Variation DM optic nerve head topography in patients with untreated idiopathicintracranial hypertension

Purpose. To determine the variation in the appearance of the optic nerve head in patients with papilloedema with suspected idiopathic intracranial hypertension (IIH) before treatment was initiated. Methods, We have tested four patients so far referred to our neuro-ophthalmology service with papilloedema and suspected UK. Each patient was imaged over at least three sessions (separated by 2-7 days) before a diagnosis of IIH was confirmed with a lumbar puncture (cerebrospinal fluid pressure, CSFP > 220 mm HO). In each session we obtained six high-quality images of the optic nerve head and peripapillary retina using the Heidelberg Retina Tomograph (HRT). In one patient we obtained six sets of images over a period of one day (from 7 am to 10pm). We compared the first set of images to subsequent ones using a recently developed method for detecting changes based on probability maps (ARVO, 1994, 1996). K&UJ& In all patients we noticed significant changes in the optic nerve head and peripapillary retina (up to 120 u,m) from one session to another. Typically the direction of the change (either elevation or depression) reversed at subsequent sessions. These changes were larger and more significant than random change or "noise" that occurred between images over one session. Conclusion Previous studies using CSFP monitors have shown large swings in CSFP in IIH patients. This study in addition to our previous work on experimental modulation of CSFP in animals confirms that changes in CSFP have profound effects on optic nerve head topography.