Relationship between Intracranial Pressure and Intraocular Pressure in the Setting of Traumatic Brain Injury

Can Intraocular Pressure Measurements be Used to Screen for Elevated Intracranial Pressure in Emergency Department Patients?

“…A similar study, also conducted by Lashutka et al, at a community Level II trauma center among traumaticbrain-injured patients with intracranial monitors, demonstrated a positive correlation (3). IOP was measured with the Tono-Pen XL in this study as well.…”

“…Such patients tend to be much more symptomatic, and are most likely undergoing diagnostic tests such as lumbar puncture or a radiographic study. In a previous study, elevated IOP was highly predictive of increased ICP (1,3). The patients evaluated in the present study were neuro-trauma intensive care unit patients and all had ventriculostomies.…”

“…A non-invasive screening tool also could help to identify patients who have subtle RECEIVED: 17 September 2009; FINAL SUBMISSION RECEIVED: 6 January 2010; ACCEPTED: 7 April 2010 symptoms yet have a life-threatening condition. Several authors suggest that intraocular pressure (IOP) directly reflects ICP and that IOP measurement may be used as a surrogate for ICP (1)(2)(3). There have been some studies suggesting that non-invasive measurement of IOP is highly sensitive, however, these studies were conducted in patients in neurosurgical or trauma intensive care units and the patients all had invasive intracranial monitoring devices.…”

Accuracy of Noninvasive Intraocular Pressure or Optic Nerve Sheath Diameter Measurements for Predicting Elevated Intracranial Pressure in Cryptococcal Meningitis

“…The IOP was then measured again in both eyes at the conclusion of the LP. Normal IOP is <18 mm Hg, and normal ICP is <200 mm H 2 O [ 16 , 20 , 26 ] (pressure conversion: 1 mm Hg = 13.6 mm H 2 O).…”

“…Tonometers are easy to use, have excellent interoperator reproducibility within ±2.5 mm Hg, and are not dependent on patient position [ 14 , 15 ]. Yet, prior attempts to correlate IOP with ICP have mixed results among studies of traumatic brain injury, idiopathic intracranial hypertension, and subarachnoid or intracranial hemorrhage; overall, the current evidence does not support IOP measurement as a predictor of ICP in these conditions [ 16 – 20 ]. A 2004 study demonstrated that among traumatic brain injury patients sedated in an intensive care unit, IOPs >20 mm Hg correlated well with increased ICPs >200 mm H 2 O [ 16 ], although this study was not blinded.…”