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 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)
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.
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.
Choroidal neovascularization is the leading causes of central vision loss in wet age-related macular degeneration (wAMD) patients. Smoking not only aggravates the incidence and severity of the choroidal neovascularization of wAMD, but also affects the clinical treatment, making the prognosis worse. Nicotine, as an important harmful substance in tobacco, is an easily addictive and highly toxic alkaloid. Animal experiments and clinical studies have confirmed that nicotine can aggravate wAMD by mediating angiogenesis through nicotinic acetylcholine receptor, bone marrow blasts, inflammation, complement system, etc. Therefore, in order to early take appropriate intervention measures to prevent and delay the development, we should actively explore the exact pathogenesis by which nicotine aggravates the choroidal neovascularization.
Objective To investigate the role of bone marrow-derived cells (BMC) plays in choroidal neovascularization (CNV).Methods Green fluorescent protein (GFP) chimeric mice were built by transplanting BMC from GFP transgenic mice to adult wild type C57BL/6J mice. Retinal laser photocoagulation was used to induce CNV in the chimeric mice (treated group) and adult wild type mice (control group). Four weeks later, choroidal flatmount was prepared to detect GFP positive BMC expression in the CNV lesions, and immunofluorescence stain was used to determine the expression of vascular endothelia growth factor (VEGF) and basic fibroblast cell growth factor (bFGF).Results Twenty-nine days after photocoagulation lots of GFPpositive BMC presented in the CNV area, which accounted approximate 16.22% of the total CNV area. Some BMC in the CNV area expressed VEGF and bFGF. Conclusions BMC may play an important role in CNV by forming new vessles and secreting angiogenic factors.
Wet age-related macular degeneration (wAMD) is caused by choroidal neovascularization (CNV), which occurs when the choroidal new capillaries reach the RPE layer and photoreceptor cell layer through the ruptured Bruch membrane, leading to neovascularization bleeding, leakage, and scarring. In view of the important role of VEGF in the development of CNV, targeted therapy with various intraocular anti-VEGF drugs is the first-line treatment for wAMD. However, the efficacy of anti-VEGF drugs in the treatment of wAMD is affected by a variety of factors, and some patients still have problems such as unresponsiveness, drug resistence, tachyphylaxis, long-term repeated injections, and severe adverse effects. It is the direction of future researches to deeply explore the physiological and pathological process of wAMD, find the cause of CNV formation, and seek better therapies.
ObjectiveTo study changes in choroidal thickness(CT) with intravitreal injections of ranibizumab treatment.
MethodsThis is a prospective, uncontrolled, open-label study. A total of 31 eyes of 31 patients diagnosed with wet age-related macular degeneration (AMD) and 33 eyes of 33 patients diagnosed with choroidal neovascularization (CNV) secondary to pathological myopia (PM) were included in the study. All affected eyes were treated with intravitreal ranibizumab 0.05 ml (10 mg/ml) and followed up monthly until 6 months. Enhanced depth imaging on Cirrus spectral-domain optical coherence tomography was used to measure the CT. The initial CT was compared with the data at 1, 3 and 6 month after treatment, and the correlation between of the decrease of CT at the 6 month and the number of injection times was analyzed.
ResultsIn AMD group, the average CT respectively decreased by (9.68±11.02), (12.58±11.04), (13.84±11.67)μm at 1, 3 and 6 month, and the differences were significant(t=4.89, 6.34, 6.60;P < 0.001). In PM group, the average CT respectively decreased by (2.06±10.92), (3.64±8.78), (3.27±7.20)μm at 1, 3 and 6 month. The difference at 1 month was not significant (t=1.08, P=0.287). While after 3 months and 6 months, the differences were significant(t=2.38, 2.61;P=0.024, 0.014). The injection times were not correlated with the CT decreases at 6 month in both groups(r=0.04, 0.30;P=0.815, 0.099).
ConclusionIntravitreal injections of ranibizumab can induce choroidal thickness reduction for wet age-related macular degeneration and choroidal neovascularization secondary to pathologic myopia.
Objective To observe the therapeutic effects of photodynamic therapy（PDT）on choroidal neovascularization（CNV）with or without cystoid macular edema（CME）in patients with wet agerelated macular degeneration（AMD）. Methods The clinical data of 54 patients (54 eyes) with wet AMD who had undergone the standard PDT，including 16 patients（21 eyes）with CME and 28 patients（33 eyes）without CME were retrospectively analyzed. The visual acuity and BFT of patients were examined by early treatment diabetic retinopathy study (ETDRS) and optical coherence tomography（OCT）before and per three months after PDT. The follow up was 3-18 months with the mean of 8.3 months.Results At the last time of follow up, in CME group，ETDRS letter score was（29.429plusmn;17.907）and the BFT was （316.429plusmn;77.161）mu;m，compared with that before the treatment, the difference were statistically significant (t=-0.389，2.246；P＝0.701，0.019). In nonCME group, ETDRS letter score was (48.121plusmn;17.911) and the BFT was (244.667plusmn;37.619) mu;m, compared with that before the treatment, the difference were statistically significant (t=-3.424，6.880；P＝0.002，0.000). There were statistical significance for the change of ETDRS letter score and BFT between the two groups (t=-2.194，2.212；P＝0.033，0.031）). Conclusions Therapeutic effect of PDT on CNV with CME was better than without CME in patients with wet AMD.
