Characterisation and Visual Outcomes of Fulminant Idiopathic Intracranial Hypertension: A Narrative Review

Prediction of Poor Visual Outcomes at Idiopathic Intracranial Hypertension Diagnosis Using a Supervised Machine Learning Algorithm

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a vision-threatening disorder mainly affecting women of a reproductive age. Prompt diagnosis and intervention are vital to prevent vision loss, but validated tools to predict visual outcomes are lacking. The purpose of this study was to create a machine learning algorithm predicting poor visual outcomes at the time that the diagnosis of IIH is established, and stratifying risk among those with and without poor visual acuity at presentation.

METHODS

Using electronic health records, a retrospective cohort study was conducted between June 1, 2012 and September 30, 2023. Any patient aged 0-70 years who was diagnosed with IIH and met the revised diagnostic criteria was included in the analysis. In total, 391 patients with IIH had final outcomes available and were included in this analysis. Final visual outcomes were reported between 3 months and 1 year after diagnosis. Poor visual outcomes served as the model outcome and was defined as a visual field mean deviation (VFMD) worse than -7 dB or a visual acuity of 20/80 or worse. Both logistic regression and decision trees were used to build predictive models. Models were evaluated using multiple parameters including accuracy, sensitivity, specificity, and area under the curve. The best performing models were validated using a k-fold cross-validation.

RESULTS

The decision tree models performed the best and 4 prognostic risk groups were created: critical, high, medium, and low. In the critical risk group, patients who had both high baseline VFMD (worse than -12.59 dB) and identified as non-White had a poor visual outcome risk of 92.6%. A baseline VFMD worse than -9.1 dB resulted in a critical risk of a poor visual outcome at 69.8%. Any patient with a baseline VFMD better than -3.39 dB had a risk of a poor visual outcome at 1.04%.

CONCLUSIONS

Our study provides clinicians with valuable prognostic markers to assist in identifying patients who are at critical risk for significant vision loss. Patients with a VFMD worse than -9.1 dB have a critical risk of a poor visual outcome, and this further increased if they identified as a minority patient.

Managing idiopathic intracranial hypertension in the eye clinic

Idiopathic intracranial hypertension (IIH) is a neuro-ophthalmological condition characterised by a raised intracranial pressure and papilloedema that causes disabling headaches. The main risk factors of female sex and living with obesity have been known for some time, however the knowledge of the underlying pathophysiology is evolving. Papilloedema can impact the visual function, and the majority of people are offered acetazolamide. Those with sight threatening disease need urgent management, though there is little high quality evidence to recommend any particular surgical intervention. Headache treatment is an unmet clinical need and simple medication overuse advice has the potential to reduce the chronification of migraine-like headaches. IIH is emerging as a systemic metabolic disease distinct from people living with obesity alone. While weight loss is the main stay of disease modifying therapy this is challenging to access and many healthcare professionals that manage the condition have no formal training or accessible pathways for weight management. The aim of this "how to do it" article is to present the latest advances in knowledge of IIH that we pragmatically included in routine clinical care for people living with the condition.