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

Abstract

Lens opacities are potential serious consequences of eye exposure to ionizing radiation. Several studies have shown with certainty that radiation cataractogenesis has a much lower threshold than the old radiation protection guidelines of the International Commission on Radiological Protection (ICRP), specifically 2 Gy (Grays) for acute exposure and 5 Gy for fractioned exposure. In April 2011, the ICRP revised its eye dose threshold for cataract induction downwards from 2 Gy to 0.5 Gy, and the occupational annual dose limit from 150 mSv to 20 mSv/year. Moreover, based on previous studies the traditional view that posterior subcapsular opacities are the only signature form of radiation cataract may have to be broadened to cortical cataracts.\rWe present the most recent results on lens opacities and early stages of cataract that were observed for ionizing radiation doses below 1 Gy and which have led the ICRP to decrease the eye lens dose threshold.