My interest in the application of vascular micrometry to the clinical differentiation of diffuse vascular disease with hypertension was aroused by the work of Lobeck1 in 1937. In his paper he stated that the caliber of the retinal vessels in cases of red and of pale hypertension (Volhard's2 classification) differed definitely from that of normal persons. Kühn,3 as did Badtke4 in the same year, confirmed his findings for normal persons. Badtke also examined several groups of hypertensive patients, his results supporting in the main those of Lobeck. Lo Cascio5 in 1926 and Neame6 in 1936, in offering measuring procedures of their own, already had suggested that it might be possible to depend on retinal vascular measurements in the clinical grouping of patients with pathologic elevation of the systemic blood pressure.
Intraocular micrometry began with Zander7 in 1864 ; thereafter many workers offered numerous methods
KOCH FLP. RETINA IN SYSTEMIC VASCULAR HYPERTENSIONA CLINICAL STUDY OF THE CALIBER OF THE RETINAL ARTERIOLES AND THE RETINAL ARTERIAL DIASTOLIC BLOOD PRESSURE. Arch Ophthalmol. 1941;26(4):565–584. doi:10.1001/archopht.1941.00870160039003