Objective To evaluate the inhibited effects of small interfering RNA targeting Rac1 (Rac1-siRNA) on rat retinal neovascularization in retinae. Methods Retinal vein occlusion was induced by retinal photodynamic medthod in 25 Sprague-Dawley rats. Rac1-siRNA vector DNA was injected into the vitrous of one eye of those rats (gene intervention group), and empty vector DNA was injected into the fellow eye (blank control group). Rac1-siRNA vector was injected in other 25 SD rats without retinal vein occlusion (blank intervention group). Two weeks after injection, fluorescein isothiocyanate (FITC)-dextran was perfused into the hearts of all the rats, and the retinal wholemount was made to observe the neovascularization. The numbers of endothelial cells which break through the internal limiting membrane were counted after hematoxylin-eosin staining. Results A massive of neovascularization and FITC leakage were found in blank control group. Small part of neovascularization and a little FITC leakage were observed in the gene intervention group. Retinal vessels were normal in blank intervention group. Compared with blank contrast group and blank intervention group, the difference of the mean numbers of endothelial cells which broke through the internal limiting membrane in the gene intervention group was significant（t=? P=0.000??lt;0.05）. Conclusion Rac1-siRNA can inhibit retinal neovascularization induced by retinal vein occlusion in rats.
Objective To investigate the related factors of effects on distant visual acuity after photodynamic therapy (PDT) for choroidal neovascularization (CNV). Methods One hundred and thirty-five cases (135 eyes ) of CNV treated with PDT were observed. The gender, preoperative distant and near visual acuity, disease course, pathogeny, area of CNV, types of CNV ascertained by fundus fluorescein angiography (FFA), and changes of CNV in FFA were recorded. Multi-factor regression analysis of visual acuity within 1 month and 3 months after PDT was performed with SPSS statistics software. Results The distant visual acuity within 1 month postoperatively was related to the preoperative distant visual acuity, the area of CNV and the changes in the FFA（P=0.000,0.030,0.062）, and 3 months after PDT, it was related to the distant and near visual acuity preoperatively and the changes in the FFA（P=0.000,0.054,0.034）. The condition of distant visual acuity within 1 month postoperatively was related to the FFA type of CNV and the disease course（P=0.018,0.08）. Conclusion The smaller the area of CNV is, the better postoperative distant visual acuity would be. The proportion of improvement of visual acuity is relatively higher in patients with classic CNV. Early treatment for the patients with the indicatio may improve the visual acuity effectively. (Chin J Ocul Fundus Dis，2004，20：292-294)
The therapeutic effect of anti-vascular endothelial growth factor (VEGF) for neovascular age-related macular degeneration (nAMD) was determined by a number of factors. Comprehensive thorough analysis of clinical features, imaging results and treatment response can predict the potential efficacy and possible vision recovery for the patient, and also can optimize the treatment regime to make a personalized therapy plan. Precise medicine with data from genomics, proteomics and metabolomics study will provide more objective and accurate biology basis for individual precise treatment. The future research should focus on comprehensive assessment of factors affecting the efficacy of anti-VEGF therapy, to achieve individualized precise diagnosis and treatment, to improve the therapeutic outcome of nAMD.
ObjectiveTo observe the expression of Rap1, guanosine triphosphate-Rap1 (GTP-Rap1), vascular endothelial growth factor (VEGF) and β-catenin in experimental choroidal neovascularization (CNV).MethodsForty-two brown Norwegian rats were randomly divided into a blank control group (7 rats) and a model group (35 rats). Both eyes were enrolled. The CNV model was established by holmium ion laser photocoagulation in the model group. At 3, 7, 14, 21, and 28 days after photocoagulation, fluorescein fundus angiography (FFA) and choroidal vascular smear were performed to observe the degree of fluorescein leakage and CNV area in rats; Western blot and real-time quantitative polymerase chain reaction (RT-PCR) were used to detect the expression of Rap1, GTP-Rap1, VEGF, β-catenin and mRNA in CNV.ResultsThe results of FFA examination showed that a large disc-shaped fluorescein leaked in the photo-condensation spot 14 days after photocoagulation. Laser confocal microscopy showed that compared with 7 days after photocoagulation, CNV area increased at 14, 21, 28 days after photocoagulation, and the difference were statistically significant (t=3.725, 5.532, 3.605;P＜0.05). Western blot showed that there was no significant difference in the relative expression of Rap1 protein in CNV at different time points after photocoagulation between the two groups (P=0.156). Compared with the blank control group, the relative expression of GTP-Rap1 protein was significantly decreased, the relative expression of VEGF and β-catenin protein were significantly increased in the model group (P=0.000). The results of RT-PCR showed that there was no significant difference in the relative expression of Rap1 mRNA at different time points after photocoagulation between the two groups (P=0.645), but there were significant difference in the relative expression of β-catenin mRNA (P=0.000). At 7, 14, 21 and 28 days after photocoagulation, there were significant difference in the relative expression of GTP-Rap1 and VEGF mRNA between the two groups (P=0.000).ConclusionsThe expression of GTP-Rap1 in experimental CNV is significantly lower than that in normal rats.
Objective To investigate the inhibitory effects of IBI302 on experimental choroidal neovascularization (CNV). Methods Affinity of IBI302 to vascular endothelial growth factor (VEGF) family cytokines (including VEGF-A165, VEGF-A121 and placental growth factor PlGF) and complements (C3b, C4b) was determined by enzyme-linked immunosorbent assay (ELISA). The antagonist effect of IBI302 on VEGF was measured by proliferation, migration and tube formation tests of human umbilical vein endothelial cells (HUVEC). The anti-complement activity of IBI302 was measured by hemolysis test mediated by complement classical pathway and alternative pathway. Rhesus laser-induced CNV model was divided into 5 groups including model control group, bevacizumab group, IBI302 0.25 mg group, IBI302 0.50 mg group and IBI302 1.25 mg group. Fluorescein angiography and optical coherence tomography were performed on these monkeys at 14 and 28 days after drug delivery to observe the fluorescein leakage area and retinal thickness. The aqueous VEGF concentration was measured at 29 days after drug delivery. Results IBI302 showed good affinity to VEGF-A165, VEGF-A121 and PlGF, as well as C3b and C4b. IBI302 significantly inhibited the proliferation, migration and tube formation of HUVEC induced by VEGF-A165. IBI302 inhibited the hemolysis induced by complements obviously. At 14 and 28 days after drug delivery, the area of fluorescein leakage and retinal thickness in IBI302 0.25 mg group, IBI302 0.50 mg group, IBI302 1.25 mg group were reduced. The differences of the area of fluorescein leakage and retinal thickness in three IBI302 groups were not significant (P > 0.05). At 29 days after drug delivery, the VEGF concentration in the aqueous of rhesus monkey in bevacizumab group [(38.644±6.521) pg/ml] was decreased than that in model control group [(94.203±17.360) pg/ml], the difference was significant (P < 0.05). The VEGF concentration in the aqueous of rhesus monkey in three IBI302 groups were less than 31.300 pg/ml. Conclusion IBI302 inhibited experimental CNV through blocking the activity of VEGF and complement.
Objective To compare the characteristics of the results of fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) in patients with classic choroidal neovasculazation (CNV). Methods The data of FFA and ICGA of 34 patients (36 eyes) with classic CNV were analyzed retrospectively and the results of the two examinations were analyzed contrastively. Results The results of FFA revealed the clew or cartheel-tike configuration of classic CNV at the early phase in 3 out of 15 eyes (20%) with age-related macular degeneration (AMD); in 5 out of 7 eyes with pathological myopia(71.4%); and in 9 out of 14 eyes with central exudative chorioretinopathy (CEC),(64.3%),In 36 eyes with classic CNV, the images of ICGA indicated CNV distinctly in 20 (55.6%) and indistinctly in 15 (41.6%); CNV was not detected by ICGA in 1 eye (2.8%); feeding blood vessels in 6 eyes (16.7%) were detected by ICGA but none by FFA. Conclusions At the early phase of FFA, the configuration of classic CNV is clew-like in eyes with pathological myopia and CEC, and erose in eyes with AMD. The image of ICGA which indicated the outline of classic CNV is not as clear as the one of FFA, but it can reveal the feeding vessels which FFA can not. (Chin J Ocul Fundus Dis, 2006, 22: 217-209)
Myopic choroidal neovascularization (MCNV) is one of the main reasons of vision loss in working population in Asia, which has brought economical and social-psychological burdens with high incidence in China, The precise pathogenesis of MCNV is unclear. Metamorphosia is the main reported symptom in these patients. The lesions were usually with smaller area, less leakage and relatively slow progression. Currently, intravitreal anti-vascular endothelial growth factor agents are now the established standard of care for MCNV, which was a major breakthrough in the treatment of MCNV achieving visual acuity improvement. Since the natural history, clinical features and therapy response of this disease is significant different from that in choroidal neovascularization secondary to age-related macular degeneration, the treatment dosing, frequency, retreatment criteria and the follow-up interval should been considerately. Facing the myopia boom in China, there is a need for the development of a precise definition and a more detailed classification for pathogenic myopia, optimize the outcome assessment and follow-up strategy, which should benefit to the further basically and clinical studies.
ObjectiveTo investigate the effects of transforming growth factor-β (TGF-β) in choroidal neovascularization (CNV) induced by laser in mice. Methods Eighty male C57BL/6J mice at the age of 6-8 weeks old were randomly divided into the normal control, photocoagulation model, photocoagulation with phosphate buffered saline (PBS control group) and photocoagulation with TGF-β receptor inhibitor groups (TGF-β receptor inhibitor group), twenty mice of each group. Fundus argon laser photocoagulation was performed in the photocoagulation model group, PBS control group and TGF-β receptor inhibitor group to induce CNV. One week, two, three and four weeks after the laser procedure, fundus fluorescein angiography (FFA) was carried out in the normal control or photocoagulation model groups to observe CNV formation dynamically. Western blot was used to analyze the expressions of TGF-β in the retina from the mice of normal control or photocoagulation model groups, and VEGF or TNF-α in the retina of normal control, PBS control or TGF-β receptor inhibitor groups. The CNV areas of each group were evaluated by using fluorescein stain on retinal pigment epithelium (RPE)/choroid flat mounts after two weeks of photocoagulation. ResultsThe FFA results showed the retinal vessels centered on the optic disc and arranged radially, while the choroidal vascular present network distribution in the normal control mice. Significant leakage of fluorescein showed discoid strong fluorophore in photocoagulation sites of retina at one week after photocoagulation. The quantitative analysis results of Western blot demonstrated that the TGF-β protein expression levels in retina of photocoagulation model mice gradually increased with time passing. The protein expression levels of TGF-β were significant differences in the photocoagulation model group comparing with the normal control group (F=13.042, P < 0.05). The protein expression levels of TNF-α (F=14.721, 17.509) and VEGF (F=18.890, 11.251) increased significantly in retina of PBS control or TGF-β receptor inhibitor groups when compared with that of normal control group at one week, two, three and four weeks after photocoagulation, and the differences were both statistically significant (P < 0.05). Compared with PBS control group, the protein levels of TNF-α and VEGF in retina from TGF-β receptor inhibitor group were significantly reduced, the differences was statistically significant (F=21.321, 16.160, P < 0.05). Two weeks after laser photocoagulation, a distinct reduction in CNV lesion size in the TGF-β receptor inhibitor group mice when compared to PBS or normal control groups, the differences was statically significant (F=4.482, P < 0.05). ConclusionTGF-β may promote CNV formation by up-regulating both TNF-α and VEGF protein expressions, the application of its specific inhibitor is able to reduce CNV progression.
ObjectiveTo assess the efficacy and safety of intravitreal aflibercept injection (IAI) compared with photodynamic therapy (PDT) in the treatment of Chinese patients with predominantly classic subfoveal choroidal neovascularization (CNV) lesions secondary to neovascular age-related macular degeneration (nAMD).MethodsA randomized, double-blind, multi-center phase-3 clinical trial lasting for 52 weeks (from December 2011 to August 2014). Subjects were randomized in a 3:1 ratio to either IAI group or PDT-to-IAI group. Subjects in the IAI group received 2 mg IAI at baseline and at week 4, 8, 16, 24, 32, 40, 48, with sham injection at week 28, 36. Subjects in the PDT-to-IAI group were forced to receive PDT once at baseline and more time at week 12, 24 if PDT retreatment conditions were met. Sham injections were given in PDT-to-IAI group at baseline and at week 4, 8, 16 and 24, followed by 2 mg IAI at week 28, 32, 36, 40, 48. The primary outcome of efficacy were the change in mean Best Corrected Visual Acuity (BCVA) from baseline to week 28, and that of week 52. Safety evaluation included the percentage of subjects who suffered treatment emergent adverse events (TEAEs).ResultsAmong the 304 subjects enrolled, there were 228 and 76 cases in IAI group and PDT-to-IAI group respectively. At week 28, the changes of mean BCVA in IAI group, PDT-to-IAI group compared to baseline were +14.0, +3.9 letters, respectively. At week 52, the changes of mean BCVA in two groups were +15.2, +8.9 letters respectively with the difference of +6.2 letters (95%CI 2.6−9.9, P=0.000 9). At week 52, the mean foveal retinal thickness in the two groups decreased by −189.6, −170.0 μm, respectively. Subjects with the most BCVA increase in IAI group were those aged ＜65, and those with active CNV lesion area ＜50% of total lesion area. The most common TEAEs in IAI group and PDT-to-IAI group are macular fibrosis [11.8% (27/228), 6.6% (5/76)] and BCVA decline [6.6% (15/228), 21.1% (16/76)]. There were 3 cases of arterial thromboembolic events defined in the antiplatelet experimental collaboration group, but all were considered unrelated to interventions.ConclusionsThe efficacy of aflibercept is superior to that of PDT in nAMD patients in China. The therapeutic effect of aflibercept persisted to week 52 in all subjects. The rate of adverse events was consistent with the safety data of aflibercept known before.
ObjectiveTo observe the effects of angiostatin on the activity of extra-cellular signal-regulated protein kinase (ERK) of retinal microvascular endothelial cells of mice.MethodsAngiostatin was separated and purified by l-lysine sepharose 4B from human plasma. The primary retinal microvascular endothelial cells were divided into 4 groups: the control group, vascular endothelial growth factor (VEGF) 10 ng/ml group, angiostatin 130 μg/ml group, and VEGF (10 ng/ml) + angiostatin (130 μg/ml) group. The expression of ERK1 was assayed by Westernblotting method 1, 2, 5, 10, 15, and 30 minutes after the treatment of angiostatin.ResultsCompared with the control group, the expression of ERK-1 reduced 1 minute after treatment, reduced markedly after 10 minutes. After 30 minutes, no differences of the expression of ERK were seen between the control group and angiostatin group. The activation of ERK-1 of retinal microvascular endothelial cells occurred after stimulated by VEGF, and at the pitch at the peak after 5 minutes. The level of ERK in VEGF group increased 210% than that in the control (P＜0.05). After 30 minutes, no significant difference of the level of ERK between VEGF and the control group. And because of angiostatin, the expression of ERK-1 decreased 11.9%(1 minute)、17.9%(2 minutes)、38.7%(5 minutes)、49.3%(10 minutes) （P＜0.05）、27.9%(15 minutes)、1.12%(30 minutes) respectively.ConclusionsAngiostatin can effectively block the signal path through which VEGF transmits from outside of the cell to cellular nuclei. (Chin J Ocul Fundus Dis, 2005,21:170-173)