title: Hypertension and risk of cataract: a meta-analysis.
abstract: BACKGROUND
  Cataract is the major cause of blindness across the world. Many epidemiologic studies indicated that hypertension might play an important role in the development of cataract, while others not. We therefore conducted this meta-analysis to determine the relationship between risk of cataract and hypertension.
  
  
  METHODS
  Retrieved studies on the association of hypertension with cataract risk were collected from PubMed, Web of Science and the Cochrane Library during June 2014 and were included into the final analysis according to the definite inclusion criteria. Odds ratio (OR) or risk ratio (RR) were pooled with 95% confidence interval (CI) to evaluate the relationship between hypertension and cataract risk. Subgroup analyses were carried out on the basis of cataract type, race and whether studies were adjusted for main components of metabolic syndrome (MS).
  
  
  RESULTS
  The final meta-analysis included 25 studies (9 cohort, 5 case-control and 11 cross-sectional) from 23 articles. The pooled results showed that cataract risk in populations with hypertension significantly increased among cohort studies (RR 1.08; 95% CI: 1.05-1.12) and case-control or cross-sectional studies (OR 1.28; 95% CI: 1.12-1.45). This association was proved to be true among both Mongolians and Caucasians, and the significance was not altered by the adjustment of main components of MS. Subgroup analysis on cataract types indicated that an increased incidence of posterior subcapsular cataract (PSC) resulted among cohort studies (RR 1.22; 95% CI: 1.03-1.46) and cross-sectional/case-control studies (OR 1.23; 95% CI: 1.09-1.39). No association of hypertension with risk of nuclear cataract was found.
  
  
  CONCLUSIONS
  The present meta-analysis suggests that hypertension increases the risk of cataract, especially PSC. Further efforts should be made to explore the potential biological mechanisms.
authors.affiliation: Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Yu
authors.affiliation: Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Danni
authors.initials: D
authors.lastname: Lyu
authors.affiliation: Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Xinran
authors.initials: X
authors.lastname: Dong
authors.affiliation: Institutes of Environmental Medicine, School of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Jiliang
authors.initials: J
authors.lastname: He
authors.affiliation: Eye Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Yao
mesh_terms: D002386:Cataract / Q000150:complications*; D015331:Cohort Studies; D006801:Humans; D006973:Hypertension / Q000150:complications*; D012306:Risk