title: Diagnostic accuracy of intraocular pressure measurement for the detection of raised intracranial pressure: meta-analysis: a systematic review.
abstract: OBJECTIVE
  Because clinical examination and imaging may be unreliable indicators of intracranial hypertension, intraocular pressure (IOP) measurement has been proposed as a noninvasive method of diagnosis. The authors conducted a systematic review and meta-analysis to determine the correlation between IOP and intracranial pressure (ICP) and the diagnostic accuracy of IOP measurement for detection of intracranial hypertension.
  
  
  METHODS
  The authors searched bibliographic databases (Ovid MEDLINE, Ovid EMBASE, and the Cochrane Central Register of Controlled Trials) from 1950 to March 2013, references of included studies, and conference abstracts for studies comparing IOP and invasive ICP measurement. Two independent reviewers screened abstracts, reviewed full-text articles, and extracted data. Correlation coefficients, sensitivity, specificity, and positive and negative likelihood ratios were calculated using DerSimonian and Laird methods and bivariate random effects models. The I(2) statistic was used as a measure of heterogeneity.
  
  
  RESULTS
  Among 355 identified citations, 12 studies that enrolled 546 patients were included in the meta-analysis. The pooled correlation coefficient between IOP and ICP was 0.44 (95% CI 0.26-0.63, I(2) = 97.7%, p < 0.001). The summary sensitivity and specificity for IOP for diagnosing intracranial hypertension were 81% (95% CI 26%-98%, I(2) = 95.2%, p < 0.01) and 95% (95% CI 43%-100%, I(2) = 97.7%, p < 0.01), respectively. The summary positive and negative likelihood ratios were 14.8 (95% CI 0.5-417.7) and 0.2 (95% CI 0.02-1.7), respectively. When ICP and IOP measurements were taken within 1 hour of another, correlation between the measures improved.
  
  
  CONCLUSIONS
  Although a modest aggregate correlation was found between IOP and ICP, the pooled diagnostic accuracy suggests that IOP measurement may be of clinical utility in the detection of intracranial hypertension. Given the significant heterogeneity between included studies, further investigation is required prior to the adoption of IOP in the evaluation of intracranial hypertension into routine practice.
authors.affiliation: Departments of Clinical Neurosciences.
authors.forename: Daniel
authors.initials: D
authors.lastname: Yavin
authors.forename: Judy
authors.initials: J
authors.lastname: Luu
authors.forename: Matthew T
authors.initials: MT
authors.lastname: James
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Roberts
authors.forename: Garnette R
authors.initials: GR
authors.lastname: Sutherland
authors.forename: Nathalie
authors.initials: N
authors.lastname: Jette
authors.forename: Samuel
authors.initials: S
authors.lastname: Wiebe
mesh_terms: D000328:Adult; D000368:Aged; D002675:Child, Preschool; D006801:Humans; D019586:Intracranial Hypertension / Q000175:diagnosis* / Q000503:physiopathology; D007429:Intraocular Pressure / Q000502:physiology*; D008875:Middle Aged; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014065:Tonometry, Ocular / Q000379:methods*
keywords: ED = emergency department; ICP = intracranial pressure; ICU = intensive care unit; IOP = intraocular pressure; LP = lumbar puncture; QUADAS = Quality Assessment of Diagnostic Accuracy Studies; diagnostic accuracy; intracranial hypertension; intracranial pressure; intraocular pressure; meta-analysis; systematic review