CRP and temporal arteritis: Thus, any patient over the age of 55 years who presents with a history of amaurosis fugax, diplopia, or visual loss and has clinical findings of arteritic anterior ischemic optic neuropathy, central retinal artery occlusion, cilioretinal artery occlusion, or posterior ischemic optic neuropathy should be suspected of having GCA and have erythrocyte sedimentation rate and CRP level evaluations done on an emergency basis, regardless of having systemic symptoms of GCA.