title: Neuroretinal rim area and ocular haemodynamic parameters in patients with normal-tension glaucoma with differing intracranial pressures.
abstract: To assess the differences in the neuroretinal rim area (NRA) and ocular haemodynamic parameters in patients with normal-tension glaucoma (NTG) with differing intracranial pressure (ICP) values.
  
  
  
  40 patients (11 males) with NTG (age 61.1 (11.5)) were included in the prospective study. Intraocular pressure (IOP), non-invasive ICP, retrobulbar blood flow (RBF) and confocal laser scanning tomography for optic nerve disc (OND) structural parameters were assessed. Non-invasive ICP was measured using a novel two-depth Transcranial Doppler device. RBF was measured using colour Doppler imaging in the ophthalmic artery (OA). The patients were divided into two groups, ICP ≥ and <8.3 mm Hg, based on the statistical median of ICP. p Values <0.05 were considered statistically significant.
  
  
  
  Patients with NTG had mean ICP 8.8 (2.5) mm Hg, IOP 13.6 (2.1) mm Hg, OND size 2.3 (0.6) mm(2), NRA 1.2 (0.4) mm(2). Lower ICP was correlated with decreased NRA (r=0.51, p=0.001). Patients with NTG having lower ICP (N=20) had significantly lower NRA 1.0 (0.3) mm(2), than patients with NTG having higher ICP (N=20) 1.3 (0.3) mm(2), p=0.002, although there were no significant differences in OND size (accordingly, 2.2 (0.5) and 2.3 (0.6) mm(2), p=0.55) and IOP (accordingly, 13.5 (2.4) and 13.7 (1.8) mm Hg, p=0.58). Patients with NTG having lower ICP had significantly lower OA blood flow velocities (peak systolic volume (PSV) 28.7 (8.0), end-diastolic volume (EDV) 6.9 (3.0) cm/s), compared with patients with NTG having higher ICP (PSV 35.5 (10.2), EDV 9.4 (4.1) cm/s), p<0.04.
  
  
  
  Patients with NTG having lower ICP have decreased neuroretinal rim area and OA blood flow parameters compared with patients having higher ICP. Further longitudinal studies are needed to analyse the involvement of ICP in NTG management.
authors.affiliation: Eye Clinic, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Lina
authors.initials: L
authors.lastname: Siaudvytyte
authors.affiliation: Eye Clinic, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Ingrida
authors.initials: I
authors.lastname: Januleviciene
authors.affiliation: Eye Clinic, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Akvile
authors.initials: A
authors.lastname: Daveckaite
authors.affiliation: Health Telematics Science Centre of Kaunas, University of Technology, Kaunas, Lithuania.
authors.forename: Arminas
authors.initials: A
authors.lastname: Ragauskas
authors.affiliation: Glaucoma Research and Diagnostic Center, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: Brent
authors.initials: B
authors.lastname: Siesky
authors.affiliation: Glaucoma Research and Diagnostic Center, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: Alon
authors.initials: A
authors.lastname: Harris
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007427:Intracranial Pressure; D007429:Intraocular Pressure / Q000502:physiology*; D057066:Low Tension Glaucoma / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009880:Ophthalmic Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D009898:Optic Disk / Q000098:blood supply*; D011446:Prospective Studies; D012039:Regional Blood Flow / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000473:pathology; D017585:Ultrasonography, Doppler, Transcranial
keywords: Glaucoma