{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,31]],"date-time":"2026-10-31T05:32:31Z","timestamp":1793424751052,"version":"4.5.0"},"reference-count":29,"publisher":"Radiation Research Society","issue":"1","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Radiation Research"],"published-print":{"date-parts":[[2023,11,28]]},"abstract":"<jats:p>Ionizing radiation is one of the known risk factors for cataract development, however, there is still debate regarding the level of risk after low dose exposures. One of the largest sources of radiation exposure to the lens of the eye is diagnostic CT scans. The aim of this study was to examine whether ionizing radiation associated with head CT scans increases cataract risk in residents of Ontario, Canada. Data were collected from January 1, 1994 to December 31, 2015 (22 years) from anonymized Ontario Health Insurance Plan (OHIP) medical records for over 16 million subjects. A lens dose was estimated for each CT scan using the National Cancer Institute dosimetry system for CT (NCICT) program combined with Canada-specific CTDIvol data. Multivariate Cox proportional hazards analysis was performed with cataract extraction surgery as the primary outcome and lens dose as the main variable of interest, with inclusion of various medical and demographic covariates. Lag periods of 3, 5 and 7 years were incorporated. When lens dose was treated as a continuous variable, hazard ratios (per 100 mGy) ranged from 0.82 (0.80\u20130.84) to 1.10 (1.09\u20131.11) depending on the lag period. As a secondary analysis, when individuals were binned based on their total cumulative dose, no significant dose response pattern was observed in the low dose region. Overall, within the bounds of this study, the data do not support an increased risk of vision impairing cataracts after diagnostic head CT scan radiation exposure.<\/jats:p>","DOI":"10.1667\/rade-23-00179.1","type":"journal-article","created":{"date-parts":[[2023,11,28]],"date-time":"2023-11-28T04:58:50Z","timestamp":1701147530000},"page":"1-6","source":"Crossref","is-referenced-by-count":1,"title":["Assessment of Cataract Risk after Diagnostic Head CT Scan Radiation Exposure in Ontario, Canada"],"prefix":"10.1667","volume":"201","author":[{"given":"Pirouz","family":"Emami","sequence":"first","affiliation":[{"name":"Department of Physics & Astronomy, McMaster University, Hamilton, ON, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katherine","family":"Gaudreau","sequence":"additional","affiliation":[{"name":"Department of Physics & Astronomy, McMaster University, Hamilton, ON, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mark P.","family":"Little","sequence":"additional","affiliation":[{"name":"Department of Physics & Astronomy, McMaster University, Hamilton, ON, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Choonsik","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Physics & Astronomy, McMaster University, Hamilton, ON, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Brian","family":"Moroz","sequence":"additional","affiliation":[{"name":"Department of Physics & Astronomy, McMaster University, Hamilton, ON, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Douglas R.","family":"Boreham","sequence":"additional","affiliation":[{"name":"Department of Physics & Astronomy, McMaster University, Hamilton, ON, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christopher","family":"Thome","sequence":"additional","affiliation":[{"name":"Department of Physics & Astronomy, McMaster University, Hamilton, ON, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1243","reference":[{"key":"20","doi-asserted-by":"crossref","unstructured":"D. Schoenfeld,  \"Biometrika.\"  69, \"Partial residuals for the proportional hazards regression model.\" 239 (1982)","DOI":"10.1093\/biomet\/69.1.239"},{"key":"28","doi-asserted-by":"crossref","unstructured":"MS Pearce, JA Salotti, MP Little, et al.  \"Lancet.\"  380, \"Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study.\" 499 (2012)","DOI":"10.1016\/S0140-6736(12)60815-0"},{"key":"1","doi-asserted-by":"crossref","unstructured":"C Thome, DB Chambers, AM Hooker, et al.  \"Health Phys.\"  114, \"Deterministic effects to the lens of the eye following ionizing radiation exposure: Is there evidence to support a reduction in threshold dose?\" 328 (2018)","DOI":"10.1097\/HP.0000000000000810"},{"key":"3","doi-asserted-by":"crossref","unstructured":"K Neriishi, E Nakashima, M Akahoshi, et al.  \"Radiology.\"  265, \"Radiation dose and cataract surgery incidence in atomic bomb survivors, 1986\u20132005.\" 167 (2012)","DOI":"10.1148\/radiol.12111947"},{"key":"29","doi-asserted-by":"crossref","unstructured":"K Neriishi, E Nakashima, A Minamoto, et al.  \"Radiat Res.\"  168, \"Postoperative cataract cases among atomic bomb survivors: radiation dose response and threshold.\" 404 (2007)","DOI":"10.1667\/RR0928.1"},{"key":"8","doi-asserted-by":"crossref","unstructured":"F Hourihan, P Mitchell, RG Cumming,  \"Am J Public Health.\"  89, \"Possible associations between computed tomography scan and cataract: the Blue Mountains Eye Study.\" 1864 (1999)","DOI":"10.2105\/AJPH.89.12.1864"},{"key":"16","doi-asserted-by":"crossref","unstructured":"X Yu, D Lyu, X Dong, et al.  \"PLoS One.\"  9, \"Hypertension and risk of cataract: a meta-analysis.\" e114012 (2014)","DOI":"10.1371\/journal.pone.0114012"},{"key":"15","doi-asserted-by":"crossref","unstructured":"L Li, XH Wan, GH Zhao,  \"BMC Ophthalmol.\"  14, \"Meta-analysis of the risk of cataract in type 2 diabetes.\" 94 (2014)","DOI":"10.1186\/1471-2415-14-94"},{"key":"19","doi-asserted-by":"crossref","unstructured":"J Cologne, WL Hsu, RD Abbott, et al.  \"Epidemiology.\"  23, \"Proportional hazards regression in epidemiologic follow-up studies: an intuitive consideration of primary time scale.\" 565 (2012)","DOI":"10.1097\/EDE.0b013e318253e418"},{"key":"24","doi-asserted-by":"crossref","unstructured":"A Minamoto, H Taniguchi, N Yoshitani, et al.  \"Int J Radiat Biol.\"  80, \"Cataract in atomic bomb survivors.\" 339 (2004)","DOI":"10.1080\/09553000410001680332"},{"key":"26","doi-asserted-by":"crossref","unstructured":"TV Azizova, N Hamada, ES Grigoryeva, et al.  \"Eur J Epidemiol.\"  33, \"Risk of various types of cataracts in a cohort of Mayak workers following chronic occupational exposure to ionizing radiation.\" 1193 (2018)","DOI":"10.1007\/s10654-018-0450-4"},{"key":"25","doi-asserted-by":"crossref","unstructured":"MP Little, CM Kitahara, EK Cahoon, et al.  \"Eur J Epidemiol.\"  33, \"Occupational radiation exposure and risk of cataract incidence in a cohort of US radiologic technologists.\" 1179 (2018)","DOI":"10.1007\/s10654-018-0435-3"},{"key":"2","unstructured":"\"ICRP Publication 103. Ann ICRP.\"  37, \"The 2007 Recommendations of the International Commission on Radiological Protection.\" (2007)"},{"key":"4","doi-asserted-by":"crossref","unstructured":"\"Ann ICRP.\"  41, \"ICRP Statement on Tissue Reactions\/Early and Late Effects of Radiation in Normal Tissues and Organs\u2013Threshold Doses for Tissue Reactions in a Radiation Protection Context. ICRP Publication 118.\" (2012)","DOI":"10.1016\/j.icrp.2012.02.001"},{"key":"5","unstructured":"\"Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards.\"  (2014)"},{"key":"6","doi-asserted-by":"crossref","unstructured":"BE Klein, R Klein, K Linton, et al.  \"Am J Public Health.\"  83, \"Diagnostic x-ray exposure and lens opacities: the Beaver Dam Eye Study.\" 588 (1993)","DOI":"10.2105\/AJPH.83.4.588"},{"key":"7","doi-asserted-by":"crossref","unstructured":"BE Klein, R Klein, SE Moss,  \"Ophthalmic Epidemiol.\"  7, \"Exposure to diagnostic x-rays and incident age-related eye disease.\" 61 (2000)","DOI":"10.1076\/0928-6586(200003)711-2FT061"},{"key":"9","doi-asserted-by":"crossref","unstructured":"M-K Yuan, D-C Tsai, S-C Chang, et al.  \"Am J Roentgenol.\"  201, \"The risk of cataract associated with repeated head and neck CT studies: a nationwide population-based study.\" 626 (2013)","DOI":"10.2214\/AJR.12.9652"},{"key":"10","doi-asserted-by":"crossref","unstructured":"K Gaudreau, C Thome, B Weaver, et al.  \"Radiat Res.\"  193, \"Cataract formation and low-dose radiation exposure from head computed tomography (CT) scans in Ontario, Canada, 1994\u20132015.\" 322 (2020)","DOI":"10.1667\/RR15504.1"},{"key":"11","doi-asserted-by":"crossref","unstructured":"R Poon  and MK Badawy  \"J Med Imaging Radiat Oncol.\"  63, \"Radiation dose and risk to the lens of the eye during CT examinations of the brain.\" 786 (2019)","DOI":"10.1111\/1754-9485.12950"},{"key":"12","unstructured":"B. Kralj,  \"Measuring rurality - RIO 2008_BASIC: methodology and results.\"  (2013)"},{"key":"13","doi-asserted-by":"crossref","unstructured":"SS Jick, C Vasilakis-Scaramozza, WC Maier,  \"Epidemiology.\"  12, \"The risk of cataract among users of inhaled steroids.\" 229 (2001)","DOI":"10.1097\/00001648-200103000-00016"},{"key":"14","doi-asserted-by":"crossref","unstructured":"A Nemet, S Vinker, S Levartovsky, et al.  \"Eye.\"  24, \"Is cataract associated with cardiovascular morbidity?\" 1352 (2010)","DOI":"10.1038\/eye.2010.34"},{"key":"17","doi-asserted-by":"crossref","unstructured":"SC Fang, CY Huang, DL Liao, et al.  \"Schizophr Res.\"  212, \"Associations among antipsychotics, metabolism-related diseases, and cataracts in patients with schizophrenia: A retrospective cohort study.\" 150 (2019)","DOI":"10.1016\/j.schres.2019.07.049"},{"key":"18","doi-asserted-by":"crossref","unstructured":"C Lee, B Moroz, C Thome, et al.  \"Rad Prot Dosim.\"  \"Reconstruction of organ doses for patients undergoing computed tomography examinations in Canada 1992 - 2019.\" (2023)","DOI":"10.1093\/rpd\/ncad315"},{"key":"21","doi-asserted-by":"crossref","unstructured":"E Chan, OAR Mahroo, DJ Spalton,  \"Clin Exp Optom.\"  93, \"Complications of cataract surgery.\" 379 (2010)","DOI":"10.1111\/j.1444-0938.2010.00516.x"},{"key":"22","doi-asserted-by":"crossref","unstructured":"N Abdeen, S Chakraborty, T Nguyen, et al.  \"Clin Radiol.\"  65, \"Comparison of image quality and lens dose in helical and sequentially acquired head CT.\" 868 (2010)","DOI":"10.1016\/j.crad.2010.02.016"},{"key":"23","doi-asserted-by":"crossref","unstructured":"A Ploussi, I Stathopoulos, V Syrgiamiotis, et al.  \"Radiat Prot Dosim.\"  179, \"Direct measurements of skin, eye lens and thyroid dose during pediatric brain CT examinations.\" 199 (2018)","DOI":"10.1093\/rpd\/ncx251"},{"key":"27","doi-asserted-by":"crossref","unstructured":"A Berrington de Gonzalez, M Mahesh, KP Kim, et al.  \"Arch Intern Med.\"  169, \"Projected cancer risks from computed tomographic scans performed in the United States in 2007.\" 2071 (2009)","DOI":"10.1001\/archinternmed.2009.440"}],"container-title":["Radiation Research"],"original-title":[],"link":[{"URL":"https:\/\/meridian.allenpress.com\/radiation-research\/article-pdf\/doi\/10.1667\/RADE-23-00179.1\/3294650\/10.1667_rade-23-00179.1.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/meridian.allenpress.com\/radiation-research\/article-pdf\/doi\/10.1667\/RADE-23-00179.1\/3294650\/10.1667_rade-23-00179.1.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,31]],"date-time":"2026-10-31T05:04:26Z","timestamp":1793423066000},"score":1,"resource":{"primary":{"URL":"https:\/\/bioone.org\/journals\/radiation-research\/volume-201\/issue-1\/RADE-23-00179.1\/Assessment-of-Cataract-Risk-after-Diagnostic-Head-CT-Scan-Radiation\/10.1667\/RADE-23-00179.1.full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,11,28]]},"references-count":29,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2024,1,1]]}},"URL":"https:\/\/doi.org\/10.1667\/rade-23-00179.1","relation":{},"ISSN":["0033-7587","1938-5404"],"issn-type":[{"value":"0033-7587","type":"print"},{"value":"1938-5404","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,11,28]]}}}