Patients with idiopathic intracranial hypertension (IIH) often present papilledema at the optic nerve head (ONH), associated with visual field losses. In order to quantify the edema, the computation of its volume is needed. Optical coherence tomography (OCT) is a noninvasive method for spatial imaging of retinal layer composition. However, current algorithms fail to segment the ONH in IIH patients satisfactorily. We developed an automatic method for segmenting the retinal pigment epithelium layer (RPE) from spatial high-resolution OCT ONH scans with robust performance in IIH patients. Using a hypothetical extension of the RPE through the ONH we were able to compute ONH height and volume. Using this algorithm we could automatically detect differences in ONH volume and height between healthy controls and IIH patients.Quantifying ONH edema in IIH is potentially important for diagnosis and especially for monitoring progression and treatment effectiveness.