Sudden visual loss and hypereosinophilia: A case of eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis is a systemic vasculitis of small- and medium-sized blood vessels. The disease can manifest itself variably, with the most commonly affected organs including the lungs, sinuses, and peripheral nervous system. Ocular involvement is rare, and the visual prognosis is generally poor. To date, only a few cases have been published describing the ocular manifestations of eosinophilic granulomatosis with polyangiitis. Given the rarity of these complications, diagnosis can be difficult. We report the case of a 60-year-old woman with a history of asthma, sinusitis, and peripheral neuropathy, who presented to our hospital with sudden loss of vision in her right eye. After referral to an ophthalmologist, a diagnosis of central retinal artery occlusion of the right eye was made. Laboratory tests showed hypereosinophilia and mild positivity for antinuclear antibodies. Imaging revealed multiple micronodules in the lung and sinusopathy. Diagnostic tests for stroke, malignancy, and infectious diseases were negative. Based on laboratory, clinical, and imaging data, the patient was diagnosed with eosinophilic granulomatosis with polyangiitis. Treatment with glucocorticoids and cyclophosphamide was started to induce disease remission. The patient achieved a clinical response to treatment with sustained normalisation of peripheral eosinophil counts and maintenance therapy with mepolizumab was initiated. Unfortunately, no improvement in visual function was observed. In patients with sudden vision loss and hypereosinophilia, eosinophilic granulomatosis with polyangiitis should be suspected. Timely diagnosis is essential to initiate appropriate treatment. However, the effect of systemic treatment on improving patients' visual function is still unclear.