Chorioretinopathy presenting as bitemporal hemianopia.

INTRODUCTION: Bitemporal hemianopia is usually caused by chiasmal pathology. Rarely, chorioretinal lesions may develop symmetrically in both eyes and mimic chiasmopathy.

METHODS: This case series included three patients who presented to a tertiary neuro-ophthalmology centre with bitemporal hemianopic defects between 2021 and 2023 and were subsequently diagnosed with bilateral chorioretinopathy. All patients received comprehensive examinations from a fellowship-trained neuro-ophthalmologist and uveitis specialist to rule out other causes of visual dysfunction.

RESULTS: Three males aged 64, 62, and 72 years were included. All patients showed bitemporal hemianopic defects crossing the vertical midline on automated perimetry and binasal thinning of the macular ganglion cell complex on spectral-domain optical coherence tomography (OCT). Fundus autofluorescence (FAF) showed classical features of acute zonal occult outer retinopathy (AZOOR) in two patients and central serous chorioretinopathy (CSCR) in another. AZOOR diagnosis was preceded by neuroimaging in both cases, whereas the patient with CSCR had longstanding, electroretinography-confirmed lesions and did not require neuroimaging. Fundus appearance and visual field defects remained stable in all patients across 3-6 months of follow-up.

CONCLUSIONS: Bilateral chorioretinopathy should be considered in the differential diagnosis of bitemporal hemianopia in specific cases, including when visual field defects cross the vertical midline and when neuroimaging fails to reveal chiasmal pathology. FAF and macular OCT have high diagnostic yield as initial investigations.