Measurement of intraocular and intracranial pressure: is there a relationship?

OBJECTIVE: To study whether noninvasive, intraocular pressure (IOP) measurements significantly correlate with standard intracranial pressure (ICP) measurements. METHODS: This prospective, blinded study enrolled 46 patients who were undergoing medically indicated lumbar puncture (LP). IOP was measured by applanation tonometry immediately prior to measuring LP opening pressure. One patient was excluded due to unsuccessful ICP measurement. RESULTS: In the 45 patients to successfully undergo IOP and ICP measurement, there was no significant relationship between ICP and average IOP for both eyes (r = -0.005). There was no significant relationship between ICP and IOP in either eye, when studied individually(r = 0.03 ocular dexter [OD], r = -0.05 ocular sinister [OS]). There was no significant relationship between ICP and IOP when the eye best correlated to the patient's ICP was chosen (r = -0.01). INTERPRETATION: No significant relationship between ICP and IOP was observed. Noninvasive IOP measurements do not predict ICP.