J Korean Ophthalmol Soc.  1975 Dec;16(4):404-407.

Normal Fundus Veasels: The First and the Second Bifurcations

• Lee JH
• Sohn KT
• Cho HW

Abstract

Normal retinal vessels around the first and the second bifurcations were analysed with fundus photographs taken by Zeiss fundus camera. Horizontal disc diameter was set to 10, which was taken as standard units. 1. Distances of the first and the second bifurcations of the retinal vessels from the disc margin were variable; average distance being 10.01 +/- 4.83 (2.0~29.0) and 11.36 +/- 7.99 (1.5~40.0) for the first arterial and venous bifurcations, and 19.47 +/- 8.03 (5.0~42.0) and 22.84 +/- 10.49 (5.0~47.0) for the second arterial and venous bifurcations. 2. Arterial and venous diameters were: 0.56 +/- 0.11 (0.4~1.0) and 0.72 +/- 0.16 (0.5~1.1) at one to two disc diameters from the disc margins, and 0.53 +/- 0.09 (0.4~0.6) and 0.62 +/- 0.14 (0.4~0.9) at three to four disc diameters. 3. Ratio of venous to arterial diameters were 1.285 +/- 0.332 (0.57~2.00) at the first bifurcations and 1.137 +/- 0.266 (0.77~1.77) at the second bifurcations. The ratio was smaller at periphery than at central area. 4. Diameters of arteries became narrower more gradually than those of veins after bifurcations. After the second bifurcations, ratio of the sum of branched vascular diameters to the vascular diameters before bifurcations were 1.617 (0.9~3.0) for artery and 1.454 (0.9~2.8) for vein.

MeSH Terms

Arteries
Retinal Vessels
Veins