Vision Threatening Raised Intracranial Pressure Associated with Recreational Nitrous Oxide Use

Nitrous oxide is used as an anaesthetic and analgesic agent in the medical setting and is known to cause raised intracranial pressure. The use of nitrous oxide recreationally for the drug’s euphoric and relaxant properties has been linked to multiple neurological and psychiatric sequelae including neuropathy, myelopathy, and psychosis. We describe a case of a young person who declared heavy nitrous oxide use resulting in vision-threatening papilloedema secondary to raised intracranial pressure. He underwent emergency lumbar drainage alongside high-dose acetazolamide and parenteral vitamin B12 injections. To our knowledge, there have yet to be other reports of cases where heavy nitrous oxide use has caused secondary pseudotumor cerebri syndrome

Does a Healthy Weight Body Mass Index at Onset of Idiopathic Intracranial Hypertension Change the Outcomes? A United Kingdom Prospective Cohort Study

Idiopathic intracranial hypertension (IIH) predominantly affects reproductive-aged females with obesity. However, the prevalence and impact of a healthy weight body mass index (BMI) at disease presentation is not known. This study aimed to evaluate the visual and headache outcomes stratified by the presenting BMI. This was a longitudinal prospective cohort study (IIH Life) based on a tertiary neuro-ophthalmology IIH service, University Hospitals Birmingham NHS Trust, United Kingdom, recruiting consecutive patients living with IIH between 2012 and 2021. Those with a presenting BMI were included. The outcome measures included visual outcomes of LogMAR visual acuity, Humphrey visual field perimetric mean deviation (PMD), optical coherence tomography (OCT) measurements, and headache outcomes of frequency, severity, and Headache Impact Test-6 score. Three hundred seventy-five people with IIH and a documented baseline BMI. About 3.7% of the entire cohort had a healthy weight BMI at IIH presentation and 15.5% BMI < 30 kg/m2. The baseline PMD was worse in patients without obesity; however, OCT papilloedema measures were similar. The presence of obesity was associated with a small but significant greater worsening in visual acuity but slower macular ganglion cell layer loss. There was no impact on PMD or papilloedema prognosis related to baseline obesity. The headache outcomes showed heterogeneity, with worse baseline headache frequency in patients with obesity. No BMI group was associated with worse headache outcomes. Patients with a healthy weight BMI or those without obesity at baseline make up a small proportion of IIH patients. BMI at presentation does not appear to influence long-term visual or headache outcomes

Building trust in real-world data: lessons from INSIGHT, the UK's health data research hub for eye health and oculomics

PURPOSE OF REVIEW: In this review, we consider the challenges of creating a trusted resource for real-world data in ophthalmology, based on our experience of establishing INSIGHT, the UK's Health Data Research Hub for Eye Health and Oculomics. RECENT FINDINGS: The INSIGHT Health Data Research Hub maximizes the benefits and impact of historical, patient-level UK National Health Service (NHS) electronic health record data, including images, through making it research-ready including curation and anonymisation. It is built around a shared 'north star' of enabling research for patient benefit. INSIGHT has worked to establish patient and public trust in the concept and delivery of INSIGHT, with efficient and robust governance processes that support safe and secure access to data for researchers. By linking to systemic data, there is an opportunity for discovery of novel ophthalmic biomarkers of systemic diseases ('oculomics'). Datasets that provide a representation of the whole population are an important tool to address the increasingly recognized threat of health data poverty. SUMMARY: Enabling efficient, safe access to routinely collected clinical data is a substantial undertaking, especially when this includes imaging modalities, but provides an exceptional resource for research. Research and innovation built on inclusive real-world data is an important tool in ensuring that discoveries and technologies of the future may not only favour selected groups, but also work for all patients

Managing idiopathic intracranial hypertension in pregnancy: practical advice

Idiopathic intracranial hypertension (IIH) is more common in women of reproductive age who have obesity, yet there is little information on its management specifically in pregnancy. Women with IIH should plan their pregnancy including discussing contraception before pregnancy, recognising that hormonal contraceptives are not contraindicated. Potentially teratogenic medications including acetazolamide and topiramate are not recommended during pregnancy or in those with immediate plans to conceive; prescribing acetazolamide in pregnancy must only follow discussion with the patient and their obstetrician. Ideally, patients should aim to achieve disease remission or control before pregnancy, through optimising their weight. Although weight gain is expected in pregnancy, excessive weight gain may exacerbate IIH and increase maternal and fetal complications; evidence-based recommendations for non-IIH pregnancies may help in guiding optimal gestational weight gain. The vast majority of women with IIH can have a normal vaginal delivery, with spinal or epidural anaesthesia if needed, provided the papilloedema is stable or the IIH is in remission