Ocular Perfusion in Patients With Idiopathic Intracranial Hypertension

The proposed study aims to evaluate optic nerve head blood flow and microcirculation in patients with idiopathic intracranial hypertension. For this purpose, optic nerve head blood flow will be examined in patients with IIH before and after therapy and additionally compared with healthy age- and sex-matched control subjects. In addition, other parameters will be measured, in particular retinal blood flow, retinal oxygen saturation and retinal neurovascular coupling.

Study Overview

• Status: Recruiting
• Conditions: Idiopathic Intracranial Hypertension
• Intervention / Treatment: Other: Lumbar puncture and administration of medication

Detailed Description

Idiopathic intracranial hypertension (IIH) is a neuroophthalmological disease, characterized by an increased intracranial pressure (ICP) without an identifiable causative factor. If not properly treated and carefully monitored the disease can even lead to irreversible severe or complete loss of vision or severe irreversible visual field defects, respectively. Given this clinical urgency, precise diagnostic tools become essential for timely decision making.

Laser Speckle Flowgraphy (LSFG) is a non-invasive, in-vivo imaging method, which quantitatively estimates blood flow in the optic nerve head, the choroid, the retina and the iris. LSFG has a low procedural complexity, obtains precise and reproducible measurements and is therefore suitable to assess ocular perfusion.

The proposed study aims to evaluate optic nerve head blood flow and microcirculation in patients with idiopathic intracranial hypertension. For this purpose, optic nerve head blood flow will be examined in patients with IIH before and after therapy and additionally compared with healthy age- and sex-matched control subjects. In addition, other parameters will be measured, in particular retinal blood flow, retinal oxygen saturation and retinal neurovascular coupling.

• Study Type: Observational
• Enrollment (Estimated): 48

Contacts and Locations

• Study Contact: Name: Gerhard Garhöfer; Phone Number: +43 1 40400 29880; Email: gerhard.garhoefer@meduniwien.ac.at

Study Locations

• Austria
  • Vienna, Austria, 1090
    • Recruiting
    • Medical University of Vienna
    • Contact: Gerhard Garhöfer; Phone Number: +43 40400 29880; Email: gerhard.garhoefer@meduniwien.ac.at

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

A total of 48 patients will be included in the study:

• Group 1: 24 subjects with idiopathic intracranial hypertension
• Group 2: 24 age- and sex-matched control subjects

Description

Inclusion criteria for patients with idiopathic intracranial hypertension

• Men and Women aged ≥ 18 years
• Signed informed consent
• Newly diagnosed idiopathic intracranial hypertension or relapse of idiopathic intracranial hypertension
• Non-Smokers

Inclusion criteria for healthy age- and sex-matched control subjects

• Men and Women aged ≥ 18 years
• Signed informed consent
• Normal ophthalmic findings, unless the investigator considers an abnormality to be clinically irrelevant
• Normal findings in the medical history, unless the investigator considers an abnormality to be clinically irrelevant
• Non-Smokers

Exclusion criteria for patients with idiopathic intracranial hypertension and healthy age- and sex-matched control subjects:

• Blood donation in the three weeks preceding the study
• Symptoms of a clinically relevant illness in the three weeks preceding the study
• Ocular inflammation or infection within the last 3 months
• History or family history of epilepsy
• Diabetes mellitus type 1 or type 2
• History or known presence of other cerebral vascular diseases (e.g.: arteriovenous malformation, aneurysm, major artery stenosis or occlusion)
• History or known presence of intracranial infections (e.g.: meningitis)
• History or known presence of other neurological diseases (e.g.: brain tumor, hydrocephalus, degenerative diseases)
• Patients receiving corticosteroids or immunosuppressant therapy
• Pregnant or breast-feeding women
• Women of childbearing potential (neither menopausal, nor hysterectomized, nor sterilized) not using effective contraception

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Idiopathic intracranial hypertension (Group 1); 24 subjects with idiopathic intracranial hypertension	Other: Lumbar puncture and administration of medication; Patients with idiopathic intracranial hypertension will receive lumbar puncture and will be given medication to reduce intracranial pressure by neurologists. The lumbar puncture and the administration of medication are not part of this study, patients would also receive these without participating in the study.
Healthy control subjects (Group 2); 24 age- and sex-matched control subjects

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Optic nerve head blood flow	Change in optic nerve head blood flow in patients with idiopathic intracranial hypertension before and 6 months after therapy (LSFG).	Before the start of the therapy and 6 months after the start of the therapy

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Neurovascular coupling	Change in neurovascular coupling in patients with idiopathic intracranial hypertension before and 6 months after therapy (Dynamic Vessel Analyzer, IMEDOS, Jena, Germany)	Before the start of the therapy and 6 months after the start of the therapy
Retinal nerve fiber layer thickness	Change in retinal nerve fiber layer thickness in patients with idiopathic intracranial hypertension before and 6 months after therapy.	Before the start of the therapy and 6 months after the start of the therapy
Retinal and retinal layer thickness	Change in retinal and retinal layer thickness in patients with idiopathic intracranial hypertension before and 6 months after therapy (OCT).	Before the start of the therapy and 6 months after the start of the therapy
Retinal vessel density	Change in retinal vessel density in patients with idiopathic intracranial hypertension before and 6 months after therapy (OCT-A).	Before the start of the therapy and 6 months after the start of the therapy
Choroidal vascularity index (EDI-OCT)	Change in choroidal vascularity index (CVI is defined as the ratio of vascular luminal area (LA) to total choroidal area (TCA) and is presented as a percentage) in patients with idiopathic intracranial hypertension before and 6 months after therapy (EDI-OCT).	Before the start of the therapy and 6 months after the start of the therapy
Retinal vessel diameter	Change in retinal vessel diameter (µm) in patients with idiopathic intracranial hypertension before and 6 months after therapy (retinal oximetry).	Before the start of the therapy and 6 months after the start of the therapy
Optic nerve head blood flow	Change in optic nerve head blood flow in patients with idiopathic intracranial hypertension before and 6 months after therapy (LDF).	Before the start of the therapy and 6 months after the start of the therapy
Retinal oxygen extraction	Change in retinal oxygen extraction in patients with idiopathic intracranial hypertension before and 6 months after therapy (LSFG, retinal oximetry).	Before the start of the therapy and 6 months after the start of the therapy
Ocular perfusion pressure and arterial blood pressure	Change in ocular perfusion pressure and arterial blood pressure in patients with idiopathic intracranial hypertension before and 6 months after therapy.	Before the start of the therapy and 6 months after the start of the therapy
Retinal oxygen saturation	Retinal oxygen saturation (SO2) in patients with idiopathic intracranial hypertension before and 6 months after therapy (retinal oximetry).	Before the start of the therapy and 6 months after the start of the therapy
Choroidal thickness (EDI-OCT)	Change in choroidal thickness (µm) in patients with idiopathic intracranial hypertension before and 6 months after therapy (EDI-OCT).	Before the start of the therapy and 6 months after the start of the therapy

Collaborators and Investigators

• Sponsor: Medical University of Vienna

Publications and helpful links

General Publications

• Miller MM, Chang T, Keating R, Crouch E, Sable C. Blood flow velocities are reduced in the optic nerve of children with elevated intracranial pressure. J Child Neurol. 2009 Jan;24(1):30-5. doi: 10.1177/0883073808321050.
• Markey KA, Mollan SP, Jensen RH, Sinclair AJ. Understanding idiopathic intracranial hypertension: mechanisms, management, and future directions. Lancet Neurol. 2016 Jan;15(1):78-91. doi: 10.1016/S1474-4422(15)00298-7. Epub 2015 Dec 8.
• Pruckner P, Mitsch C, Macher S, Krajnc N, Marik W, Novak K, Wober C, Pemp B, Bsteh G. The Vienna idiopathic intracranial hypertension database-An Austrian registry. Wien Klin Wochenschr. 2024 Jan;136(1-2):32-39. doi: 10.1007/s00508-023-02252-x. Epub 2023 Aug 31.
• Wang MTM, Bhatti MT, Danesh-Meyer HV. Idiopathic intracranial hypertension: Pathophysiology, diagnosis and management. J Clin Neurosci. 2022 Jan;95:172-179. doi: 10.1016/j.jocn.2021.11.029. Epub 2021 Dec 17.
• Sugiyama T, Araie M, Riva CE, Schmetterer L, Orgul S. Use of laser speckle flowgraphy in ocular blood flow research. Acta Ophthalmol. 2010 Nov;88(7):723-9. doi: 10.1111/j.1755-3768.2009.01586.x.
• Tamaki Y, Araie M, Tomita K, Nagahara M, Tomidokoro A, Fujii H. Real-time measurement of human optic nerve head and choroid circulation, using the laser speckle phenomenon. Jpn J Ophthalmol. 1997 Jan-Feb;41(1):49-54. doi: 10.1016/s0021-5155(96)00008-1.

Study record dates

Study Major Dates

• Study Start (Actual): May 28, 2024
• Primary Completion (Estimated): May 28, 2026
• Study Completion (Estimated): August 31, 2026

Study Registration Dates

• First Submitted: June 12, 2024
• First Submitted That Met QC Criteria: August 7, 2024
• First Posted (Actual): August 9, 2024

Study Record Updates

• Last Update Posted (Actual): August 30, 2024
• Last Update Submitted That Met QC Criteria: August 29, 2024
• Last Verified: August 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Hypertension; Intracranial Hypertension; Pseudotumor Cerebri
• Other Study ID Numbers: OPHT-241123

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No