title: Poor correlation between intracranial pressure and intraocular pressure by hand-held tonometry.
abstract: OBJECTIVE
  The aim of this study is to provide data on the controversial issue of whether handheld measurements of intraocular pressure (IOP) are capable of accurately predicting elevated intracranial pressure (ICP) in patients undergoing lumbar puncture (LP).
  
  
  METHODS
  All patients over the age of 18 years who underwent an LP in the emergency or neurological departments at the Tel Aviv Medical Center for any reason between October 2007 and July 2010 were eligible to participate in this prospective observational pilot study. IOP was measured with the Tono-Pen XL while patients were in the supine position before undergoing LP. ICP was measured in the lateral recumbent position. ICP and bilateral IOP were measured, and the mean and maximum values of IOP were calculated. The association between ICP and each one of the four IOP measures was evaluated by the Pearson correlation coefficient.
  
  
  RESULTS
  Twenty-four patients (mean age 37.8 ± 15.8 years, ten males and 14 females) were enrolled. The reasons for their requiring an LP were headache (19/24 patients), evaluation for hemiparesis (2/24), cognitive deterioration (1/24), and seizures (2/24). Nine had elevated mean opening pressure (>20 cm H2O), six had an elevated mean IOP (>20 mmHg), and four of these six also had an elevated opening pressure. There was no significant correlation between the ICP measurements and any of the IOP measurements.
  
  
  CONCLUSIONS
  Handheld ocular tonometry has poor sensitivity and specificity for the prediction of increased ICP and is not an effective tool for screening for ICP in the ED or in the neurology department.
authors.affiliation: Department of Ophthalmology, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Shani
authors.initials: S
authors.lastname: Golan
authors.forename: Shimon
authors.initials: S
authors.lastname: Kurtz
authors.forename: Daphna
authors.initials: D
authors.lastname: Mezad-Koursh
authors.forename: Michael
authors.initials: M
authors.lastname: Waisbourd
authors.forename: Anat
authors.initials: A
authors.lastname: Kesler
authors.forename: Pinchas
authors.initials: P
authors.lastname: Halpern
keywords: ICP; IOP; Tono-Pen; intracranial pressure; intraocular pressure; ocular tonometry