Objective To observe the inhibitory effects of construction of complement factor (CFB)small interference RNA (siRNA) on choroidal neovascularization（CNV）induced by photocoagulation in rats.Methods We constructed an expression vector of CFBsiRNA by cutting CFBsiRNA and plasmid pRNATU61/Neo. Experimental CNV was induced by photocoagulation in 42 Brown Norway rats. After the model was set up, the rats were randomly divided into tail intravenous injection, vitreous injection, subretinal injection, and control group; each group except the control one had a corresponding blank plasmid control group. CFBsiRNA was injected 1, 3, and 5 days respectively after photocoagulation in the injection groups; the dosage was 50, 20, and 10 mu;g in tail intravenous injection, vitreous injection, and subretinal injection group respectively, while no injection was give to the control group after photocoagulation. Before and 14 days after photocoagulation, fundus fluorescein angiograoph (FFA) was performed and CNV development was judged by the leakage; the expression of vascular endothelial growth factor (VEGF) and factor Ⅷ were detected by immunohistochemistry. Results The leakage of fluorescein was obvious lower in tail intravenous injection group than that in the control group (chi;2=15.1620,Plt;0.05). The expression of VEGF and factor VIII in tail intravenous injection group at different time points after photocoagulation didnprime;tdiffer much (F=20.35,18.33; Pgt;0.05); while was apparently lower than that in the other groups at different time points (F=77.96,55.68; Plt;0.05).All of the groups, except tail intravenous injection group, had higher expression of VEGF and factor VIII 14 days after photocoagulation compared with that 7 days after photocoagulation (F=60.89, 61.12; Plt;0.05).Conclusions Constructed CFBsiRNA can inhibite CNV by downregulating the expression of VEGF and factor Ⅷ.
Pathological myopia can induce choroidal neovascularization (PM-CNV). The potential risk factors include ageing, long axial length of the eyeball, thinning of subfoveal choroidal thickness, fundus atrophy spot and lacquer crack. These factors may induce atrophy of retinal pigment epithelial cells (RPE) and hypoxia, resulting in vascular endothelial growth factors (VEGF) secretion by outer retina. The lesion type, location and activity of PM-CNV can be determined by fundus fluorescein angiography. The features of PM-CNV on optical coherence tomography include strong reflective area close to RPE with very small amount of subretinal fluid (active stage), surface strong reflection with signal attenuation area (scar stage) and flat lesion and chorioretinal atrophy (atrophy stage). Photodynamic therapy and intravitreal injection of anti-VEGF drugs are major treatments for PM-CNV, the latter is more commonly used now. However, more large randomized controlled studies are required to explore the treatment regimen (such as frequency, indications for repeated or termination of treatment) and the efficacy factors further.
Objective To evaluate short-term effects of a single photodynamic therapy (PDT) treatment with visudyne (CIBA Vision Corp.) for choroidal neovascularization (CNV) in age-ralated macular degeneration (AMD). Methods Thirty cases (35 eyes) diagnosed as AMD patients with classic CNV were treated with PDT. The data of visual acuity testing, fluorescein angiography (FFA), indocyanine green angiography (ICGA) and optic coherence tomography （OCT) were used to evaluate the effects of a single treatment of PDT before and 1 week, 1 ,3 month after treatment. Results The visual acuity of 34 eyes were stable or improved in 3 months follow-up；and the visual acuity of 1 eye was decreased. Decrease or dispearance of fluorescein leakage from CNV was noted in 19 eyes. No serious complication occurred. Conclusion Single treatment of PDT for CNV in AMD can achieve short-term decrease or cessation of fluorescein leakage from CNV without loss of visual acuity. (Chin J Ocul Fundus Dis, 2002, 18: 171-174)
Objective To summarize the therapeutic effect and clinical characteristics of repetitive photodynamic therapy (PDT) for patients with exudative age-related macular degeneration (AMD). Methods The clinical data from 78 patients (94 eyes) with exudative AMD who had undergone PDT from July, 2002 to March, 2005 were retrospectively analyzed. The average age of the patients was 68.4, and the treated times was 132 (mean 1.4). Thirty eyes underwent PDT 68 times, including twice in 22 eyes (73.3%), 3 times in 7 eyes (23.3%), and 6 times in 1 eye (3.3%). The follow-up period lasted 3-32 months with the average of 16.7 months. Results In the final follow-up examination, the results of fundus fluorescein angiography or combined with indocyanine green angiography showed that the leakage of choroidal neovascularization (CNV) stopped in 14 eyes (46.7%), reduced in 12 (40%), and remained in 4 (13.3%). Compared with the condition before first PDT, the correct visual acuity increased ge;2 lines in 7 eyes (23.3%), changed plusmn;1 line in 14 eyes (43.3%), and decreased ge;2 lines in 9 eyes (30%) in the final examination. After first PDT, the best corrected visual acuity increased ge;2 lines in 13 eyes (43.3%), changed plusmn;1 line in 12 eyes (40%), and decreased ge;2 lines in 5 eyes (16.7%). During the follow-up period, the best corrected visual acuity occurred after first PDT in 24 eyes (80%), after second PDT in 5 eyes (16.7%), and after third PDT in 1 eye (3.3%). Conclusions In patients undergone repetitive PDT, CNV in most of the affected eyes completely or partly closed and the visual acuity improved or remained still in 67.8% of the patients in the final follow-up examination. The best correct visual acuity mainly happened after the first PDT, and as the times of PDT increased, the probability of the best correct visual acuity decreased. (Chin J Ocul Fundus Dis, 2006, 22: 220-223)
Objective To evaluate the effects of traspupillary thermotherapy (TTT) for the treatment of central exudative chorioretinopathy (CEC). Methods Twelve eyes of 12 patients who suffered from CEC were treated by using a diode laser at 810 nm. A variable spot size of 0.5mm-2.0mm was used depending on the size of choroidal neovascularization (CNV).The treatment was initiated in one spot for 55 to 60 seconds duration at a power range between 200-350 mW, and the treated area revealed no visible color change to a light-gray appearance. Preoperative and postoperative fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed in 10 of the 12 eyes. Results The visual acuity in all eyes was improved to different degree over a period of 3-10 months. Five or more lines improvement measured by Snellen chart in visual acuity was found after the treatment in 4 eyes, three to five lines in 5 eyes and one to two lines in 3 eyes. All eyes demonstrated decreased or vanished exudation in FFA. CNV disappeared or decreaced in 8 eyes and remained nochange in 2 eyes in ICGA. Conclusion TTT is obviously effective in treating CEC. (Chin J Ocul Fundus Dis, 2002, 18: 187-189)
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 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.