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 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.
ObjectiveTo study the inhibitory effects of pigment epithelium derived factor (PEDF) on oxygen-induced retinal neovascularization in mice, and to investigate the possible involvement of interleukin-1β (IL-1β) in the neovascular-inhibitory function of PEDF. Methods A total of 140 postnatal day (P)7 C57BL/6 mice were randomly divided into normal control group, oxygen-induced retinopathy (OIR) model group, PEDF treatment group and PBS treatment control group. All mice except normal control group with their mothers were exposed to (75±2)% oxygen environment for 5 days and then kept in room air for another 5 days to establish the OIR model. Mice in normal control group were kept in room air only. At P12 and P14, respectively, mice in PEDF treatment group received intravitreous injections of 1 μl PEDF (2 μg/μl), while PBS treatment control group received the same volume of PBS (10 mmol/L, pH7.4).All mice were euthanized at P17 and eyes were isolated. The changes of retinal vessels were observed on retinal flat mounts and cryosections by fluorescence microscopy. Retinal specimens were prepared for IL-1β protein and mRNA analysis by Western blot and real time fluorescence quantitative reverse transcription-polymerase chain reaction (Real-time RT-PCR). ResultsChanges of retinal vessels had been viewed by fluorescence microscopy on flat-mounted retina, the relative retinal neovascularization areas were significantly increased in OIR model group compared with normal control group (t=15.02, P < 0.01), and the relative retinal neovascularization areas were obviously smaller in PEDF treatment group than those in PBS treatment control group (t=5.96, P < 0.01). Fluorescence staining revealed that retinal vascular tufts were extending from outer plexiform layer (OPL) to ganglion cell layer (GCL) of the retina along with multiple interconnections; Neovascular tufts in OIR model group and PBS treatment control group were presenting distinctly more than those of normal control group and PEDF treatment group. The specific expression levels of IL-1β protein in retinas of OIR mice by Western-blot analysis were higher than those of normal control group(t=3.35, P < 0.05), While these of PEDF treatment group showed a considerable decline in comparison with PBS treatment control group (P < 0.01), and there were no difference in normal control group and PEDF-treated group (F=11.764, P > 0.05). Similarly, expression levels of IL-1β mRNA tested by Real-time RT-PCR were obviously increased in the OIR model group when compared to normal control group(t=4.43, P < 0.01). After treated with PEDF, expression levels of IL-1β mRNA showed a considerable decrease when compared to PBS treatment control group (P < 0.01), and there were no difference in normal control group and PEDF-treated group (F=11.15, P > 0.05). ConclusionsPEDF can inhibit oxygen-induced retinal neovascularization. The mechanism may be related to that PEDF can downregulate the expression of IL-1β in retina.
ObjectiveTo evaluate the inhibitory effect of small interfering RNA (siRNA) targeting peroxisome-proliferator-activated receptor-γcoactivator-1α(PGC-1α) on retinal neovascularization in the mouse. MethodsEighty seven-day-old C57BL/6J mice were divided into normal group, model blank group, model control group and PGC-1αsiRNA group, twenty mice in each group. Mice in the normal group were kept in normal room air. Mice in the model blank group, model control group and PGC-1αsiRNA group were induced for retinal neovascularization by hypoxia. Liposome with PGC-1αsiRNA (1 μl) and liposome with negative control siRNA (1 μl) were injected into the vitreous in the PGC-1αsiRNA group and model control group respectively when mice were moved out to room air from the cabin (Postnatal 12). No injection were performed in the model blank group. At postnatal 17, fluorescein angiography was used to assess the vascular pattern.The proliferative neovascular response was quantified by counting the nuclei of new vessels extending from the retina into the vitreous in cross-sections. PGC-1αand vascular endothelial growth factor (VEGF) level in retina were measured by real-time polymerase chain reaction (real-time PCR) and Western blot. Inhibition efficiency of PGC-1αsiRNA on PGC-1αand VEGF was calculated. ResultsMice in the normal group showed reticular distribution of retinal blood vessels. Central nonperfused retina, neovascular tufts and fluorescein leakage were seen in the model blank group and model control group. Neovascular tuft and fluorescein leakage were decreased in the PGC-1αsiRNA group compared to the model blank group and model control group. The neovascular nuclei were increased in the model blank group and model control group compared to the normal group (P < 0.05). The neovascular nuclei were decreased in the PGC-1αsiRNA group compared to the model blank group and model control group (P < 0.05). The expression of PGC-1αmRNA and protein in retina was increased significantly in the model blank group and model control group as compared with normal group, while decreased 54% and 53% respectively in the PGC-1αsiRNA group as compared with model blank group and model control group (P < 0.05). The expression of VEGF mRNA and protein in retina was increased significantly in the model blank group and model control group as compared with normal group, while decreased significantly in the PGC-1αsiRNA group (decreased 48% and 40% respectively) as compared with model blank group and model control group (P < 0.05). ConclusionsIntravitreal injection of PGC-1αsiRNA mediated by liposome can inhibit retinal neovascularization in the mouse effectively.