Purpose: That vascular endothelial growth factor (VEGF) plays a major role in inflammatory angiogenesis has been well established. This pilot study was designed to evaluate experimental treatment with bevacizumab eyedrops in corneal neovas-cularization induced by alkali burn. The feasibility of topical administration, cor-neal cell viability and corneal penetration were investigated in an animal model. Methods: Eighteen chinchilla bastard rabbit corneas injured with 1 m NaOH were divided into three groups: untreated, early and late treatment groups. Eyedrops of bevacizumab solution (25 mg ⁄ ml) were administered five times daily. Clinical examination under stereoscopic microscope was performed to evaluate corneal opacity, neovascularization, vessel size and oedema. Histopathology was analysed for vessel density and apoptotic reaction. Additionally, intracameral bevacizumab concentration was measured with enzyme-linked immunosorbent assay (ELISA) after repeated topical applications. Results: A fast increase in aqueous bevacizumab concentration was achieved when the solution was instilled every minute onto a healthy eye surface. As well as clear anti-angiogenic effects, anti-fibrotic effects were also seen after corneal burn, maintaining corneal transparency. Early treatment of actively growing vessels showed a significantly better outcome, although apoptosis of pre-existing vessels could also be induced by the late treatment. No specific toxicity was seen regarding epithelium, keratocytes or endothelium. Conclusions: The data from this pilot study suggest that bevacizumab eyedrops can sufficiently penetrate the corneal stroma and anterior chamber. When administered soon after alkali burn, bevacizumab seems to significantly reduce corneal damage. Combinations of established treatment regimens with topical bevacizumab might be considered in severe injuries with otherwise devastating prognoses.
These results demonstrate the neuroprotective effect of H-1152P-mediated ROCK-inhibition on retinal cells under stress, which may rely partly on the attenuation of glial cell reactivity.
The improved dual-immunoenrichment assay enabled the detection of intact and viable CMC in the majority of UM patients. We also were able to identify CMC after short-term culturing. Molecular characterization of the CMC rather than the prevalence of these cells is expected to provide relevant information on the individual risk of metastasis.
Monosomy-3 in primary uveal melanoma (UM) is associated with a high risk of metastasis and mortality. Although circulating melanoma cells (CMC) can be found in most UM patients, only approximately 50% of the patients develop metastases. We utilized a novel immuno-FISH assay to detect chromosome-3 in intact CMC isolated by dual immunomagnetic enrichment. Circulating melanoma cells were detected in 91% of the patients (n = 44) with primary non-metastatic UM, of which 58% were positive for monosomy-3. The monosomy-3 status of CMC corresponded to the monosomy-3 status of the primary tumor in 10 of the 11 patients where this could be tested. Monosomy-3 in the CMC was associated with an advanced tumor stage (P = 0.046) and was detected in all four patients who developed metastasis within the follow-up period of 4 yr. This non-invasive technique may enable the identification of UM patients at risk for metastasis particularly when a primary tumor specimen is unavailable.
ABSTRACT.Purpose: That vascular endothelial growth factor (VEGF) plays a major role in inflammatory angiogenesis has been well established. This pilot study was designed to evaluate experimental treatment with bevacizumab eyedrops in corneal neovascularization induced by alkali burn. The feasibility of topical administration, corneal cell viability and corneal penetration were investigated in an animal model. Methods: Eighteen chinchilla bastard rabbit corneas injured with 1 m NaOH were divided into three groups: untreated, early and late treatment groups. Eyedrops of bevacizumab solution (25 mg ⁄ ml) were administered five times daily. Clinical examination under stereoscopic microscope was performed to evaluate corneal opacity, neovascularization, vessel size and oedema. Histopathology was analysed for vessel density and apoptotic reaction. Additionally, intracameral bevacizumab concentration was measured with enzyme-linked immunosorbent assay (ELISA) after repeated topical applications. Results: A fast increase in aqueous bevacizumab concentration was achieved when the solution was instilled every minute onto a healthy eye surface. As well as clear anti-angiogenic effects, anti-fibrotic effects were also seen after corneal burn, maintaining corneal transparency. Early treatment of actively growing vessels showed a significantly better outcome, although apoptosis of pre-existing vessels could also be induced by the late treatment. No specific toxicity was seen regarding epithelium, keratocytes or endothelium. Conclusions: The data from this pilot study suggest that bevacizumab eyedrops can sufficiently penetrate the corneal stroma and anterior chamber. When administered soon after alkali burn, bevacizumab seems to significantly reduce corneal damage. Combinations of established treatment regimens with topical bevacizumab might be considered in severe injuries with otherwise devastating prognoses.
ABSTRACT.Purpose: To evaluate the effects of intravitreally introduced vascular endothelial growth factor (VEGF) inhibitors in rat eyes with healthy retinal ganglion cells (RGC) and into others with N-methyl-D-aspartate (NMDA)-induced RGC damage.Methods: Bevacizumab, ranibizumab and pegaptanib were intravitreally injected each at two different concentrations. Respective vehicles of the three substances served as controls. In a different group, additionally a rat anti-VEGF antibody was injected after NMDA treatment. Retrogradely labelled RGC were counted on retinal wholemounts 1 week or 2 months after intravitreal introduction of the VEGF inhibitors. Electron microscopy (EM) was performed on normal rat eyes 2 months after introduction of the VEGF inhibitors.Results: RGC counts in healthy rat eyes were essentially unchanged from those of the control animals after the administration of both low and high concentrations of bevacizumab, ranibizumab or pegaptanib. Compared to the other two substances, however, high doses of pegaptanib and its respective vehicle significantly decreased RGC after 1 week and led to a marked increase of mitochondrial swelling in EM. In eyes with NMDA-induced RGC damage, no changes of RGC numbers were detected after rat anti-VEGF antibody or bevacizumab, ranibizumab and pegaptanib at both tested concentrations.Conclusions: Even at higher doses, bevacizumab and ranibizumab showed no toxic effects on RGC in vivo in either untreated rats or in the NMDA-induced RGC damage model. Also a rat anti-VEGF antibody showed no adverse effects after NMDA. Anti-VEGF therapy therefore appears safe even for eyes with additional excitotoxic RGC damage. Potential harm from the pegaptanib carrier solution at very high local concentrations cannot be excluded.
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