The impact of various protective tools on the dose reduction in the eye lens in an interventional cardiology—clinical study

The aim of the study was to check, in clinical practice, the potential for the dose reduction of lead eyewear and a ceiling-suspended shield used to protect the eye lens of physicians working in interventional cardiology. To this end, for the lead eyewear, the dose reduction factors were derived to correct the readings from a dosimeter used routinely outside the glasses. Four types of lead eyewear with attached loose thermoluminescent dosimeters and EYE-D dosimeters were worn by physicians in two clinical centres, for two-month periods, during coronary angiography (CA), percutaneous coronary intervention (PCI), and pacemaker procedures. In order to analyse, separately, how a ceiling-suspended lead screen absorbs the scattered radiation, a series of measurements was carried out during single CA/PCI procedures performed with and without the protection. The lead eyewear may reduce the doses to the eye closest to the x-ray tube by a factor between 1.1 and 3.4, depending on its model and the physician's position. The effectiveness of the eyewear may, however, vary—even for the same model and physician—almost twofold between different working periods. The ceiling-suspended shield decreases the doses in clinical practice by a factor of 2.3. The annual eye lens doses without the eyewear estimated from routine measurements are high—above or close to the new eye lens dose limit established by the recent EU Basic Safety Standards, even though the ceiling-suspended shield was used. Therefore, to comply with the new dose limit that is set in the Directive, protection of the eyes of physicians with high workloads might require the use of both the eyewear and the ceiling-suspended shield. (paper)