REtinal Markers In Neuroinflammatory Diseases ("REMIND")

OCT is used to measure: * peripapillary retinal nerve fiber layer (mean thickness in μm) * ganglion cell-inner plexiform layer (volume in mm\^3 and mean thickness in μm) * other retinal layers (inner nuclear layer, outer plexiform layer, outer nerve layer; volumes in mm\^3 and mean thickness in μm). The "scanner laser ophthalmoscopy"-function of the OCT device is used to continuously record the exact location of each participant's fixation point in relation to their fovea and thereby allows the assessment of the fixation instability. In a subgroup of participants, the "angiography"-module of the OCT device is used to image the retinal blood flow and thereby allows to measure the vascular area density of the superficial retinal capillary plexus and deep retinal capillary plexus.

Static retinal vessel analyzer is used to determine: * central retinal arteriolar diameter equivalents (in μm) * central retinal venular diameter equivalents (in μm) * arteriolar-to-venular diameter ratio

In a subgroup of participants, the dynamic retinal vessel analyzer is used to determine the arteriolar ficker light-induced dilatation, venular ficker light-induced dilatation, and Arteriolar constriction, measured in % dilatation in comparison to baseline.

In a subgroup of participants, the laser speckle flowgraphy system is used to measure the relative ocular blood flow as expressed in arbitary units of Mean Blur Rate.

All study participants will be asked to fill in a questionnaire with various questions regarding existing eye diseases, other diseases (including vascular diseases/risk factors), and daily physical activity that could influence the results of the retinal examinations. Physical activity will be assessed using an adapted form of the standardized Global Physical Activity Questionnaire.