Objective：To observe the protective effect of ginkgo bilo ba extrac t (EGb 761), a free radical scavenger, on the photoreceptor cells after lighti nduced retinal damage. Methods：Seventytwo female SpragueDa wley (SD) rats we re randomly divided into 4 groups: normal control group, lightinduced retinal da m age model group, model+physiological saline group, and model+EGb 761 group, with 18 rats in each group. All of the rats except the ones in the control group were exposed to white light at (2740plusmn;120) lx for 6 hours after the dark adap tation for 24 hours to set up the lightinduced retinal damage model. Rats in m o del + physiological saline group and model+EGb 761 group were intraperitoneall y injected daily with physiological saline and 0.35% EGb 761 (100 mg/kg), respec tively 7 days before and 14 days after the light exposure. Apoptosis of photorec eptor cells was detected 4 days after light exposure; 7 and 14 days after light exposure, histopathological examination was performed and the layer number of ou ter nuclear layers (ONL) on the superior and inferior retina was counted. Results：Four days after light exposure, the apoptosis of photorecep tor cells was fou nd on ONL in model, model+ physiological saline and model+EGb 761 group, and w as obviously less in model + EGb 761 group than in model and model+physiologic al saline group. Seven days after light exposure, the layers of ONL on the super ior retina were 3 to 4 in model and model+physiological saline group, and 7 to 8 in model+EGb 761 group; the mean of the layer number of ONL in model+EGb 761 group (6.92plusmn;0.82) was less than that in normal control group (8.40plusmn;0.95) (t=-1.416, P＜0.05), but significantly more than that in model (5.96 plusmn;1.36 ) and model+physiological saline group (5.90plusmn;1.40）（t=1.024, 1.084; P＜0.05). Fourteen days after light exposure, the layers of ONL on the superior retina were 0 to 1 in model and model+physiological saline group, and 3 to 4 i n model+EGb 761 group. The mean of the layer number of ONL in model+EGb 761 group (5.5 2plusmn;1.06) was significantly more than that in model (3.44plusmn;2.15) and model + physiological saline group (3.37plusmn;1.91) (t=2.082, 2.146, P＜0.05). Conclusion：EGb 761 can partially inhibit the apoptosis of pho toreceptor cells, thus exert protective effect on photoreceptor cells.
Objective To investigate the early effects of intervention with tanakan on retinal function in diabetic retinopathy(DR) after laser photocoagulation. Methods Prospective random controlled study was performed on 60 Patients (60 eyes) from 23 to 69 years old with DR(phase Ⅲ～Ⅳ). The multifocal electroretinograms (MERG) were tested with VERIS Ⅳ before, the 3rd day and the 7th day after photocoagulation. Results No significant differences were found in the latencies and response densities of N1,P1 and N2 between the two groups before photocoagulation. Compared with that before photocoagulation, three days after photocoagulation the latencies in tanakan group had no significant change. The response densities of N1,P1 and N2 reduced and the changes were much smaller than that in control. Three days after photocoagulation, the response densities of P1 and N2 in the central macula 5°area were much higher and the latencies of P1 and N2 were significantly shorter than that in control group. There were no significant differences in the response densities in the 7th day and the differences in the latencies between two groups still existed. Conclusion Tanakan may be effective in preventing the retina from damage of retinal photocoagulation in some degree in DR. (Chin J Ocul Fundus Dis, 2002, 18: 208-211)
Objective To investigate the effect of inducible nitric oxide synth ase (iNOS) or cyclooxygenase－2 (COX－2) on retinal neovascularization and its possible mechanism in oxygen－induced retinopathy （OIR） mouse model. Methods Retinal neovascularization was induced by oxygen with different concentration. The expression of iNOS, COX－2, matrix metalloproteinases 2 (MMP－2) and vascular end othelial growth factor (VEGF) in the retinae of experimental animals were analyzed by immunohistochemistry, realtime polymerase chain reaction and western blotting technologies. Results The inhibition of COX－2 or iNOS obviously attenuated retinal neovascularization and decreased the expression of VEGF and MMP－2. The iNOS inhibition decreased COX－2 expression, and vice versa. Conclusions COX－2 and iNOS may play a role in retinal neovascularization in OIR mouse model, which may act by regulating the expression of VEGF and MMP－2.
Objective To observe the changes of intraocular pressure (IOP) after intravitreous injection wih triamcinolone acetonide (TA) and their affected factors. Methods The clinical data of 125 patients (125eyes) who had undergone intravitreous injection with TA were retrospectively analyzed. The patients (52 males and 73 females) aged from 17 to 83 years with the average age of 56.5. There were 49 patient (39.2%) with diabetic retinopathy (DR), 56 (44.8%) with retinal vein occlusion (RVO), and 20 (16.0%) with exudative age-related macular degeneration (AMD). One day before the treatment, IOP was measured by Goldmann applanation tonometry, and the basic IOP was 7~31 mm Hg (1 mm Hg=0.133 kPa) and the average IOP was (14.69plusmn;3.72) mm Hg. The patients were divided into two groups according to the basic IOP:below 15 mm Hg group (n=64) and 15 mm Hg or above group (n=61). All of the patients underwent intravitreous injection with 4mg TA. IOP was measured 1 day, 3 days, 1 week, 2 weeks, and 1 month after the treatment in the same way, respectively, and later was measured once every 1 month. The follow-up period was 3~21 months with the mean of 5 months. The elevation of IOP would be defined as the pressure of 21mmHg or higher. The changes of IOP in patients before and after the treatment, and with different diseases and ages were analyzed. Results Thirty-six patients (28.8%) had elevation of IOP after the treatment, out of whom 97.2% had the elevation within 3 months after the injection and decreased to the basic level 7 months after the injection. In these patients, there were 11 (17.19%) in the below 15 mm Hg group and 25 (40.98%) in 15 mm Hg or above group, and the difference between the two groups was statistically significant (P＜0.01）. During the followup period, the mean maximum IOP was (20.09plusmn;7.58) mmHg, which was 5.43 mmHg higher than that before the treatment（P＜0.001）. The mean maximum IOP of 53 patients (42.4%) after the treatment was 5 mm Hg higher than that before the treatment. The mean maximum IOP during the followup period was （18.19plusmn;4.73）mmHg in DR group，（22.50plusmn;9.30）mmHg in RVO group, and（18.12plusmn;6.09）mmHg in AMD group. The occurrence of the elevation of IOP in RVO group was obviously higher than that in the other 2 groups (P＜0.01）. The result of regression analysis showed that age was correlative with the elevation of IOP after the treatment: more risks of occurrence of high IOP were found in younger patients (P=0.000). Conclusion Elevation of IOP after intravitreous injection with TA is common, which is correlative with the basic IOP, age, and pathogeny. After the intravitreous injection with TA, the elevation of IOP often occurs in patients with high basic IOP before treatment, younger age, and RVO. (Chin J Ocul Fundus Dis, 2007, 23: 115-117)
OBJECTIVE:To verify the safe dose of cephradine in intravitreal injection. METHODS:After injecting different doses of cephradine(100mu;g,200mu;g,250mu;g,300mu;g,400mu;g)into vitreous cavity of different group of rabbits the activities of the retinal enzymes (SDH,LDH )on different time (Id,3d, 7d ) were determined respectively, and the histological and ultrastructural changes of retinas were also observed simuhaneously. RESULTS:The activity of rellnal SDH and LDH was found to be decreased gradually with tbe icreasing of the dosage of intravitreal cephradine. The activities of SDH and LDH were found in the lowest level on tile 3rd and lsl day,but they recover to normal levels on tile 7th day after intravitreal in}eetion in 100mu;g,200mu;g groups,and still lower tban normal in the other groups. Histologically,retinal edema was found both in 100mu;g and 200mu;g groups,but degradation of retinal cells,and loss of cones and rods were round in the 250mu;g, 300mu;g and 400mu;g groups. CONCLUSION: The safe dose of intravitreal injection of cepbradlnc is 200mu;g. （Chin J Ocul Fundus Dis,1997,13:139-142 ）
ObjectiveTo investigate the risk factors of postoperative vitreous hemorrhage after minimal vitrectomy without endotamponade for proliferative diabetic retinopathy (PDR).MethodsFrom June 2015 to June 2017, 103 eyes of 103 patients with PDR diagnosed and underwent minimalvitrectomy in Henan Provincial People's Hospital were enrolled in the study. There were 58 males and 45 females, with the average age of 58.37±10.14 years and diabetes duration of 8.7±7.2 years. Baseline systemic parameters including sex, age, diabetes duration, hypertension, HbA1c, creatinine, whether received anticoagulants, ocular parameters including whether combined with vitreous hemorrhage, whether finished panretinal photocoagulation (PRP), whether received treatment of anti-VEGF, whether combined with iris neovascularization (NVI), lens status preoperatively, whether hypotony postoperatively and intraoperative parameters including whether disc neovascularization (NVD) bleeding, whether fibrovascular membrane (FVM) residual, laser points, whether combined with cataract phacoemulsification were identified by multivariate logistic regression analysis.ResultsTwenty-nine of 103 eyes (28.15%) developed PVH in 1 day to 6 months after surgery, with self absorption of 18 eyes and reoperation of 11 eyes. Univariate analysis showed there were significant differences in age (t=2.124, P=0.036), anti-VEGF(χ2=7.105, P=0.008), NVD bleeding (χ2=10.158, P=0.001) and FVM residual(χ2=8.445, P=0.004) between patients with and without postoperative vitreous hemorrhage. Sex (χ2=0.021, P=0.884), diabetes duration (t=0.87, P=0.386), hypertension (χ2=2.004, P=0.157), HbA1c (t=1.211, P=0.229), creatinine (t=0.851, P=0.397), preoperative oral anticoagulants (χ2=0.985, P=0.321), preoperative vitreous hemorrhage (χ2=0.369, P=0.544), PRP (χ2=1.122, P=0.727), NVI (χ2=2.635, P=0.105), lens status (χ2=0.172, P=0.679), hypotony postoperatively (χ2=1.503, P=0.220), laser points (χ2=1.391, P=0.238) and combined phacoemulsification surgery (χ2=0.458, P=0.499) were not associated with PVH. Multivariate logistic regression analysis revealed the more PVH appeared in younger (OR=1.065, P=0.009) and NVD bleeding (OR=6.048, P=0.001) patients.ConclusionYounger age and NVD bleeding are the important risk factors for PVH after minimal vitrectomy without endotamponade in PDR.
Objective To investigate the retinal toxicity and verify the safe dose of intravitreal injection of nonsteroid anti-inflamatory drug,diclofenac sodium.Methods Twenty-eight healthy adult white rabbits were divided at random into 7 groups and received in every right eye the intravitreal injection of a single dose of diclofenac sodium solution ranging from 0.4-0.1 mg/0.1ml respectively ,the left eyes were regarded as conreol ones.Before injection and on the 1st,3rd,7th,14th,21st,and 28th day after injection the electroretinography on both eyes was examined.On the 28th day after injection the retinas of two rabbits of every group were examined by using light microscopy.On the 10th and 30th day after injection the retinal tissues around the optic nerve sisk of two eyes from every group at random were tested by using transmission electron microscopy.Results The retio of amplitude ofb wave of electroretinography in 0.4mg and 0.5mg groups had no sighnificant difference from groups before injection,the retinal tissues showed no structural changes in light and ecectron microscopy examination.The ratio of amplitude ofb wave of photoptic electroretinogrphy in 0.6mg groups in the early stage after injection was markedly reduced（P＜0.05）and returned to that before injection with time,reversible change of the edematou retina was discovered.The ratio of amplitude of b wave of electroretinography in 0.7-1.0mg groups was distinctly descreaded after injection（P＜0.05 or P＜0.01）,the cells of all the retinal layer revealed apparent and irreversible damage.Conclusion The largest dose of safety of intravitreal diclofenac sodium should be not more than 0.6mg.The toxic effect of intravitreal diclofenac sodium on retina is concerned mostly to cones and rods.
ObjectiveTo investigate the effects of thrombospondin-1 active fragment (TSP-1) synthetical peptide VR-10 on proliferation and migration of rhesus choroidal-retinal endothelial (RF/6A) cell and the expressions of apoptosis relative genes in RF/6A cell. MethodsThe survival rate of RF/6A cell were detected by methyl thiazolyl tetrazolium, and migration ability was measured by transwell chamber after exposure to 1.0 μg/ml TSP-1 and synthetic peptide VR-10 (0.1, 1.0, 10.0 μg/ml) for different times (6, 12, 24, 48 hours). Caspase-3 and factor associated suicide (FAS) protein levels were measured by Western blot. The mRNA level of bcl-2 and FAS ligand (FASL) were measured by reverse transcription-polymerase chain reaction (RT-PCR). ResultsThe survival rate of RF/6A cells was determined by the treatment time and concentration of TSP-1(1.0 μg/ml) and the synthetic peptide VR-10 (0.1, 1.0, 10.0 μg/ml). The lowest survival ratio of RF/6A was 78% (P < 0.001) when cells were treated by 10 μg/ml synthetic peptide VR-10 after 48 hours. TSP-1 and synthetic peptide VR-10 could inhibit migration of RF/6A cells in transwell chamber (P < 0.001). 10.0 μg/ml synthetic peptide VR-10 had the strongest effect, 1.0 μg/ml TSP-1 was the next. Migration inhibition rate was increase with the increase of the concentration of VR-10 (P < 0.001). There was no significant differences between 0.1 μg/ml and 1.0 μg/ml VR-10 (P=0.114). Western bolt showed that RF/6A cell in control group mainly expressed the 32×103 procaspase-3 forms. To 10.0 μg/ml VR-10 treated group, it showed decreased expression of procaspase-3 (32×103) and concomitant increased expression of its shorter proapoptotic forms (20×103). Compared with control group, expression of FAS peptides were significantly increased in 10.0 μg/ml VR-10 treated group. Compared with control group, expression of FasL mRNA was significantly increased in 10.0 μg/ml VR-10 treated group(t=39.365, P=0.001), but the expression of bcl-2 mRNA was decreased(t=-67.419, P=0.000). ConclusionTSP-1 and synthetic peptide VR-10 had the ability to inhibit proliferation and migration of endothelial cell, and also induce apoptosis by increasing FAS/FASL expression and repressing bcl-2 expression.
Objective To inverstingate the effect of perfluorohexyloctane(F6H8)to the retina of rabbit eyes. Methods Fifteen vitrectomized New Zealand white rabbits were injectedF6H8(experiment group,12 rabbits ) and BSS(control group,3 rabbits) into vitreous cavity.Slit-lamp biomicroscopy and indirect ophthalmoscopy were performed pre- and postoperatively in all the eyes.Histopathological examination was done after the rabbits were sacrificed at the end of the study. Results A large clear balb was formed after intravitreal injection of theF6H8 in the vitreous was injected and no retinal detachment and cataract were found.The OPL was edematous and then thinned out in 4th week in experimental group.Degenerating cells was found in inner and outer nuclear layers.Cellular vaculoar degeneration was present in TEM. ConclusionF6H8 in vitreous cavity may cause significant side effects on retina,we could not recommend it to be used as an intraocular temponade.