Occupational radiation exposure and glaucoma and macular degeneration in the US radiologic technologists

Mark P Little,Steven L Simon,Craig Meyer,Elizabeth K Cahoon,Raquel Velazquez-Kronen,Martha S Linet,David Borrego,Nobuyuki Hamada,Marie-Odile Bernier,Jeremy S Miller,Michele M Doody,Cari M Kitahara,Dale L Preston,Bruce H Alexander

doi:10.1038/s41598-018-28620-6

Abstract

There are well-documented associations of glaucoma with high-dose radiation exposure, but only a single study suggesting risk of glaucoma, and less conclusively macular degeneration, associated with moderate-dose exposure. We assessed risk of glaucoma and macular degeneration associated with occupational eye-lens radiation dose, using participants from the US Radiologic Technologists Study, followed from the date of surveys in 1994–1998, 2003–2005 to the earliest of diagnosis of glaucoma or macular degeneration, cancer other than non-melanoma skin cancer, or date of last survey (2012–2014). We excluded those with baseline disease or previous radiotherapy history. Cox proportional hazards models with age as timescale were used. There were 1631 cases of newly self-reported doctor-diagnosed cases of glaucoma and 1331 of macular degeneration among 69,568 and 69,969 eligible subjects, respectively. Estimated mean cumulative eye-lens absorbed dose from occupational radiation exposures was 0.058 Gy. The excess relative risk/Gy for glaucoma was −0.57 (95% CI −1.46, 0.60, p = 0.304) and for macular degeneration was 0.32 (95% CI −0.32, 1.27, p = 0.381), suggesting that there is no appreciable risk for either endpoint associated with low-dose and low dose-rate radiation exposure. Since this is the first examination of glaucoma and macular degeneration associated with low-dose radiation exposure, this result needs to be replicated in other low-dose studies.

Highlights

In 2013, the total economic burden of vision loss and blindness in the US was estimated to be $139 billion, and treatment of eye-related disorders totalled more than $68.8 billion in annual direct medical costs[1]
We found no significant radiation-associated excess risk for glaucoma or macular degeneration in analyses adjusted for other covariates
The study is unusual in that it has a rich set of individual lifestyle and environmental covariate data, some of which were used to adjust baseline risk. Risks for both endpoints were significantly associated with lifestyle and medical risk factors, in particular, diabetes, obesity, and race (Table 1)

Summary

Introduction

In 2013, the total economic burden of vision loss and blindness in the US was estimated to be $139 billion, and treatment of eye-related disorders totalled more than $68.8 billion in annual direct medical costs[1]. Cigarette smoking and genetic risk are the well-established major environmental and lifestyle risk factors associated with macular degeneration[10]; there is some evidence for risks associated with obesity, certain nutritional components (in particular increased total fat) and other factors linked with circulatory disease[11,12,13,14]. Exposure has been found to be correlated with macular degeneration, but the direction of the association is in doubt[15,16]; there is little data, even of this contradictory sort, suggesting a link of solar exposure with glaucoma. There is evidence of association of retinal degeneration with radiation dose in the Japanese atomic-bomb survivors[20], but no association with macular degeneration as such[21]. We analysed glaucoma and macular degeneration in the US Radiologic Technologist (USRT) cohort in relation to cumulative absorbed dose from occupational radiation exposures.

Methods

Results

Conclusion