A 46-year-old man presented with a 2-week history of a persistent blurred area in his right lower visual field of both eyes. He noticed colors surrounding the dark area that lasted 2 to 3 minutes at a time and occurred multiple times per day. His medical history was significant for dyslipidemia for which he took rosuvastatin. He also reported feeling lethargic, with polydipsia and a dull mild holocephalic headache during this period. Ophthalmological examination revealed a visual acuity of 20/20 OU, pupils were equal and reactive to light with no relative afferent pupillary defect, and color vision was normal. Dilated fundus examination was normal. Humphrey 24-2 Swedish interactive threshold algorithm fast visual field testing revealed a right homonymous hemianopia denser inferiorly (Figure, A). An urgent noncontrast computed tomography (CT) scan of the head was obtained and was normal (Figure, B). Magnetic resonance imaging (MRI) of the brain was initially reported as normal but revealed subtle abnormal T2/fluid-attenuated inversion recovery hyperintensity involving the left occipital cortex after further review (Figure, B).
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Homonymous hemianopia secondary to nonketotic hyperglycemia
B. Measure blood glucose levels
Homonymous visual field defects occur from processes affecting the contralateral retrochiasmal visual pathways. Neuroimaging is indicated to identify a potential culprit lesion of which the etiology is broad and includes neoplastic, vascular, trauma, and postsurgical causes.1 It is a diagnostic dilemma when a patient presents with a homonymous visual field defect without an obvious abnormality on neuroimaging. In this case, measuring blood glucose levels to investigate hyperglycemia would be the next best step considering the patient’s reported lethargy and polydipsia (choice B). Measure C-reactive protein level and erythrocyte sedimentation rate (choice A) would not be the preferred option since a vasculitis and secondary infarct was not supported by the history or neuroimaging findings.2 A lumbar puncture (choice C) was not recommended as the next step since the presentation was not consistent with a meningeal process based on the history, examination, and MRI findings. Given his CT and MRI already ruled out vascular and neoplastic causes, magnetic resonance angiography (choice D) was unlikely to add any additional information and would not be the next recommended step.
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CME Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships. If applicable, all relevant financial relationships have been mitigated.
Corresponding Author: Jonathan A. Micieli, MD, CM, Kensington Vision and Research Centre, 340 College St, Ste 501, Toronto, ON M5T 3A9, Canada (email@example.com).
Published Online: November 4, 2021. doi:10.1001/jamaophthalmol.2021.3356
Conflict of Interest Disclosures: None reported.
Additional Contributions: We thank the patient for granting permission to publish this information.
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