Radiation Cataract Risk in Interventional Cardiology Personnel

Abstract

The lens of the eye is one of the most radiosensitive tissues in the body, and exposure of the lens to ionizing radiation can cause cataract. Cumulative X-ray doses to the lenses of interventional cardiologists and associated staff can be high. The International Commission on Radiological Protection recently noted considerable uncertainty concerning radiation risk to the lens. This study evaluated risk of radiation cataract after occupational exposure in interventional cardiology personnel. Comprehensive dilated slit-lamp examinations were performed in interventional cardiologists, associated workers and controls. Radiation exposures were estimated using experimental data from catheterization laboratories and answers to detailed questionnaires. A total of 116 exposed and 93 similarly aged nonexposed individuals were examined. The relative risk of posterior subcapsular opacities in interventional cardiologists compared to unexposed controls was 3.2 (38% compared to 12%; P < 0.005). A total of 21% of nurses and technicians had radiation-associated posterior lens changes typically associated with ionizing radiation exposure. Cumulative median values of lens doses were estimated at 6.0 Sv for cardiologists and 1.5 Sv for associated medical personnel. A significantly elevated incidence of radiation-associated lens changes in interventional cardiology workers indicates there is an urgent need to educate these professionals in radiation protection to reduce the likelihood of cataract.

Ionizing radiation exposure in interventional cardiology: current radiation protection practice of invasive cardiology operators in Lithuania

“…Professional cataract is a well-known problem in invasive cardiology workers and is distinguished from naturally occurring cataract forms as it occurs in the posterior pole of the lens [33][34][35]. Since recognition of this issue, the permitted dose to the lens of the eye had been dramatically reduced from 150 mSv yr −1 to 20 mSv yr −1 in 2011 [36].…”

Ionizing Radiation as a Risk Factor for Cataract: What about Low-Dose Effects?

“…In Day's study [16], reliability of the lesions assessment was not very good between ophthalmologists despite examiner training and other quality-control measures, with strong evidence for a statistically significant incremental linear learning effect across the 3 field sites leading to an under-assessment during the initial phase of the field research. Among interventional cardiologists, only posterior subcapsular lens opacities was previously investigated, which may appear as a limit [29,30]. The use of standard classification as LOCS 2 or 3 for eye lens classification, as it was done in the NASCA study [25] and many others, is nevertheless a good approach to investigate the impact of ionizing radiation on different types of cataracts.…”

“…In Worgul et al [12], uncertainties on the estimated doses remain an important limit of the paper, even if the impact of dose uncertainty on the results was assessed. In medical staff studies, doses were either based on passive dosimetry (chest badge) [28] which may not be a good index for eye lens exposure, especially when radiation protection eyewear is used, or based on description of workload in terms of procedures and mean doses per procedure, which may suffer from memory bias [29][30][31]. However, radiation-induced cataracts have been globally observed in different exposed populations at lower doses (< 1 Gy) than the expected dose threshold of 2 Gy.…”

“…Vano et al [29] published a study including 58 interventional PSC: posterior subcapsular cataract; CC: Cortical cataract; NC: Nuclear cataract; E: exposed; NE: Not exposed; IC:Interventional cardiologists cardiologists (mean age=46 years), 58 nurses and technicians (mean age=38 years) from Bogota and Montevideo and 93 unexposed controls (mean age=41 years). All participants had an eye examination during a cardiology conference and Merriam-Focht classification was used to grade posterior subcapsular lens opacities.…”

Use of personal radiation protection tools and individual dosimetric monitoring in a sample of interventional cardiologists in France, 2005–2009

“…The annual effective dose limit for ICs, as for all radiation workers, is 20 mSv per year. Moreover, it has previously been observed that these physicians' eyes are particularly exposed , and they may develop radiation-induced cataracts when radiation protection measures are not used (Ciraj-Bjelac et al, 2010;Vano et al, 2010;Jacob et al, 2012). In April 2011, on the basis of epidemiological and biological studies, the International sophie.jacob@irsn.fr Commission on Radiological Protection (ICRP) revised its lifetime eye dose threshold for cataract induction downwards from 2 Gy to 0.5 Gy, and the annual occupational eye dose limit from 150 mSv to 20 mSv per year (ICRP, 2009(ICRP, , 2011.…”