Retinal Neuro-vascular Coupling in Patients With Non-arteritic Anterior Ischemic Optic Neuropathy

Inclusion criteria for healthy subjects: * Men and women aged over 18 years * Non-smokers * Normal findings in the medical history unless the investigator considers an abnormality to be clinically irrelevant * Normal ophthalmic findings, ametropy \< 6 Dpt. Inclusion criteria for patients with NAION: * Men and women aged over 18 years * History of NAION in one eye * Normal ophthalmic findings, ametropy \< 6 Dpt. * Adequate visual acuity to allow participation in the ocular blood flow measurements * A potential participant has to be on stable doses of all medications he/she is taking because of consisting illnesses according to medical history for at least 30 days prior inclusion, if considered relevant by the investigator. Any of the following will exclude a healthy subject from the study: * Current ocular disease or history of NAION * Presence or history of a severe medical condition as judged by the clinical investigator * Untreated Arterial hypertension * History or family history of epilepsy * Presence of any abnormalities preventing reliable measurements in the study eye as judged by the investigator * Best corrected visual acuity \< 0.5 Snellen * Ametropy ≥ 6 Dpt * Pregnancy or planned pregnancy * Alcoholism or substance abuse Any of the following will exclude a patient from the study: * Presence or history of a severe medical condition other NAION as judged by the clinical investigator * Untreated Arterial hypertension * History or family history of epilepsy * Presence of any abnormalities preventing reliable measurements in the study eye as judged by the investigator * Best corrected visual acuity \< 0.5 Snellen in the non-affected eye * Ametropy ≥ 6 Dpt * Pregnancy, planned pregnancy * Alcoholism or substance abuse