Visual Involvement in Giant Cell Arteritis

Inclusion Criteria: * For GCA group: * Patients older than 18 years with clinically suspected or confirmed gigantocellular arteritis. * Newly found visual involvement with suspected or confirmed correlation with vasculitis. * Ability to express valid consent to study enrolment. * For control group: * Patients older than 18 years with the ability to express valid consent to study enrolment. * Newly diagnosed acute visual impairment with GCA phenotypes (e.g. AION, CRAO) but without any correlation with vasculitis aetiology. Exclusion Criteria: * Pre-existing ophthalmological pathologies that may modify best visual acuity and/or alter ophthalmological semeiotics. * Concomitant active viral, bacterial, fungal and parasitic infections, including active or latent tuberculosis treated for less than 4 weeks and HIV, hepatitis C virus (HCV) /hepatitis B virus (HBV) infections, involving the eyes and orbital cavities. * Concomitant systemic inflammations not attributable to GCA (inflammatory diseases in treatment-free remission are not excluded). * Any other condition judged by the investigators to be a contraindication of eligibility