Ophthalmic manifestations of giant cell arteritis.

GCA, the most common systemic arteritis, affects medium-sized and larger extradural arteries that have the internal elastic lamina. Involvement of the ophthalmic artery and its branches results in visual loss, which is often complete but is usually painless. Visual loss may be monocular or binocular developing simultaneously or sequentially. Rarely, it stems from occipital lobe infarct that result in homonymous hemianopia, a visual field defect involving the two identical halves (right or left) of the visual fields of both eyes. Visual hallucinations and diplopia are less common. All visual symptoms, including those that are transient, require urgent ophthalmological evaluation and treatment with high-dose glucocorticoids to avoid permanent visual loss.