Idiopathic Intracranial Hypertension Treatment Trial (IIHTT)
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ClinicalTrials.gov Identifier: NCT01003639 |
Recruitment Status :
Completed
First Posted : October 29, 2009
Results First Posted : December 12, 2018
Last Update Posted : December 12, 2018
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Condition or disease | Intervention/treatment | Phase |
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Idiopathic Intracranial Hypertension | Drug: Acetazolamide Drug: Placebo Behavioral: Formal weight loss counselling program | Phase 2 Phase 3 |

Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 165 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Treatment |
Official Title: | A Multicenter, Double-blind, Randomized, Placebo-controlled Study of Weight-Reduction and/or Low Sodium Diet Plus Acetazolamide vs Diet Plus Placebo in Subjects With Idiopathic Intracranial Hypertension With Mild Visual Loss |
Study Start Date : | January 2010 |
Actual Primary Completion Date : | June 2013 |
Actual Study Completion Date : | January 2014 |

Arm | Intervention/treatment |
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Active Comparator: Acetazolamide
Acetazolamide given in escalating doses
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Drug: Acetazolamide
Subjects will begin with four 250 mg tablets daily. Tablets will be divided among two doses, taken with meals. Beginning on day 7, subjects will increase the dose by 1 pill every week until 16 tablets daily is reached (4 grams acetazolamide or placebo) or side effects prohibit increasing the dosage further. Thus, subjects who are able to tolerate the study medication will reach the maximum dose by day 84.
Other Names:
Behavioral: Formal weight loss counselling program Teleconference, web-based from central location, using site visits and subject self-assessment tools
Other Names:
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Placebo Comparator: Sugar pill
Given in escalating "dose" (number of pill)
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Drug: Placebo
Subjects will begin with four tablets daily. Tablets will be divided among two doses, taken with meals. Beginning on day 7, subjects will increase the dose by 1 pill every week until 16 tablets daily is reached (4 grams acetazolamide or placebo) or side effects prohibit increasing the dosage further. Thus, subjects who are able to tolerate the study medication will reach the maximum dose by day 84.
Other Names:
Behavioral: Formal weight loss counselling program Teleconference, web-based from central location, using site visits and subject self-assessment tools
Other Names:
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- Mean Change in Perimetric Mean Deviation [ Time Frame: base line and 6 months ]Treatment Effects on the Primary Outcome Variable, Mean change From Baseline to Month 6 in Perimetric Mean Deviation (PMD) in the Study Eye. Perimetric mean deviation is a measure of global visual field loss (mean deviation from age-corrected normal values), with a range of 2 to -32 dB; larger negative values indicate greater vision loss.
- Mean Change of Papilledema Grade on Fundus Photography [ Time Frame: Baseline and 6 Months ]Mean change at month 6 as compared to baseline. Frisén papilledema grade is an ordinal scale that uses ocular fundus features to rate the severity of papilledema; grade 0 indicates no features of papilledema and grade 5 indicates severe papilledema.
- Visual Function Questionnaire (VFQ-25) [ Time Frame: baseline ]Visual Function Questionnaire (VFQ-25) total score, VFQ-25 10-item neuro-ophthalmic supplement total score: 0-100 (higher scores indicate better quality of life)
- Visual Acuity (No. of Correct Letters) [ Time Frame: Baseline ]

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Ages Eligible for Study: | 18 Years to 60 Years (Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Diagnosis of IIH by modified Dandy criteria Signs and symptoms of increased intracranial pressure Absence of localizing findings on neurologic examination Absence of deformity, displacement, or obstruction of the ventricular system and otherwise normal neurodiagnostic studies, except for evidence of increased cerebrospinal fluid pressure (>200 mm water). Abnormal neuroimaging except for empty sella turcica, optic nerve sheath enlargement, and smooth-walled non flow-related venous sinus stenosis or collapse106 should lead to another diagnosis Awake and alert No other cause of increased intracranial pressure present
- Diagnosis of IIH for 6 weeks or less
- Age 18 to 60 years at time of diagnosis
- Reproducible visual loss present on automated perimetry (in eye with greatest loss)
- Average PMD -2 dB up to -5 dB in the worst eye
- Presence of bilateral papilledema
- Able to provide informed consent
- Women of child-bearing potential must use an acceptable form of birth control during the intervention phase of the study. Acceptable forms include oral contraceptives, transdermal contraceptives,
Exclusion Criteria:
- Total treatment of IIH of more than two weeks (except for acetazolamide which is limited to 1 week). For every day on treatment there must be a one-day washout period.
- Previous surgery for IIH including optic nerve sheath fenestration, CSF shunting procedures, subtemporal decompression and venous stenting
- Previous gastric bypass surgery
- Abnormalities on neurologic examination aside from papilledema and its related visual loss or VI nerve paresis
- Abnormal CT or MRI scan (intracranial mass, hydrocephalus, dural sinus thrombus or arteriovenous malformation) other than empty sella, unfolded optic nerve sheaths, flattened sclera, or smooth- walled venous stenosis
- CSF pressure less than 200 mm water (patients may have repeat CSF pressure measurements if the first is normal or no opening pressure obtained)
- Abnormal CSF contents: increased cells: > 5 cells, elevated protein:
> 45 mg%, low glucose: < 30 mg% (If the lumbar puncture produces a cell count compatible with a traumatic needle insertion, the patient does not need to be excluded if the CSF WBC after correction is 5 wbc/mm3 or less- see Operations Manual for calculation) 8. Intraocular pressure currently > 28 mm Hg or > 30 mm Hg at any time in the past 9. Refractive error > +/- 6.00 sphere or > +/- 3.00 cylinder in either eye with the following exceptions: Subjects with myopia of >-6.00 D sphere but less than or equal to - 8.00 D sphere are eligible if 1)there are no abnormalities on ophthalmoscopy or fundus photos related to myopia that are associated with visual loss (such as staphyloma, retinal thinning in the posterior pole or more than mild optic disc tilt), and 2) the subject wears a contact lens for all perimetry examinations with the appropriate correction. If either the Site Investigator or the PRC director (or his designate) decides there are optic fundus abnormalities of myopia that are associated with visual loss, then 9. Subjects with hyperopia of > +6.00 D but less than or equal to
- 8.00 D sphere are eligible if 1) there is an unambiguous characteristic halo of peripapillary edema as opposed to features of a small crowded disc or other hyperopic change related to visual loss determined by the site investigator or the PRC director (or his designate) and 2) the subject wears a contact le 10. Other disorders causing visual loss except for refractive error and amblyopia including cells in the vitreous or iritis 11. Optic disc drusen on exam or in previous history 12. Presence of diagnosed untreated obstructive sleep apnea 13. Inability to provide reliable and reproducible visual field examination (failure to maintain fixation using an eye monitoring device, more than 15% false positive errors) 14. Abnormal blood work-up indicating a medical or systemic condition associated with raised ICP 15. Study blood results showing severe anemia, leukopenia or thrombocytopenia, renal failure, or hepatic disease, based on the Site Investigator's judgment 16. Type I diabetes or the presence of diabetic retinopathy 17. Exposure to a drug, substance or disorder that has been associated with elevation of intracranial pressure within 2 months of diagnosis such as lithium, vitamin A, various cyclines (see table in Operations Manual for conditions and drugs) 18. Other condition requiring diuretics, oral, I.V. or injectable steroids or other pressure lowering agents including topiramate (nasal, inhaled, or topical steroids are allowed since the systemic effects are small) 19. Presence of a medical condition such as renal stones that would contraindicate use of the study drug (acetazolamide) 20. Pregnancy or unwillingness for subject of childbearing potential to use contraception during the first year of the study 21. Breastfeeding mothers are excluded from participation unless willing to discontinue breastfeeding by the baseline visit 22. Presence of a physical, mental, or social condition likely to affect follow-up (drug addiction, terminal illness, no telephone, homeless) 23. Anticipation of a move from the site area within six months and unwillingness to return for follow-up at an IIHTT study site 24. Allergy to pupil dilating drops or narrow angles precluding safe dilation

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01003639

Study Director: | Michael Wall, MD | University of Iowa |
Publications of Results:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: | St. Luke's-Roosevelt Hospital Center |
ClinicalTrials.gov Identifier: | NCT01003639 |
Other Study ID Numbers: |
NORDIC01 1U10EY017281-01A1 ( U.S. NIH Grant/Contract ) 1U10EY017387-01A1 ( U.S. NIH Grant/Contract ) |
First Posted: | October 29, 2009 Key Record Dates |
Results First Posted: | December 12, 2018 |
Last Update Posted: | December 12, 2018 |
Last Verified: | November 2018 |
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