (TLDs; Landauer, Glenwood, USA) Hp(3) were placed on both the exterior and interior side of the personal lead glasses worn by three interventional radiologists and two radiographers. They were monitored during all procedures performed within 1 year. Lead glasses (AttenuTech^® Microlite^® , Florida, USA) with specifications were 0.75 mm lead equivalent front shield, and Side shield 0.3 mm Pb equivalent. A control TLD was placed in the storage location of the lead glasses when not in use. Yearly dose was measured and lifetime dose was calculated from the data obtained. Calculation of dose received per day(s) spent performing procedures for both annual and lifetime exposure was performed. In addition a record of occurrence of splashes on glasses was made after each case.

Results: Eye doses without protection were double the recommended limits for both annual and lifetime dose. For interventional radiologists working between 3 and 4 or more days in the lab per week, annual dose thresholds would be exceeded (20 mSv/year averaged over 5 years, no more than 50 mSv in 1 year). If interventional radiologists worked between 3 and 4 or more days in the lab, lifetime dose thresholds would be exceeded (500 mSv lifetime dose). Lead glasses reduced radiation exposure by an average of 79%. If lead glasses were worn no interventional radiologists would exceed annual or lifetime dose thresholds to the eyes even if working 5 days per week as the primary operator. Radiographers would not exceed annual or lifetime dose thresholds even without lead glasses. Splash incidents occurred for all interventional radiologists and one radiographer.

Conclusion: The use of lead glasses even in this small study resulted in a decreased dose of radiation to the lens of the eye. Regular use of radiation protection eyewear will reduce eye dose for primary proceduralists to well below yearly and lifetime thresholds.