Non- Invasive Measurement of the Absolute Hemoglobin Value in the Retinal Arteries of Anemic and Healthy Subjects Using a New Approach

To our knowledge no tool exists that allows for direct collection of hemoglobin data in the eye. In many eye diseases (especially diabetic and hypertensive retinopathy as well as in retinal vessel occlusions) retinal circulation is modified. Knowing hemoglobin concentration on the site of the pathology will give us further information about the pathogenesis of this diseases and may provide a new possibility in therapy.

The purpose of this study is to test a new non-invasive tool to measure hemoglobin in retinal arteries. Healthy volunteers from the eye clinic and pregnant otherwise healthy patients of the gynecological department of the Triemli Hospital, Zurich, as well as anemic gynecological patients that show up for a check-up are included.

Hemoglobin will be quantified by a blood draw of a cubital vein. Using a Fundus Camera (Nidek AFC-230) pictures of the fundus will be taken from each study patient. Afterwards the study investigator selects a retinal artery of interest which will be used for measuring the hemoglobin concentration. Intensity of the green channel of the camera chip is determined with the aid of the law of Lambert-Beer.

Absolute Hemoglobin concentration is calculated in relation to the vessel volume.