Abstract
Purpose: :
The lens is one of the most radiosensitive tissues. Exposure to ionizing radiation causes characteristic, dose related progressive lens changes leading to cataract. There is considerable uncertainty concerning radiation risk to the lens. Under typical working conditions, cumulative dose to the lenses of interventional cardiologists and staff may be high. This study seeks to determine the risk of radiation cataract following occupational x-ray exposure in interventional cardiology personnel.
Methods: :
Comprehensive, dilated slit lamp exams were performed in interventional cardiologists (IC), associated medical workers and unexposed controls. Subjects were examined at cardiology Congresses in Colombia, Uruguay and Malaysia under the auspices of the International Atomic Energy Agency and regional cardiology societies. Occupational exposure was determined using experimental data from catheterization suites and answers to detailed questionnaires.
Results: :
116 exposed and 93 unexposed professionals of similar ages were examined in the combined Uruguay/Colombia Latin American cohort. Posterior subcapsular opacities typically associated with ionizing radiation exposure were found in 38% of IC (46±8 yrs) as compared to 12% of controls (41±10 yrs) (p < 0.005). Merriam-Focht scores ranging from 0.5-2.0 were noted. 21% of nurses and technicians (38 ±7 yrs) had radiation associated lens changes, predominately of lesser severity. Cumulative median lens doses were estimated at 6.0 Sv for IC and 1.5 Sv for associated personnel. Most individuals reported no consistent use of eye protection. In the Asian cohort, 125 persons (56 IC’s, 14 nurses/technicans and 55 unexposed controls) were examined. Posterior subcapsular opacities were observed in 52% of IC’s (41±8 yrs) (p<0.05), 43% of nurses/technical staff (38±11 yrs) and 21% of unexposed age-matched controls (43±9 yrs).
Conclusions: :
This survey is the first to demonstrate a significantly elevated prevalence of radiation associated lens opacities in IC as compared to similarly aged unexposed controls. Increased prevalence of lens opacities in associated nurses and technicians suggests ocular risk in these workers may also be underestimated. The findings indicate an urgent need to educate IC professionals about ocular protection to reduce the likelihood of cataract.
Keywords: cataract • clinical (human) or epidemiologic studies: risk factor assessment • clinical (human) or epidemiologic studies: prevalence/incidence