Chronic relapsing inflammatory optic neuropathy misdiagnosed as intermittent angle closure: a diagnostic challenge.

A woman in her 40 s presented with recurrent retro-orbital pain over several years, initially attributed to migraine. Later, she was diagnosed with glaucoma in the context of suspected intermittent angle closure. Despite controlled intraocular pressure (IOP) with topical pressure-lowering therapy, progressive visual loss persisted.Optical coherence tomography showed diffuse retinal nerve fibre layer (RNFL) thinning, and visual fields demonstrated severe defects. However, pronounced optic disc pallor, rapid progression despite IOP control and diffuse rather than sectorial RNFL loss raised suspicion of an alternative diagnosis. Visual evoked potentials demonstrated delayed P100 latency, and MRI confirmed inflammatory changes of the optic nerve.High-dose systemic corticosteroids led to marked improvement, with relapse following its withdrawal, confirming steroid dependency. Chronic relapsing inflammatory optic neuropathy was the diagnosis, and immunosuppressive therapy was initiated with subsequent sustained visual recovery.This case highlights the importance of considering alternative diagnoses in atypical glaucoma presentations.