Intravitreal fibrin clots were produced by intravitreal injection of 0.2 ml autologous plasma in 18 rabbit eyes. Subsequently these eyes were treated by intravitreal injection of either tissue plasminogin activator(t-PA) or saline. In the t-PA(12.5mu;g) group(n=10),intravitreal fibrin clots of 6 eyes cleared up within 6 hours, and that of the other 4 eyes within 1 day. In the saline group( n=7), the complete clearallce was not seen after 7 days. The difference of time between two groups was significant ( P＜0. 05), and no evidence of toxic effect was observed as measured by slit-lamp biomicrocopy, ERG, light microcopy and transmission electron microscopy.One eye treated with 100mu;g t-PA also resulted in a total clearance within 6 hours,but retinal toxicity was demonstrated with ophthalmoscopy and light microscopy. （Chin J Ocul Fundus Dis,1994,10:14-16）
Abstract: Objective To investigate the messenger ribonucleic acid (mRNA) expression level of tissue-type plasminogen activator (t-PA) in endothelial cells derived from adult mesenchymal stem cells (MSCs) after fluid shear stress loading which is within the physiological range. Methods After culturing in vitro, bone marrow MSCs of SD rats were seeded on slides.When it come to 80% confluence,26 slides were exposed to 5dyn/cm2 fluid shear stress for 3h in a flow chamber, and then induced to endothelial cells. Among them,13 slides constituted group Ⅰ, and the rest 13 slides set up group Ⅱ, which would be cultured for 3-4d further and passaged in 1∶3. At the same time, control group was set up, which including the cells never exposed to fluid shear stress before the endothelial differentiation. Fluid shear stress were exerting to cells in a specially made flow chamber. The expression level of t-PA mRNA of all groups were measured by real-time fluorescent quantitation reverse transcriptionpolymerase chain reaction (RTPCR). Results After endothelial differentiation for 7 days, the SD rats bone marrow MSCs acquired typical endothelial cell appearance. The t-PA mRNA expression level of group Ⅰ and group Ⅱ have an obviously enhance compared with control group(P＜0.05). The t-PA mRNA expression level of group Ⅱ step down a little (P＞0.05), but it is still significantly higher than that of control group (P＜0.05). Conclusion Fluid shear stress could provide a protective action on the endothelial cells induced from MSCs in vitro, and the effect maintains with the cells passages. This formulates a theoretical foundation to the therapeutics of atherosclerosis and selection of seed cells in vascular tissue engineering.
Objective To detect the effects of plasmin combined with hyaluronidase or hexafluoride SF6 on inducing posterior vitreous detachment (PVD). Methods Eighteen young pigmented rabbits were randomly divided into group A, B, and C with 6 rabbits in each. All of the right eyes were the experimental eyes and the left ones was the control. The right eyes in group A, B, and C were injected with plasmin 1 U, plasmin 1 U and hyaluronidase 20 U, and plasmin 1 U and SF6 0.5 ml, respectively; while all of the left eyes underwent intra-vitreous injection with balanced salt solution 0.1 ml. The eyes were observed by indirect ophthalmoscopy, slit lamp examination, biomicroscopy, B-ultrasonography, and electroretinography (ERG) before and after injection respectively. At last, the retinal sections were examined by light microscopy, scanning and transmission electron microscopy. Results The results of scanning microscopy showed incomplete PVD in 2 (33.3%) experimental eyes in group A, and complete PVD in 4 (66.7%) experimental eyes in both group B and C, and the positive rate of PVD in both group B and C significantly differed from that in group A (Plt;0.05). The b-wave amplitudes of ERG in the three groups after injection didn’t differ much from that in the control group or before the injection（Pgt;0.05）. The results of transmission electron microscopy and light microscopy indicated unchanged retinal structure. Conclusions Compared with the application of only plasmin, plasmin combined with hyaluronidase or hexafluoride SF6 can induce complete PVD more efficiently and do no harm to the retina. (Chin J Ocul Fundus Dis, 2005, 21: 388-390)
Objective To observe the suppressive effect of co mbi nation of tissue plasminogen activator (t-PA), heparin and homoharringtonine on the formation of proliferative vitreoretinopathy (PVR) after vitreoretinal surgery. Methods Forty-three cases (44 eyes )of complicated retinal detachment who received vitreoretinal surgery were divided into 2 g roup s.Twenty cases(20 eyes)in group A were treated by intravitreal injection of abo ve mentioned drugs at the end of operation,while no intraocular injection of drugs given in 23cases(24 eyes)in group B.The mean follow-up period was 7.9 months. Result The rate of recurrent PVR in group A was 15.8%(3 of 19),and 45.5%(10 of 22) in group B (P＜0.05). The rate of recurrent retinal detachment was 5.5%(1 of 18) in group A,an d 33.3%(7 of 21) in group B，in group B(P＜0.05). Conclusion Combination use of the above mentioned drugs can effectively suppress the post operative recurrent PVR and lower the rate of subsequent recurrent retinal detac hment. (Chin J Ocul Fundus Dis, 2001,17:24-25)
Objective To determine whether kringle 4-5 could inhibit choroidal neovascularization (CNV) in mice induced by argon laser photocoagulat ion. Methods Fundus laser photocoagulation was performed on C57BL/6J mice to induce CNV. In treatment group, 20 μg (low dosage group) and 50 μg (high dosage group) kringle 4-5 were injected retrobulbarly after photocoagulation. In control group, equilibrium liquid was injected retrobulbarly. Choroidal neovascularization was evaluated on the 7th and 14th day after photocoagulation by fundus fluorescein ang iography. The mice were killed on the 14th day after photocoagulation, the lesions were evaluated histologically and immunohistochemically, and the expression of CD105 was detected. The Expression of VEGF and bFGF was detected by immunohist ochemistry on the 4th day after photocoagulation.Results The incidence of CNV was 64.3% in control group, 51.2%（P＜0.05）in low dosage group, and 44. 1% (P＜0.01) in high dosage group. The CNV lesions were smaller in kringle 4-5 injected eyes in a dose-dependent manner and the number of proliferative vascular endothelial cells in the subretinal membrane of the treated eyes was smaller than that of the control eyes. There was no significant difference of the expression of VEGF and bFGF between the mice in control and treatment group.Conclus ions Kringle 4-5 could inhibit the development of choroidal neovascularization in the experimental mice model.(Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To investigate the dosage, efficacy and safety of intrav itreal injection of plasmin in producing posterior vitreous detachment (PVD), an d the possible role of plasmin in degrading adhesion glycoproteins of inner limiting membrane (ILM).Methods Twenty eyes of young human cadavers within 24 hours after death were divided into 4 groups that received 0.1 ml balanced salt solution (group 1) as control, 1 (group 2), 2 (group 3), or 3 (group 4) U of human plasmin. Optical and transmission electron microcopies were performed to examine the ultrastructure of the vitreoretinal interface. Electron-immunocytochemical techniques were carried out on ILM to estimate the content of fibronectin (FN) and laminin (LN). Flow cytometry was used for cell viability analysis of variance (ANOVA) and Tukey-test was employed for statistical analysis. Results Microscopy demonstrated that plasmin especially in group 4 cleaved the attachment of the vitreous collagen fibrils to the ILM with no evident damage to the inner retina. The content of LN, FN in ILM decreased with injection of plasmin (group 3 and 4 had statistical significance from control group for FN,P＜0.05; for LN in group 4, P＜0.05). Retinal cell viability was similar for plasmin-treated and control eyes. Conclusion Human plasmin disrupts the attachment of posterior hyaloid to the ILM with no morphologic changes of the inner retina. PVD is induced mostly with injection of 3 U plasmin. (Chin J Ocul Fundus Dis，2003，19：42-45)
Objective To observe the effects of intravenous thrombolysis with urokinase for central retinal artery occlusion (CRAO). Methods A total of 115 CRAO patients diagnosed by fluorescence fundus angiography (FFA) were enrolled in this study. The patients included 61 males and 54 females, with a mean age of (56.7plusmn;15.2) years (from 41 to 75 years). The duration ranged from 1 to 30 days. All the patients were affected unilaterally. All the patients were received the treatment of intravenous thrombolysis with urokinase (3000 U/kg, two times per day, continuous treatment for six to seven days) and retrobulbar injection of dexamethasone 2.5 mg (one time per day, continuous treatment for 14 days). Following that, 1.2 mg/kg brain protein hydrolysate (nerve nutrition) and 360 mg troxerutin (vasodilator) were given by intravenous drip (one time per day, continuous treatment for 14 days). Effectiveness of the thrombolytic and subsequent treatments including the recovery of vision and retinal arterial filling time before and after treatment were observed. Comparing the visual acuity of post-treatment and pre-treatment, improving three lines or more is considered as effective markedly, improving two lines as effective, no change or a decline as no effect. With FFA as the retinal circulation recovery index, the arm-retinal circulation time (A-Rct ) le; 15s and all branches of central retinal artery were filled with fluorescence within 2s filling (normal) as effective markedly; A-Rct improved but was in 15 - 20s range, all branches of central retinal artery were filled with fluorescence within 3～8s as effective; A-Rct improved but was still ge; 21s, all branches of central retinal artery were filled with fluorescence within ge;9s as no effect. The relationship between age, gender, the disease course, subsequent treat time and curative effectiveness were analyzed. Results There were 79 patients were examined for FFA again after thrombolysis treatment which including 11 patients with complete obstruction and 68 patients with incomplete obstruction. In 11 patients with complete obstruction, eight patients showed that optic disc vascular retrograde filling disappeared, A-Rct was 28-54s, and the filling time from retinal artery to tip was 18 - 55s; three patients showed persistent optic disc vascular retrograde filling within 3 - 4 minutes of FFA. In 68 patients with incomplete obstruction, A-Rct returned to normal in 35 patients (51.4%), effective in 18 patients (26.5%) and no effect in 15 patients (22.1%). Retinal circulation time was shorter than that before thrombolysis treatment (chi;2=11.4, Plt;0.05). Comparison of distribution of visual acuity before and after thrombolysis treatment, the difference was statistically significant (chi;2=12.1, Plt;0.05). Comparison of distribution of final visual acuity after subsequent treatment with that of after thrombolysis treatment, 48 eyes improved two lines or more, the efficiency was 41.7%, the difference was statistically significant (chi;2=14.6, Plt;0.05). Comparison to that of before treatment, vision changes showed effect markedly in 58 patients (50.4%), effective in 35 patients (30.4%), no effect in 22 patients (19.2%), the difference was statistically significant (chi;2=44.5, Plt;0.05). Comparison the average age to that of effective, valid and invalid patients, the difference was not statistically significant (t=0.98, 1.17, 0.55; Pgt;0.05). There was no relationship between effectiveness and gender (chi;2=2.6, Pgt;0.05). In 76 patients with duration within seven days, 43 patients were effective markedly and 22 patients were effective, the efficiency was 85.5%. In 25 patients with duration of 8 - 15 days, 11 patients were effective markedly and eight patients were effective, the efficiency was 76.0%. In 34 patients who received subsequent treatment 8 - 14 days, 18 patients were effective markedly and nine patients were effective, the efficiency was 79.4%. In 51 patients who received subsequent treatment 15-21 days, 27 patients were effective markedly and 18 patients were effective, the efficiency was 88.2%. Conclusion Intravenous thrombolysis with urokinase was effective in the treatment of CRAO.
Objective To observe the therapeutic effects of vitrectomy combined with tissue plasminogen activator(r-tPA) and fraxiparine on bacterial endophthalmitis. Methods Forty pigmented rabbits were randomly divided into experimental and control group with 20 rabbits in each. The left eyes underwent intra-vitreous injection with 10 5/ml bacteria of staphylococcus epidermidis 0.1 ml. After 8-4 hours, vitrectomy was performed on all of the animals. Fraxiparine with the final concentration of 6 IU/ml was only added to balanced salt solution in the experimental group during the operation, and the extend of intraocular fibrin exudation was observed by slit lamp and indirect ophthalmoscope after the operation. If the exudation occurred on the 1st, 3rd, 7th, 14th and 21st day postoperatively, 125 mg/ml r-tPA 0.1 ml should be injected into vitreous from the 1st day after operation on. Results Fibrin exudation in the pupil area and vitreous body was much less in experimental group than that in the control group after the surgery. Conclusion vitrectomy combined with r-tPA and fraxiparine may alleviate the extent of fibrosis in bacterial endophthalmitis and improve the prognosis. (Chin J Ocul Fundus Dis, 2005, 21: 391-393)
ObjectiveTo observe the efficacy and safety of vitrectomy combined with submacular injection of tissue-type plasminogen activator (t-PA), gas filling and anti-VEGF drugs (multiple therapy) for thick submacular hemorrhage.MethodsA retrospective case study. From January 2014 to June 2018, 24 patients (24 eyes) with thick submacular hemorrhage who received multiple therapy at the Department of Ophthalmology of Peking University Third Hospital were included in the study. Among them, there were 15 males and 9 females with the average age of 69.05±8.86 years. The average submacular bleeding time was 17.15±10.30 days, the average bleeding area was 13.85±8.63 DD. Seventeen eyes showed hemorrhagic RPE detachment. The international standard visual acuity chart was used to BCVA examination, which was converted to logMAR visual acuity in statistics. The frequency domain OCT was used to measure the height of the foveal elevation. The average logMAR BCVA of the affected eye was 1.37±0.38. The average height of the macular fovea was 824.94±294.38 μm. All eyes underwent 23G or 25G vitrectomy. During the operation, 0.1-0.5 ml t-PA (10 μg/0.1 ml) was injected under the macula. The vitreous cavity was filled with 15% C3F8 after gas-liquid exchange in 13 eyes, and 11 eyes were filled with sterilized air. Eleven eyes were injected with anti-VEGF drugs at the end of the operation, and anti-VEGF drugs were given PRN treatment according to the activity of the lesion. The average follow-up time after treatment was 27.90±22.21 months. The absorption of bleeding under the macula, the improvement of vision, the occurrence of rebleeding and treatment-related complications were observed and recorded. The Wilcoxon rank sum test was performed to compare the BCVA and the height of foveal elevation before and after treatment.ResultsOne month after the treatment, the blood in the fovea of all affected eyes was cleared. At the last follow-up, the logMAR BCVA and macular foveal elevation were 0.82±0.28 and 253.88±71.75 μm, respectively. Compared with those before treatment, the difference was statistically significant (Z=－3.727, －3.234; P＜0.001, ＜0.001). The average intravitreal injection of anti-VEGF drugs was 1.08 times. During the operation, a tiny hole was formed in the center of the macula when t-PA was injected under the retina. Two eyes showed mild vitreous hemorrhage early after the operation. During the follow-up period, bleeding recurred in 2 eyes.ConclusionsVitrectomy combined with submacular injection of t-PA, gas filling, and anti-VEGF drugs is an optimal combination for the treatment of thick submacular hemorrhage. It can effectively remove submacular hemorrhage, improve vision, reduce foveal elevation with good safety.