which are larger: retinal arteries or veins?

[GingerSue]

The A:V ratio comparing the retinal artery-to-vein width is 2:3 or 4:5

does this mean that the arteries are larger than the veins?

[TakeTwoAspirin, MSN, RN, APRN]

Arterioles are smaller than venules, generally by a ratio of 3:5 to 2:3.

If you do the math:

3/5 = .6

2/3 = .67

So, arterioles are just over half as small venules.

Hope this helps.

[RNMeg]

Having worked in an optometry office, I've seen a lot of retinas..the doctors always told me that the arteries are larger than the veins, especially in hypertensive patients (the artery gets about twice as large as the vein). Hope that helps!

[GingerSue]

if I look and see some vessels larger than others - how will I know whether they are

arteries or veins? (colour is one way - the arteries have thin sliver of light reflex)

[TakeTwoAspirin, MSN, RN, APRN]

The arterioles should look "brighter" in color and slightly smaller than the venules (although size may be more difficult to distinguish in "normal" eyes), because the light reflects back off oxygenated blood differently. The brightness of the red in the arterioles may be a better benchmark for you than the size.

[carol72]

If you are interested in seeing photos of retinal veins and arteries, check out www.eyecancer.com There is quite a difference, this is most obvious on IVFA images. I hope he still has them available.

[MB37]

We've already been tested on this once this semester. My class notes state:retinal arteries are brighter red and smaller in size than veins. The artery:vein ratio is 2:3 or 4:5 according to my textbook, and regardless of the exact number, arteries are smaller.

[allthingsbright]

Ok, I may not know what I am talking about here, but wouldnt arteries be biiger in veins in that they take blood away from the heart and function under more pressure due to the increased amount of cardiac output? Just wondering about the rational behind it all because I have nothing else to do (HA!).