The effect of intravitreal bevacizumab on ocular blood flow in diabetic retinopathy and branch retinal vein occlusion as measured by laser speckle flowgraphy

Figures & data

Table 1 Comparison of characteristics and findings before and after intravitreal injection of bevacizumab in groups with branch retinal vein occlusion and diabetic retinopathy

Group	BRVOME	DME	P-value
Number of eyes	13	12
Age	71.0±9.6	63.8±9.2	0.0565a
Sex (M: F)	(4:9)	(7:2)	*0.0402b
Optic media (lens: pseudophakia)	(11:1)	(10:3)	0.3278b
BCVA (logMAR)
Pre-IVB	0.8±0.26	0.41±0.21	**0.0016a
1 week post-IVB	0.64±0.4	0.49±0.23	0.3355a
1 month post-IVB	0.64±0.33	0.45±0.29	0.1245a
IOP (mmHg)
Pre-IVB	13.6±2.4	12.8±1.5	0.2409a
1 week post-IVB	12.1±2.3	13.4±2.3	0.1818a
1 month post-IVB	12.9±2.1	12.6±2.2	0.8062a
Foveal thickness (μm)
Pre-IVB	549.8±127.7	465.7±120.1	0.0727a
1 week post-IVB	327.5±110.1	396.8±116.1	0.2108a
1 month post-IVB	270.2±67.9	408.3±148.6	**0.0036a

Notes:

a Mann-Whitney U test

b Fisher’s exact test.

* P<0.05

** P<0.01.

Abbreviations: BCVA, best-corrected visual acuity; BRVOME, branch retinal vein occlusion-associated macular edema; DME, diabetic macular edema; IOP, intraocular pressure; IVB, intravitreal bevacizumab; logMAR, logarithm of the minimum angle resolution; M, male; F, female.

Figure 1 Best-corrected visual acuity before and after intravitreal injection of bevacizumab.

Notes: BCVA did not change significantly after 1 week or 1 month in the DME group (P=0.34) but did in the BRVOME group (P=0.049), with the most significant improvement being 1 week after IVB (P=0.03); Freidman test compared between three points pre-IVB, 1 week post-IVB, 1 month post-IVB; ^†P<0.05, scheffe’s paired comparison compares between groups, *P<0.05.
Abbreviations: BCVA, best-corrected visual acuity; BRVOME, branch retinal vein occlusion-associated macular edema; DME, diabetic macular edema; IVB, intravitreal bevacizumab; logMAR, logarithm of the minimum angle resolution.

Figure 2 Foveal thickness before and after intravitreal injection of bevacizumab.

Notes: FT did not change significantly 1 week or 1 month after IVB in the DME group (P=0.20), but did in the BRVOME group (P<0.001). FT improved in patients with BRVOME both 1 week and 1 month after IVB (P=0.007 and P<0.001, respectively); Friedman test compared between three points pre-IVB, 1 week post-IVB, 1 month post-IVB; ^††P<0.01; Scheffe’s paired comparison compared between groups, **P<0.01.
Abbreviations: BRVOME, branch retinal vein occlusion-associated macular edema; DME, diabetic macular edema; FT, foveal thickness; IVB, intravitreal bevacizumab.

Figure 3 Mean blur rate in the retinal artery, retinal vein, optic nerve head, and choroid before and after intravitreal injection of bevacizumab.

Notes: In patients with DME, a comparison of MBR values before, 1 week after, and 1 month after IVB revealed significant changes in all measured regions (retinal artery, P=0.02; retinal vein, P=0.04; ONH, P<0.001; and choroid, P=0.04). MBR after 1 week fell significantly in the retinal artery by 10.6% (P=0.03) and in the ONH by 7.27% (P=0.049). MBR after 1 week also fell by 14.8% (P=0.19) in the retinal vein and by 6.97% (P=0.15) in the choroid, but these differences were not significant. MBR after 1 month fell significantly in the retinal vein by 17.3% (P=0.049) and in the ONH by 17.1% (P<0.001). MBR after 1 month also fell by 14.7% in the retinal artery (P=0.08) and 16.7% in the choroid (P=0.06), but these differences were not significant In patients with BRVOME, a comparison of MBR values before, 1 week after, and 1 month after IVB revealed a significant change only in the choroid (P=0.04). Significant changes in MBR were not observed in the retinal artery (P=0.09), retinal vein (P=0.33), or the ONH (P=0.50). Significant changes in blood flow were not found after 1 week in any of the measured regions (retinal artery, P=0.39; retinal vein, P=0.84; ONH, P=0.50; and choroid, P=0.09). Furthermore, significant changes were not found in blood flow after 1 month in any of the measured regions (retinal artery, P=0.10; retinal vein, P=0.67; ONH, P=0.84; and choroid, P=0.07). Finally, significant changes were not found when comparing blood flow 1 week and 1 month after IVB in any of the regions (retinal artery, P=0.73; retinal vein, P=0.33; ONH, P=0.84; and choroid, P=1.00); Friedman test compared between points pre-IVB, 1 week post-IVB, 1 month post-IVB; ^†P<0.05, ^††P<0.01; Scheffe’s paired comparison compares between groups, *P<0.05, **P<0.01.
Abbreviations: BRVOME, branch retinal vein occlusion-associated macular edema; DME, diabetic macular edema; IVB, intravitreal bevacizumab; MBR, mean blur rate; ONH, optic nerve head.

Figure 4 Relationship between foveal thickness and mean blur rate in eyes with diabetic macular edema.

Notes: Pre-IVB MBR was not correlated with pre-IVB FT (P=0.33) (A). However, post-IVB MBR was correlated with post-IVB FT (R= −0.80, P=0.01) (B). Furthermore, pre-IVB MBR was correlated with post-IVB FT (R= −0.71, P=0.002) (C). One MBR sample is represented by one pixel.
Abbreviations: FT, foveal thickness; IVB, intravitreal bevacizumab; MBR, mean blur rate.

Figure 5 Relationship between foveal thickness and mean blur rate in eyes with branch retinal vein occlusion-associated macular edema.

Notes: Pre-IVB MBR was not correlated with pre-IVB FT (P=0.77) (A), nor was post-IVB MBR correlated with post-IVB FT (P=0.13) (B). In addition, pre-IVB MBR was not correlated with post-IVB FT (P=0.32) (C). One MBR sample is represented by one pixel.
Abbreviations: FT, foveal thickness; IVB, intravitreal bevacizumab; MBR, mean blur rate.

Figure 6 Representative eye with diabetic macular edema.

Notes: Images from a 59-year-old man with DME in his right eye; Fundus color photographs (A and D), color LSFG maps (B and E), and axial OCT images at fovea (C and F) are shown. Pre-IVB findings are above (A, B, and C) and findings 1 month after IVB are below (D, E, and F). In the color LSFG maps (B and E), the numbers 1 and 2 indicate the rectangular scanning areas for the retinal artery and vein, respectively; 3 and 4 indicate the circular and square scanning areas for the optic nerve head and choroid, respectively. Pre-IVB MBR was 30.1 in the retinal artery, 43.6 in the retinal vein, 31.0 in the optic nerve head, and 7.0 in the choroid. MBR 1 month after IVB was 22.6 (24.9% decrease) in the retinal artery, 30.3 (30.5% decrease) in the retinal vein, 24.2 (21.9% decrease) in the optic nerve head, and 5.8 (17.1% decrease) in the choroid. Decimal best-corrected visual acuity in the right eye was 0.3 before IVB and did not change 1 month after IVB. FT in the right eye was 425 μm before IVB and 272 μm 1 month after IVB.
Abbreviations: DME, diabetic macular edema; FT, foveal thickness; IVB, intravitreal bevacizumab; LSFG, laser speckle flowgraphy; MBR, mean blur rate; OCT, optical coherence tomography.

Figure 7 Representative eye with branch retinal vein occlusion-associated macular edema.

Notes: Images from a 65-year-old woman with BRVOME in her left eye. Fundus color photographs (A and D), color LSFG maps (B and E), and axial OCT images at fovea (C and F) are shown. Pre-IVB findings are above (A, B, and C) and findings 1 month after IVB are below (D, E, and F). In the color LSFG maps (B and E), the numbers 1 and 2 indicate the rectangular scanning areas for the retinal artery and vein, respectively; 3 and 4 indicate the circular and square scanning areas for the optic nerve head and choroid, respectively. Pre-IVB MBR was 15.9 in the retinal artery, 35.7 in the retinal vein, 23.5 in the optic nerve head, and 7.2 in the choroid. MBR 1 month after IVB was 14.0 (12.0% decrease) in the retinal artery, 33.4 (6.4% decrease) in the retinal vein, 26.0 (10.6% increase) in the optic nerve head, and 6.2 (13.9% decrease) in the choroid. Decimal best-corrected visual acuity in the right eye was 0.5 before IVB and did not change after 1 month. FT in the right eye was 364 μm before IVB and 264 μm 1 month after IVB.
Abbreviations: BRVOME, branch retinal vein occlusion-associated macular edema; FT, foveal thickness; IVB, intravitreal bevacizumab; LSFG, laser speckle flowgraphy; MBR, mean blur rate; OCT, optical coherence tomography.