Differing presenting features of idiopathic intracranial hypertension in the UK and US

• Type of Material: Article
• Authors: R. J. Blanch, Emory University; C. Vasseneix, Emory University; A. Liczkowski, University of Birmingham; A. Yiangou, University of Birmingham; A. Aojula, University of Birmingham; J. A. Micieli, Emory University; S. P. Mollan, University Hospital Birmingham NHS Trust; Nancy Newman, Emory University; Valerie Biousse, Emory University; Beau Bruce, Emory University; A. Sinclair, University of Birmingham
• Language: English
• Date: 2019-06-01
• Publisher: Nature Publishing Group
• Publication Version: Final Published Version
• Copyright Statement: © The Royal College of Ophthalmologists 2019.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1038/s41433-019-0359-5
• Title of Journal or Parent Work: Eye: The Scientific Journal of The Royal College of Ophthalmologists
• Volume: 33
• Issue: 6
• Start Page: 1014
• End Page: 1019
• Grant/Funding Information: The Emory cohort study was supported in part by an unrestricted departmental grant (Department of Ophthalmology) from Research to Prevent Blindness, Inc., New York, and by NIH/NEI core grant P30-EY006360 (Department of Ophthalmology).; NJN is a recipient of the Research to Prevent Blindness Lew R. Wasserman Merit Award.; VB received research support from NIH/PHS (UL1-RR025008).; IH:Life database is funded by the Healthcare Quality Improvement Partnership (HQIP) and IIHUK, (registered patient charity in England and Wales: 1143522).; CV is the recipient of the Philippe Foundation, Inc. grant.; AS is funded by an NIHR Clinician Scientist Fellowship (NIHR-CS-011-028) and by the Medical Research Council, UK (MR/K015184/1).
• Keywords: Clinical characteristics; Pressure; Life Sciences & Biomedicine; Ophthalmology; Pseudotumor cerebri; Population; Obesity; Prevalence; Science & Technology
• Research Categories: Health Sciences, Opthamology; Health Sciences, Public Health; Biology, Neuroscience; Health Sciences, Nutrition

Abstract

Aim: Demographic factors potentially influencing the presentation and severity of idiopathic intracranial hypertension (IIH) in the US vs. UK populations include obesity and ethnicity. We aimed to compare the presenting features of IIH between populations in the UK and US tertiary referral centres, to assess what population differences exist and whether these cause different presentations and impact on visual function. Methods: Clinical data were collected on 243 consecutive UK IIH patients and 469 consecutive US IIH patients seen after 2012 in two tertiary centres. Visual function was defined as severe visual loss when Humphrey visual field mean deviation was <−15 dB, when Goldmann visual fields showed constriction or when visual acuity was <20/200. Results: US patients were more commonly of self-reported black race (58.9% vs. 7.1%) than UK patients, but had a similar mean body mass index (38.3 ± 0.63kg/m2 UK vs. 37.7 ± 0.42kg/m2 US; p = 0.626). The UK cohort had lower presenting Frisén grade (median 1 vs. 2; p < 0.001) and severe visual loss less frequently (15.4% vs. 5%; p = 0.014), but there was no difference in mean cerebrospinal fluid-opening pressure (CSF-OP) (35.8 ± 0.88cmH2O UK vs. 36.3 ± 0.52cmH2O US; p = 0.582). African Americans had poorer visual outcomes compared with US whites (19.4% vs. 10% severe visual loss; p = 0.011). Visual function was weakly associated with CSF-OP (R2 = 0.059; p = 0.001), which was similar between UK and US patients. Conclusions: The UK and the US cohorts had a similar average presenting BMI. However, the worse presenting visual function in the US IIH cohort was partially attributable to differences in the black populations in the two countries.