A novel biomarker for increased intracranial pressure in idiopathic intracranial hypertension.

PURPOSE Changes in optic disc and peripapillary structures associated with optic nerve edema in idiopathic intracranial hypertension (IIH), can be evaluated with spectral domain optical coherence tomography (SD-OCT). We aimed to evaluate the association between increased cerebrospinal fluid (CSF) opening pressure and changes in peripapillary structures detected by SD-OCT and to determine whether these changes can be used to assess the changes in CSF pressure without performing lumbar puncture (LP). STUDY DESIGN Retrospective study METHODS: We included 54 eyes of 28 patients with bilateral papilledema who had peripapillary SD-OCT imaging within 24 h before the LP. Correlation between CSF pressure and peripapillary OCT parameters including maximal retinal thickness, maximal anterior retinal projection, maximal retinal nerve fiber layer (RNFL) thickness and Bruch membrane opening (BMO) was evaluated. RESULTS Bruch Membrane opening and maximal RNFL thickness were significantly higher in patients with increased CSF pressure. There exist correlations between CSF pressure and BMO, maximal RNFL thickness and maximal retinal thickness. (Spearman's Rho: 0.791, 0.482 and 0.297, p < 0.001, < 0.001 and 0.029, respectively) The cut off value of BMO for the prediction of increased CSF pressure was 1785 µm, with a sensitivity of 78.8% and a specificity of 81%. The cut off value for maximal RNFL thickness was 174 µm, with a sensitivity of 75.8% and a specificity of 61.9%. CONCLUSION Bruch membrane opening and maximal RNFL thickness can give an idea about increased CSF pressure values in IIH patients. Thus SD-OCT can be used to detect CSF pressure changes in these patients.