1984 Volume 3 Pages 23-26
The changes with advancing age on retinal blood vessels of ocular fundus were investigated in six steers. The calves of Holstein-Friesian (body weight: 48.2 ± 0.75 kg) were introduced to the Cattle-breeding Center of National Federation of Kaitaku Agricultural Cooperative Associations in Tochigi Prefecture and reared there. Photographs of the fundus were taken at 6th to 277th day after the initial day of introduction with an ophthalmoscope camera (Kowa RC-II) by using of color films (Kodak Ektachrome ASA 200) under the non-anesthetic condition. The results were as follows: The rate of diameter of the superior vein to the long distance of optic disc in both eyes showed a gradual decreasing with advancing age at the points of 1.0, 1.5 and 2.0 R (R=long distance of optic disc) far from center of the disc. The differences between data of 6th and 277th day were significant (p<0.05) at the points of 1.5 and 2.0 R, respectively. There were mostly constant in any stage of age on the angle-values consisted of running line of superior and nasal or temporal arteries, respectively. Little changes with advancing age on A/V ratio of nasal or temporal vessels were recognized at the points of 1.0 and 1.5 R. The persistent hyaloid artery was observed throughout the investigation.
