title: Diabetes, fasting glucose, and the risk of glaucoma: a meta-analysis.
abstract: OBJECTIVE
  We performed a systematic review to summarize the association of diabetes and blood glucose levels with glaucoma, intraocular pressure (IOP), and ocular hypertension in the general population.
  
  
  CONCLUSIONS
  Diabetes has been proposed as a risk factor for glaucoma, but epidemiologic studies have been inconsistent, and the association is still controversial. Furthermore, no systematic reviews evaluated other metabolic abnormalities, such as the metabolic syndrome, with the risk of glaucoma.
  
  
  METHODS
  We identified the studies by searching the PubMed and EMBASE databases. We used inverse-variance weighted random-effects models to summarize relative risks across studies.
  
  
  RESULTS
  We identified 47 studies including 2 981 342 individuals from 16 countries. The quality of evidence generally was higher in the cohort compared with case-control or cross-sectional studies. The pooled relative risk for glaucoma comparing patients with diabetes with those without diabetes was 1.48 (95% confidence interval [CI], 1.29-1.71), with significant heterogeneity across studies (I(2) = 82.3%; P < 0.001). The risk of glaucoma increased by 5% (95% CI, 1%-9%) for each year since diabetes diagnosis. The pooled average difference in IOP comparing patients with diabetes with those without diabetes was 0.18 mmHg (95% CI, 0.09-0.27; I(2) = 73.2%), whereas the pooled average increase in IOP associated with an increase in 10 mg/dl in fasting glucose was 0.09 mmHg (95% CI, 0.05-0.12; I(2) = 34.8%).
  
  
  CONCLUSIONS
  Diabetes, diabetes duration, and fasting glucose levels were associated with a significantly increased risk of glaucoma, and diabetes and fasting glucose levels were associated with slightly higher IOP.
authors.affiliation: Department of Epidemiology and Welch Center for Prevention, Epidemiology, and Clinical Research, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland.
authors.forename: Di
authors.initials: D
authors.lastname: Zhao
authors.affiliation: Department of Epidemiology and Welch Center for Prevention, Epidemiology, and Clinical Research, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland; Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, Korea; Biostatistics and Clinical Epidemiology Center, Research Institute for Future Medicine, School of Medicine, Samsung Medical Center, Sungkyunkwan University, Seoul, Korea.
authors.forename: Juhee
authors.initials: J
authors.lastname: Cho
authors.affiliation: Saevit Eye Hospital, Goyang, Gyeonggi-do, Korea; Department of Epidemiology, Graduate School of Public Health, Seoul National University, Seoul, Korea. Electronic address: philip.mhkim@gmail.com.
authors.forename: Myung Hun
authors.initials: MH
authors.lastname: Kim
authors.affiliation: Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland.
authors.forename: David S
authors.initials: DS
authors.lastname: Friedman
authors.affiliation: Department of Epidemiology and Welch Center for Prevention, Epidemiology, and Clinical Research, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland.
authors.forename: Eliseo
authors.initials: E
authors.lastname: Guallar
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D048909:Diabetes Complications; D005902:Glaucoma, Open-Angle / Q000209:etiology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D024821:Metabolic Syndrome / Q000150:complications*; D009798:Ocular Hypertension / Q000209:etiology; D012307:Risk Factors
chemical_list: D001786:Blood Glucose