Neuroimaging in normal tension glaucoma: to scan or not to scan?

Abstract

AbstractPurposeTo determine the frequency, yield and possible cost implications of brain imaging in patients with normal tension glaucoma (NTG).MethodsRetrospective case series of patients from a single centre in West London who underwent brain imaging as part of diagnostic workup for NTG between January 2018 and May 2021. The main outcome measures included the frequency of requests, and diagnostic yield for relevant and incidental findings. Secondarily, we examined the prevalence of NTG risk factors and whether they were documented in patient notes.ResultsNotes from 496 patients with NTG were analysed. Among them, 47 (9%) had an imaging scan requested by their ophthalmologist. Only 1 patient (2%) was found to have an intracranial lesion compressing the optic chiasm. Other incidental findings included 1 meningioma (2%), 1 pituitary cyst (2%), and 12 patients showing small vessel disease (26%). The number needed to test for one positive finding was 50 (assuming no tumours were missed). The estimated cost of the scans requested was £64 719. However, the costs of treating a brain tumour can range from £13 200 to £180 000 annually, depending on the grade1. Based on these findings and the literature review, we propose a new guideline based to help clinicians in the evaluation of NTG patients to improve diagnostic yield.ConclusionsIntracranial compressive lesions are an important differential diagnosis to NTG. However, a more judicious approach to the use of neuroimaging is required.Bibliography1. Macmillan Cancer Support. Routes from Diagnosis: The most detailed map of cancer survivorship yet (2014), Pg 46 available at: https://www. macmillan.org.uk/_images/Routesfromdiagnosisreport_tcm9‐265651.pdf.