Table 1. Previous studies of vessel diameter, mean velocity and mean flow rate in first-generation retinal blood vessels radiating out of optic disk in normal mice.

Wide disparity in measured values is observed across studies. Figure 11 graphically summarizes differences across studies. Abbreviations: N_m: number of mice, N_v: number of vessels, D: Mean diameter of vessels, V_m: Mean velocity per vessel, F_m: Mean flow rate per vessel, TRBF: total retinal blood flow per mouse (calculated by summing flow from all primary arterioles/venules around optic disk), A: primary arterioles, V: primary venules, SD: standard deviation, NOD: Non-obese diabetic. Special markers: ^ Assuming 3–7 primary arterioles and venules each per mouse retina. * SD represents variation across mice and not across vessels. An average arteriolar and venular value was calculated first for each mouse. # values represent mean ± standard error of mean. Variation is across mice and not across vessels. a: Values are mean ± SD, where SD represents variation across vessels, and not mice. Value ranges mentioned in brackets. Measurements in the current study were performed on primary retinal arterioles and venules radiating out of optic disk, at locations within a ~170–300 µm radius from the center of the optic disk. a1: Estimated by multiplying the measured F_m per vessel with the number of vessels per retina. Assumed 3–7 primary arterioles and venules per retina. b: Mean velocities are not reported here as it is unclear if the velocities reported in that study represent the mean or the sum of the individual vessel velocities per retina. c: Variation in F_m per vessel represents variation (SD) across six vessels. Variation in total flow represents variation across three independent measurements. d: Numbers correspond to diameter measurements only. For velocity measurements, N_m = 5–13, N_v = 27–71.

Study	Technique	Species	Class	Nm	Nv	D (µm)	Vm (mm s–1)	Fm per vessel (µL min–1)	TRBF (µL min−1retina−1)
Current study	Adaptive optics line-scan	15–73 week old C57BL/6J mice	A	7	11	25.9 ± 4.6 a (20.1–37.7)	15.0 ± 4.0 a (9.9–23.1)	0.52 ± 0.36 a (0.22–1.55)	1.56–3.64 a1
			V	6	7	30.6 ± 8.4 a (22.8–45.8)	11.4 ± 3.0 a (8.6–17.0)	0.57 ± 0.42 a (0.24–1.30)	1.71–3.99 a1
Liu et al., 2017	Dual ring scanning Doppler vis-OCT	13 week old non-diabetic TSP1-/- mice	A	7	21–49 ^	40.1 ± 1.8 *	- b	-	1.86 ± 0.24 *
			V	7	21–49 ^	-	-	-	-
Blair et al., 2016	Slit lamp biomicroscope	24 week old C57BL/6J mice	A	10	30–70 ^	26 ± 2 *	-	-	-
			V	10	30–70 ^	29 ± 3 *	8 ± 1 *	-	1.9 ± 0.5 *
Zhi et al., 2014	En face Doppler OCT/OMAG	BTBR wild-type mice	A/V	10	30–70 ^	-	-	-	3.05 ± 0.20 #
Wright et al., 2012	Intravital microscopy	30–31 week old male C57BL/6J mice	A	9	45	57.3 ± 1.1 #	25.3 ± 1.3 #	4.02 ± 0.28 #	-
			V	9	45	62.5 ± 2.4 #	23.2 ± 1.1 #	4.83 ± 0.41 #	-
Zhi et al., 2012	En face Doppler OCT/OMAG	22 week old female BTBR mice	A	1	6	-	-	0.47 ± 0.05 c	2.82 ± 0.30 c
			V	1	6	-	-	0.55 ± 0.10 c	3.27 ± 0.28 c
Yadav and Harris, 2011	Intravital Microscopy	16 week old male C57BL/6 mice	A	12	36–84 ^	60.0 ± 1.3 #	30.2 ± 1.4 #	5.29 ± 0.34 #	-
			V	12	36–84 ^	67.6 ± 1.6 #	28.0 ± 1.2 #	6.39 ± 0.31 #	-
Wang et al., 2011	Intravital microscopy	13 week old male C57BL/6 mice	A	7	21–49 ^	56.0 ± 1.1 #	29.0 ± 0.8 #	-	-
			V	7	21–49 ^	66.4 ± 2.8 #	25.1 ± 0.7 #	-	25.08 ± 1.92 #
Wang et al., 2010	Intravital microscopy	13–14 week old male C57BL/6 mice	A	6	30–42	54.7 ± 1.0 #	20.9 ± 0.7 #	2.98 ± 0.14 #	-
			V	6	30–42	60.8 ± 2.7 #	21.0 ± 0.7 #	3.86 ± 0.36 #	-
Wright et al., 2009	Intravital microscopy	15–16 week old male C57BL/6 mice	A	7–8	28–49	59.4 ± 0.9 #	28.3 ± 1.4 #	-	26.34 ± 2.52 #
			V	7–8	28–49	69.5 ± 1.4 #	26.3 ± 1.2 #	-	31.80 ± 2.40 #
Lee and Harris, 2008	Intravital microscopy	16–30 week old female euglycemic NOD mice	A	5	9–13	61.0 ± 1.5 #	-	3.36 ± 0.18 #	-
			V	-	-	-	-	-	-
Wright and Harris, 2008	Intravital microscopy	16 week old C57BL/6 mice	A	7–9 d	41–50 d	60.4 ± 1.1 #	23.0 ± 0.5 #	-	-
			V	7–9 d	37–49 d	71.4 ± 2.9 #	-	-	-
Ninomiya and Inomata, 2006	Scanning electron microscopy (ex vivo)	16 week old male mice	A	10	80	<28	-	-	-
			V	-	-	-	-	-	-