LSFG in Patients With Normal Tension Glaucoma Tension Glaucoma

Inclusion Criteria: * Caucasian men and women aged over 50 years * Subject is generally healthy with no current significant or a history of a significant neurological, cardiovascular, pulmonary (including asthma), hepatic, metabolic, rheumatic, autoimmune, hematological or renal disorder, as determined by the investigator's clinical judgment through collection of medical history and performance of a physical examination. A significant disorder is defined as a disease or medical condition associated with impaired health status, requiring regular or current medical treatment and/or follow up. For the purposes of this study, an investigator may classify a medical condition as a nonsignificant disorder despite the fact that the subject receives treatment. Subjects having controlled Stage 1 hypertension (blood pressure of 140-159 mmHg systolic and/or 90-99 mmHg diastolic) are eligible for participation in this study * Normal open angle in a gonioscopic examination * Presence of glaucomatous optic disc changes in biomicroscopy and * Visual field defects in at least two visual field examinations (Reliability criteria: fixation errors \< 20%, false positives \< 15%, and false negatives \< 33%) Or * Abnormal circumpapillary retinal nerve fiber layer thinning (RNFL evaluated by OCT) Exclusion Criteria: * History of ocular or systemic disease causing optic nerve damage * History of IOP greater than 21 mm Hg (corrected by CCT) * Participation in a clinical trial in the 3 weeks preceding the study * Ocular surgery (including intravitreal injection) during the 3 months preceding the study * Ametropia \> 6 Dpt * Smoking * pre- or perimenopausal women * Relevant ophthalmic diseases/conditions that could interfere with LSFG measurements (e.g. optic nerve head drusen, tilted disc, etc.) * Opacities of the cornea (e.g. corneal scars, corneal oedema), the lens (e.g. LOCS-II grading \> 2, posterior capsule opacification) or the vitreous (e.g. vitreous haemorrhage, asteroid hyalosis) * Patients who are not able to cooperate or with insufficient ability to fixate (tremor, nystagmus) * Blood donation in the 3 weeks preceding the study * Symptoms of a clinically relevant illness in the 3 weeks before the first study day * Ocular infection or clinically significant inflammation * Pregnancy, planned pregnancy or lactating