title: The risk of cataractogenesis after gamma knife radiosurgery: a nationwide population based case-control study.
abstract: BACKGROUND
  Medical radiation is considered a factor responsible for cataractogenesis. However, the incidence of this ophthalmologic complication resulting from gamma knife radiosurgery (GKRS) has not yet been reported. The present study aimed to determine the risk of cataractogenesis associated with radiation exposure from GKRS.
  
  
  METHODS
  This study used information from a random sample of one million persons enrolled in the nationally representative Taiwan National Health Insurance Research Database. The GK group consisted of patients who underwent GKRS between 2000 and 2009. The non-GK group was composed of subjects who had never undergone GKRS, but who were matched with the case group for time of enrollment, age, sex, history of coronary artery disease, hypertension, and diabetes.
  
  
  RESULTS
  There were 277 patients in the GK group and 2770 matched subjects in the non-GK group. The GK group had a higher overall incidence of cataracts (10.11% vs. 7.26%; crude hazard ratio [cHR], 1.59; 95% CI, 1.07-2.36; adjusted hazard ratio [aHR], 1.25; 95% CI, 0.82-1.90) than the non-GK group. Patients who had undergone computed tomography and/or cerebral angiography (CT/angio) studies had a higher risk of developing cataracts than those who did not (10.82% vs. 6.64%; cHR, 1.74; 95% CI, 1.31-2.30; aHR, 1.65; 95% CI, 1.22-2.23). The age group between 30 and 50 years had the highest risk of cataractogenesis in both the GK and CT/angio groups (cHR, 3.50; 95% CI, 1.58-7.72; aHR, 2.43; 95% CI, 1.02-5.81; cHR, 2.96; 95% CI, 1.47-5.99; aHR, 2.27; 95% CI, 1.05-4.93, respectively).
  
  
  CONCLUSIONS
  Radiation exposure due to GKRS and CT/angio study may be independently associated with increased risk of cataractogenesis. We suggest routine dosimetry measurement of eye lens and proper protection for patients with benign lesions during GKRS. Regular follow-up imaging studies should avoid the use of CT/angio, and particular care should be taken in the 30-50-year-old age group, due to their significantly increased risk of cataract formation.
authors.affiliation: Department of Neurosurgery, E-Da Hospital, I-Shou University School of Medicine, 1, E-Da Road, Yan-Chou District, Kaohsiung, 824, Taiwan. ed100183@edah.org.tw.
authors.forename: Cheng-Loong
authors.initials: CL
authors.lastname: Liang
authors.affiliation: Department of Neurosurgery, E-Da Hospital, I-Shou University School of Medicine, 1, E-Da Road, Yan-Chou District, Kaohsiung, 824, Taiwan.
authors.forename: Po-Chou
authors.initials: PC
authors.lastname: Liliang
authors.affiliation: Department of Medical Imaging and Radiological Sciences, I-Shou University, Kaohsiung, Taiwan.
authors.forename: Tai-Been
authors.initials: TB
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, E-Da Hospital, Kaohsiung, Taiwan.
authors.forename: Huan-Chen
authors.initials: HC
authors.lastname: Hsu
authors.affiliation: Department of Radiation Oncology, E-Da Hospital, Kaohsiung, Taiwan.
authors.forename: Fu-Cheng
authors.initials: FC
authors.lastname: Chuang
authors.affiliation: Department of Neurosurgery, E-Da Hospital, I-Shou University School of Medicine, 1, E-Da Road, Yan-Chou District, Kaohsiung, 824, Taiwan.
authors.forename: Kuo-Wei
authors.initials: KW
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, E-Da Hospital, I-Shou University School of Medicine, 1, E-Da Road, Yan-Chou District, Kaohsiung, 824, Taiwan.
authors.forename: Hao-Kuang
authors.initials: HK
authors.lastname: Wang
authors.affiliation: Department of Pediatrics, E-Da Hospital, I-Shou University School of Medicine, Kaohsiung, Taiwan.
authors.forename: San-Nan
authors.initials: SN
authors.lastname: Yang
authors.affiliation: Department of Neurosurgery, E-Da Hospital, I-Shou University School of Medicine, 1, E-Da Road, Yan-Chou District, Kaohsiung, 824, Taiwan.
authors.forename: Han-Jung
authors.initials: HJ
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D002386:Cataract / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D015994:Incidence; D007908:Lens, Crystalline / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods*; D011832:Radiation Injuries / Q000150:complications* / Q000453:epidemiology; D016634:Radiosurgery / Q000009:adverse effects*; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D013624:Taiwan / Q000453:epidemiology
keywords: Cataractogenesis; Cerebral angiography; Computed tomography; Gamma knife radiosurgery; Lens