- Case Presentation:
- A 46-year-old man with a 2-week history of blurred vision in the right lower visual field of both eyes.
- Symptoms included colored images around the dark area, lethargy, polydipsia, and mild headaches.
- Medical history: dyslipidemia, treated with rosuvastatin.
- Ophthalmological examination: normal visual acuity, pupils, color vision, and fundus.
- Visual field testing revealed right homonymous hemianopia denser inferiorly.
- Initial neuroimaging (CT and MRI) appeared normal, but further review showed subtle abnormal T2/FLAIR hyperintensity in the left occipital cortex.
- Diagnosis:
- Homonymous hemianopia secondary to nonketotic hyperglycemia (NKH).
- Management:
- Blood glucose levels were measured, revealing severe hyperglycemia (473.87 mg/dL) and elevated hemoglobin A1C (11.8%).
- The patient was admitted for blood glucose optimization.
- Intravenous lorazepam stopped the colored images around the visual field defect.
- Blood glucose normalized with insulin, metformin, and gliclazide.
- Visual field defect resolved after 4 days, and repeated testing at 3 months was normal.
- Discussion:
- Homonymous hemianopia can result from various retrochiasmal visual pathway lesions.
- NKH can cause neurologic manifestations, including seizures and homonymous hemianopia.
- Neuroimaging in NKH typically shows cortical hyperintensity on T2-weighted and FLAIR MRI sequences.
- Recognition of hyperglycemia as the cause is crucial for appropriate management, primarily involving insulin therapy and hydration.
- Maintenance antiepileptic therapy is not necessary as the seizures are provoked by hyperglycemia.
- Patient Outcome:
- Successful resolution of symptoms with appropriate treatment.
- Visual field defect resolved, and no recurrence was noted at follow-up.
- Key Points:
- Consider hyperglycemia in patients with homonymous hemianopia and normal neuroimaging.
- Prompt treatment of hyperglycemia can reverse visual field defects and other neurologic symptoms.
- Avoid unnecessary investigations by recognizing the ictal etiology of visual field defects in hyperglycemia.