title: Optical coherence tomography of the optic nerve head detects acute changes in intracranial pressure.
abstract: We aimed to determine if there are measurable objective changes in the optic nerve head (ONH) immediately after cerebrospinal fluid (CSF) drainage in a prospective case-series of five patients undergoing a clinically indicated lumbar puncture (LP) for diagnosis of idiopathic intracranial hypertension. A Cirrus high-definition optical coherence tomography machine (Carl Zeiss Meditec, Dublin, CA, USA) was used to acquire images in the lateral decubitus position. Optic disc cube and high-definition line raster scans centered on the ONH were obtained immediately before and after draining CSF, while the patient maintained the lateral decubitus position. Measured parameters included retinal nerve fiber layer (RNFL) thickness, peripapillary retinal pigment epithelium/Bruch's membrane (RPE/BM) angulation, transverse neural canal diameter (NCD) and the highest vertical point of the internal limiting membrane from the transverse diameter (papillary height). The mean (±standard deviation) opening and closing CSF pressures were 34.3±11.8 and 11.6±3.3cmH2O, respectively. Mean RNFL thickness (pre LP: 196±105μm; post LP: 164±77μm, p=0.1) and transverse NCD (pre LP: 1985±559μm; post LP: 1590±228μm, p=2.0) decreased in all subjects, but with non-significant trends. The RPE/BM angle (mean change: 5.8±2.0degrees, p=0.003) decreased in all subjects. A decrease in papillary height was seen in three of five subjects (mean: pre LP: 976±275μm; post LP: 938±300μm, p=0.9). Our results show a measurable, objective change in the ONH after acute lowering of the lumbar CSF pressure, suggesting a direct link between the lumbar subarachnoid space and ONH regions, and its potential as a non-invasive method for monitoring intracranial pressures.
authors.affiliation: Division of Vascular Neurology and Neurocritical Care, Baylor College of Medicine, Department of Neurology, Baylor St Luke's Medical Center, One Baylor Plaza, NB302, Houston, TX 77030, USA.
authors.forename: Aashish
authors.initials: A
authors.lastname: Anand
authors.affiliation: University of Houston, School of Optometry, Houston, TX, USA.
authors.forename: Anastas
authors.initials: A
authors.lastname: Pass
authors.affiliation: Division of Vascular Neurology and Neurocritical Care, Baylor College of Medicine, Department of Neurology, Baylor St Luke's Medical Center, One Baylor Plaza, NB302, Houston, TX 77030, USA.
authors.forename: Mian Z
authors.initials: MZ
authors.lastname: Urfy
authors.affiliation: University of Houston, School of Optometry, Houston, TX, USA.
authors.forename: Rosa
authors.initials: R
authors.lastname: Tang
authors.affiliation: University of Houston, School of Optometry, Houston, TX, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Cajavilca
authors.affiliation: Division of Vascular Neurology and Neurocritical Care, Baylor College of Medicine, Department of Neurology, Baylor St Luke's Medical Center, One Baylor Plaza, NB302, Houston, TX 77030, USA.
authors.forename: Eusebia
authors.initials: E
authors.lastname: Calvillo
authors.affiliation: Division of Vascular Neurology and Neurocritical Care, Baylor College of Medicine, Department of Neurology, Baylor St Luke's Medical Center, One Baylor Plaza, NB302, Houston, TX 77030, USA.
authors.forename: Jose I
authors.initials: JI
authors.lastname: Suarez
authors.affiliation: Division of Vascular Neurology and Neurocritical Care, Baylor College of Medicine, Department of Neurology, Baylor St Luke's Medical Center, One Baylor Plaza, NB302, Houston, TX 77030, USA.
authors.forename: Chethan P
authors.initials: CP
authors.lastname: Venkatasubba Rao
authors.affiliation: Division of Vascular Neurology and Neurocritical Care, Baylor College of Medicine, Department of Neurology, Baylor St Luke's Medical Center, One Baylor Plaza, NB302, Houston, TX 77030, USA. Electronic address: bershad@bcm.edu.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Bershad
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D009898:Optic Disk / Q000000981:diagnostic imaging*; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011446:Prospective Studies; D011559:Pseudotumor Cerebri / Q000000981:diagnostic imaging* / Q000601:surgery*; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: Idiopathic intracranial hypertension; Intracranial pressure; Optic nerve; Optical coherence tomography