Effect of intravitreal bevacizumab on iris vessels in neovascular glaucoma patients.
BACKGROUND
We aimed to investigate the effects of a single 1-mg injection of intravitreal bevacizumab on iris vessels in neovascular glaucoma (NVG) patients.


METHODS
Twenty-two surgically resected irises from glaucoma patients were obtained during trabeculectomy. Eight were from patients with NVG who received a 1-mg injection of intravitreal bevacizumab (IVB) before glaucoma surgery, eight were from patients with primary open-angle glaucoma (POAG), and six were from patients with NVG who were not administered IVB. The collected iris specimens were compared after immunohistochemical staining with anti-CD34 monoclonal antibodies and anti-VEGF monoclonal antibody, and the percentage of CD34-positive and VEGF-positive regions in the total area of the specimens from the three groups was compared.


RESULTS
The difference in the CD34-positive area between all groups was statistically significant (p = 0.0061, Kruskal-Wallis test). There was no significant difference in the CD34-positive area between the NVG with IVB group and the POAG group (p = 0.3017, Mann-Whitney U test with Bonferroni correction). The POAG group had significantly fewer CD34-positive regions than the NVG without IVB group (p = 0.0019, Mann-Whitney U test with Bonferroni correction). Many vessels remained in the iris stroma, and there was no significant difference in the CD34-positive area between the NVG with IVB and NVG without IVB groups (p = 0.0357, Mann-Whitney U test with Bonferroni correction). The ratio of the length of CD34 expression on the iris surface in the NVG without IVB group was significantly longer than that in the NVG with IVB group (p = 0.0002, Mann-Whitney U test). The difference in VEGF expression between all groups was statistically significant (p = 0.04, Kruskal-Wallis test). There was no significant difference between the NVG with IVB group and the NVG without IVB group (p = 0.7963 Mann-Whitney U test with Bonferroni correction). The frequency of hyphema and fibrin formation in the anterior chamber 1 day after surgery between the two NVG groups was not statistically significant.


CONCLUSIONS
A single intravitreal dose of IVB at 1 mg/0.04 ml to eyes with rubeotic glaucoma reduced the neovascularization in the human iris surface, but could not eliminate completely neovascularization in iris stroma. This finding implies that the prevention of hyphema and fibrin formation based on the slit-lamp examination can not be predicted, even if neovascularization in iris surface seems to be eliminated by a single dose of IVB.
Sugimoto
Yosuke
Y
Department of Ophthalmology and Visual Science, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan. sugimoto@hiroshima-u.ac.jp
Mochizuki
Hideki
H
Okumichi
Hideaki
H
Takumida
Masaya
M
Takamatsu
Michiya
M
Kawamata
Seiichi
S
Kiuchi
Yoshiaki
Y
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage*; D000911:Antibodies, Monoclonal / Q000008:administration & dosage*; D061067:Antibodies, Monoclonal, Humanized; D018952:Antigens, CD34 / Q000378:metabolism; D000068258:Bevacizumab; D005260:Female; D015355:Glaucoma, Neovascular / Q000188:drug therapy* / Q000378:metabolism; D005902:Glaucoma, Open-Angle / Q000188:drug therapy / Q000378:metabolism; D006801:Humans; D058449:Intravitreal Injections; D007498:Iris / Q000098:blood supply*; D008297:Male; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000188:drug therapy*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D018952:Antigens, CD34; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab