Neuroretinitis is relatively rare. It refers to the triad of subacute visual loss, optic disc swelling and a macular star (figure 1), often in association with cells in the vitreous.^1–4 An illustrative case is presented in this issue of Practical Neurology.⁵ The macular star typically takes 1–2 weeks to develop, meaning that it is usually not possible to make the diagnosis when the patient first presents. At that time, the condition may resemble, and be misdiagnosed as, idiopathic demyelinating optic neuritis (IDON) with the potential for inappropriate use of multiple sclerosis disease-modifying agents or, alternatively, failure to treat a preventable cause of visual loss. It is therefore important that neurologists are aware of this condition.⁶

The radial arrangement of the hard exudates in a macular star arises from the anatomy of the outer plexiform layer of the retina, and not all macular stars are perfectly formed.⁵ The combination of optic disc oedema with a macular star² can occur in conditions other than neuroretinitis, the most frequent being hypertensive retinopathy (see table 1). Most masqueraders …