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.
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.
ObjectiveTo observe the inhibitory effect of endostatin (ES) on oxygen-induced retinal neovascularization.MethodsThirtyfour 7-day-old C57BL/6J mice were randomly divided into 3 groups: oxygen-exposed group (12 mice), ES group (12 mice) and the control group (8 mice). The mice in oxygen-exposed and ES group were exposed to (75±5)％ oxygen for 5 days and then back to the normal air. In ES group, 1 μg ES endostatin were injected into vitreous in one eye, while PBS was injected into the other eye as the control 12 and 36 hours after being exposed to oxygen. The mice in the control group were fed in normal circumstance. The changes of retinal neovascularization was examined by fluorescence angiography with fluorescein isothiocyanatedextran. The number of endothelial cells breaking through the internal limiting membrane (ILM) was counted and the inhibitory effects of ES on retinal neovascularization was observed.ResultsCompared with the oxygen-exposed group, the branches of retinal vessels went normal without any un-perfused area in ES group. The number of nuclei of endothelial cells breaking through ILM on each retinal crosssection decreased to (5.39±1.52), which differed much from that in the oxygen-exposed group (22.56±2.13) (plt;0.001).ConclusionES can effectively inhibit the formation of retinal neovascularization in rats and might be a new path of the treatment for proliferative retinopathy.(Chin J Ocul Fundus Dis, 2005,21:314-317)
PURPOSE:To observe the clinical features of the macular hemorrhage in myopes. METHOD:Twenty-four patients(30 eyes)with myopic macular hemorrhage were examined with slitlamp biomicroscopy,funduscope,A/B ultrasonography,and fundus fluorecein angiography(FFA). The patients were followed up for 3~18 months(average 12 months). RESULTS: Four of 26 eyes with macular hemorrhage examined with FFA were found to be due to choroidal neovaseulature,and they were associated with posterior staphyloma. The other 22 eyes without neovascular change were thought to be simple type,and 19 of them were associated with lacquer cracks. The hemorrhage in simple type cases deminished usually within 1~3 months. CONCLUSION:Myopic macular hemorrhagic eyes of neovascular type resulted usually in recurrent hemorrhage and worse prognosis in visual acuity than those of simple type. （Chin J Ocul Fundus Dis,1996,12: 220-222）
Objective To investigate the characteristics and analyze the differences of choroidal neovascularization (CNV) image between exudative age-related macular degeneration (AMD) and central exudative chorioretinopathy (CEC) using optical coherence tomography (OCT). Methods Twenty-three eyes of 22 patients with exudative AMD and 20 eyes of 19 patients with CEC, which were diagnosed as CNV using fundus fluorescein angiograph (FFA) or indocyanine green angiograph ( ICGA), were examined by OCT.The size of CNV and the thickness of retinal neurosen sory layer in foveola were measured by OCT software. Results On OCT image, CNV had three main types of morphological features including simple CNV, CNV with serous retinal neurosensory layer detachment and CNV with choroidoretinal exudation. Exudative AMD mainly showed CNV with choroidoretinal exudation (56.52%) and CEC showed simple CNV (90.0%). The thickness of retinal neurosensory layer in foveola of patients with exudative AMD was thicker than that of patients with CEC and the size of CNV of patients with exudative AMD was larger than that of patients with CEC. Negative correlation was found between retinal neurosensory layer thickness in foveola and vision in both groups (gamma;=-0.521, P=0.001). Conclusions There were certain discrepancy in morphology and area in volved of CNV between exudative AMD and CEC on OCT images. (Chin J Ocul Fundus Dis, 2001,17:299-302)
Anti-vascular dndothelial growth factor (VEGF) drugs have open up a new treatment channel for ocular neovascular diseases. A lots of clinical data has proved that anti-VEGF drugs are effective and safe. But we should also notice that long-term and excessive usage of anti-VEGF drugs brings some new problems and complications, and even affect the normal ocular physiological process of the angiogenesis and retinal blood flow. So, it is necessary to pay attention to the problems and potential risks of excessive usage of anti-VEGF therapies for ocular neovascular disease.
Objective To investigate the effects of recombinant adeno-associated virus type-2 (rAAV2) mediated delivery of pigment epitheliumderived factor (PEDF) on oxygen-induced retinal neovascularization (OIRNV) in mice. Methods A total of 22 C57/BL6 mice at the age of 3 days received intravitreal injections of 1 mu;l rAAV2-PEDF and rAAV2EGFP into the left eyes (experimental group) and the right eyes (control group). All mice were put into the oxygen box right after the injection to induce the OIRNV model.4 mice were sacrificed and PEDF protein in retina was measured by western blot at postnatal days 13 (P13). Twelve mice underwent retinal angiography with high molecular weight fluoresceindextran, and another 6 mice were sacrificed for retinal lectin immunohistochemistry staining at P17. Absolute and relative nonperfusion areas of retinal neovascularization were analyzed by Image-Pro Plus 5.1 software. Results The expression level of PEDF protein was higher in the experimental group than that in the control group.The absolute nonperfusion area was (0.96plusmn;0.22) mm2 in the experimental group and (1.96plusmn;0.34) mm2 in the control group; the difference between the two groups was significant（t=-8.554, P＜0.01）. The relative nonperfusion area was (8.64plusmn;1.52)% in the experimental group and (17.27plusmn;2.98)% in the control group with a significant difference between the two groups (t=-8.97, P＜0.01).The absolute area of retinal neovascularization was (0.37plusmn;0.11) mm2 in the experimental group which was obviously higher than (1.26plusmn;0.38) mm2 in the control group (t=-7.8, P＜0.01); the relative areas in experimental and control groups was (3.96plusmn;0.66)% and (11.45plusmn;2.06)%, respectively, whose difference is apparently(t=-8.51, P＜0.01).The areas of retina neovascularization were (0.11plusmn;0.003) mm2 and (0.41plusmn;0.02) mm2 in the experimental and control groups, respectively, and the difference between the two groups was significant（t=-5.14, P＜0.01）.Conclusions PEDF protein can stably express in the mice retina after rAAV2-PEDF transfetion. rAAV2-PEDF can decrease the retinal non-perfusion areas and inhibit the retinal neovascularization in OIRNV mice.
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.
Objective To investigate the therapeutic efficacy of transpupillary thermal therapy (TTT) for age-related macular degeneration (AMD) accompanied with subfoveal choroidal neovascularization (CNV). Methods Fifty-one eyes of 47 patients whose illness had been diagnosed as AMD by fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were treated with diode 810 laser. There are 42 eyes of 39 patients had occult CNV and 9 eyes of 8 patients had classic CNV, and the average visual acuity in their fist diagnosis was 0.12. According to the focus size, the diameters of beam spot varied from 0.8, 1.2, 2.0, and 3.0 mm; and the power was 120, 160, 260 and 360mW correspondingly, with the duration of 60 seconds. The follow-up examination was performed once a month after the treatment, and repetitious treatment would be taken once to thrice if necessary. The follow-up period was 3~33 months with the mean of 10 months. Visual acuity, haemorrhage in ocular fundus, absorption of exudation, and the closure of CNV were examined in the follow-up examination. Results No immediate decrement of visual acuity or any other discomforts were found in all of the treated eyes soon after the treatment. The average visual acuity of 51 eyes was 0.16 in the last diagnosis, which remained no change in 68.62%; increased in 23.53% and decreased in 7.84% compared with that in the first diagnosis. The results of FFA and ICCG demonstrated that at the 3rd months after the treatment, the closure rate was 42.86% in occult CNV and 22.22% in classic CNV; and at the 6th month, the closure rate was 73.81% in occult CNV and 66.67% in classic CNV. The results of ophthalmoscopy showed that at the 3rd month after the treatment, partial or complete absorption of hemorrhage and/or exudates with various thickness of organized scarring tissue was found in 42 eyes with occult CNV; decrement of hemorrhage and exudates was observed in 7 out of 9 eyes with classic CNV; and new hemorrhage occurred in 1 eye. At the 6th month, in 27 eyes with occult CNV, new hemorrhage occurred in 3 including 2 eyes with occult CNV, new hemorrhage occurred in 3 including 2 eyes with faster absorption and remaining unchanged for 12 months; in 5 eyes with classic C NV, new hemorrhage occurred in 2, which was absorbed after treated again and remained stable in the 16-month followed-up. In 19 eyes with occult CNV which had been followed up for more than 6 months, hemorrhage disappeared in 5 and new hemorrhage occurred in 5. In the followed-up over 6 months, new hemorrhage occurred in 8 eyes with the recurrent rate of 15.6%. Conclusion TTT is effective for AMD with either classic or occult CNV. In the long-term followed-up, CNV recurs in 15.6% of the treated eyes which may be improved after the further treatment. (Chin J Ocul Fundus Dis，2004，20：280-284)