Lenticular opacities in individuals exposed to ionizing radiation in infancy.

Development of lens opacities and the measures taken to avoid them have clinical relevance in the fields of oncology, radiotherapy and radiation protection. The aim of this study was to correlate the prevalence of lenticular opacities in individuals exposed to ionizing radiation in childhood with radiation dose and other possible risk factors. Between 1920 and 1959, about 16,500 children (age <18 months) with skin hemangiomas were referred to Radiumhemmet, Karolinska University Hospital, 89% of whom were treated with radiotherapy. A total of 484 exposed individuals and 89 nonexposed controls participated in an ophthalmological examination. Lens opacities were found in 357 (37%) of the 953 lenses examined in the exposed persons. In contrast, lens opacities were observed in only 35 (20%) of the 178 lenses examined in the nonexposed control individuals. It is concluded that the increased prevalence of cortical and posterior subcapsular opacities is related to previous radiotherapy. Age at examination was the strongest modifier of risk. Children exposed to a lenticular dose of 1 Gy had a 50% increased risk (odds ratio 1.50; 95% confidence interval 1.10-2.05) of developing a posterior subcapsular opacity and a 35% increased risk of a cortical opacity (odds ratio 1.35; 95% confidence interval 1. 07- 1.69).