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.
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 observe the effect of medicineinduced posterior vitreous detachment (PVD) on proliferative vitreoretinopathy (PVR). Methods PVR was induced in the left eyes of 24 pigmented rabbits by intravitreal injection with platelet rich plasma. The rabbits were randomly divided into two experimental groups (group A and B) and one control group with 8 eyes in each group. Three hours later, the eyes in group A and B and the control group underwent intravireal injection with 1 U plasmin 0.05 ml+20 U hyaluronidase 0.05 ml, plasmin 0.1 ml, and balance salt solution 0.1 ml, respectively. The grade of PVR was recorded 1, 7, and 28 days after the intravitreal injection, and the eyes were examined by flash electroretinogram (FERG), B-scan, and retinal histopathological examination. Results The PVR models of rabbit eyes were induced successfully. On the 7th day after injection, complete and partial PVD was found in 5 and 3 eyes respectively in group A; partial PVD in 5 eyes and no complete PVD was observed in group B; there was no PVD in the other 3 eyes in group B and also in the eyes in the control group. On the 28th day after intravitreal injection, PVR grade of group A and B were both obviously lower than that of the control group（D=75.6, 98.9；P=0.003，P=0.011）; On the 7th and 28th day after injection, the b-wave amplitude in group A and B was significantly higher than that in the control group; PVR grade of the PVD eyes was lower than that of nonPVD eyes; PVR grade of the complete PVD eyes was only 0～1. Conclusions Three hours after the PVR models of rabbit eyes were induced, complete PVD induced by intravitreal injection of plasmin combined with hyaluronidase could prevent the development of PVR of rabbit eyes in some degree; partial PVD induced by plasmin alone or combined with hyaluronidase could relieve the development of PVR.
PURPOSE: To investigate the treatment of severe bacterial endophthalmitis. METHODS:The curative effects of vitrectomy after intravitreal antibiotics and steroids (IVAS)for the treatment of 23 patients with bacterial endophthalmitis (group I)and vitrectomy and IVA at the same time for the treatment of 28 patients with bacterial endopbthalmitis (group I)were analyzed retrospectively. RESULTS: The rate of curative effects of two groups were similar,while the marked curative effects in group I (47.8% )was significantly higher than that of the group I (17.9%). The average period of eliminating infiamation of group I was longer than that of group I , and the incidence of postoperative retinal detachment of group Ⅱ was 3 times more than that of group I . CONCLUSION :It was indicated that vitrectomy after IVAS may increase the security of vitrectomy and the curative effects of severe bacterial ndophthalmitis.
Objective To investigate the protective effect and mechanism of erythropoietin (EPO) on injury of human retinal pigment epithelial (hRPE) cell induced by hydrogen peroxide (H2O2). Methods Take subcultured hFRPE cells as study target. They were treated with 800 mu;mol/L of H2O2 for 3 hours to establish the cell injury model. The cultured cells were divided into three groups：control group, simply injury group and therapeutic group which again divided into 10 IU/ml, 20 IU/ml, 40 IU/ml,60 IU/ml subgroups according to the concentration of recombinant human erythropoietin(rhEPO). NF-kappa;B was measured by immunohistochemistry. The content of Malondialdehyde(MDA) which was the product of cellular lipid peroxidation and the releasing rate of lactate dehydrogenase（LDH）were estimated by chromatometry. Results H2O2 could elevate the level of MDA and the releasing rate of LDH, compared simply injury group with control group, the differences were significant.(tLDH＝29.746,tMDA＝20.426,Plt;0.05); Compared all of therapeutics groups with simply injury group, the releasing rate of MAD and LDH were decreased obviously, the differences were significant.（LDH t10IU＝5.770，t20IU＝12.774，t40IU＝19.818，t60IU＝24.833，Plt;0.05；MDA t10IU＝5.345，t20IU＝10.278，t40IU＝18.571，t60IU＝20.247，Plt;0.05）; The correlative analysis results of each therapeutic subgroup were: ①the concentration of rhEPO had negative correlation with the relation rate of LDH and the content of MDA(r=-0.976，P=0.024； r=-0.968，P=0.032) ; ②the concentration of rhEPO had positive correlation with the nuclear translative rate of NF-kappa;B(r=0.998，P=0.002); ③the nuclear translative rate of NF-kappa;B had negative correlation with the content of MDA(r=－0.954，P=0.046). Conclusion EPO can protect hFRPE cells from the injury of H2O2, the mechanism may be related to the activation of NF-kappa;B.
Objective To observe the regulation effect of transforming growth factor alpha (TGFalpha;) on expression of glutamate transporter（GLAST）and ingestion activity of retinal Muuml;ller cells in mice. Methods To take the retinal tissue of Kunming mouse at postnatal 7～10 day, and then cultured Muuml;ller cells according to literature. The 3～4 generation cultured cells of the same primary cell were divided into two groups at random: ① TGFalpha; group: maintained in different concentrations of TGFalpha; as 50, 75, 125 and 150 ng/ml, 3 holes in each concentration;② Control group: cultured by Eagle culture medium which improved from Dulbeccon and contained 20% fetal calf serum. The influence of different concentrations TGFalpha; on GLAST activity in Muuml;ller cells were observed by L-3H-glutamate uptake detection; the expression of GLAST mRNA in Muuml;ller cells was determined by RT-PCR; the expression of GLAST protein was detected with immunocytochemical staining. Results With the increase of TGFalpha; concentration, both L3H glutamate uptake and GLAST mRNA expression were increased. The L-3H-glutamate accumulation had got to the maximum uptake at concentration of 125 ng/ml, which was 266% of that in control group, meanwhile, the expressions of GLAST mRNA also got to the maximum as 4 times of control group. Immunocytochemical staining indicated that the effect of 125ng/ml TGFalpha; on expression of GLAST protein was higher than that in the control group, the differences between two groups were statistically significant (Plt;0.05). Conclusion TGF-alpha; can increase GLAST activity through up-regulating the expression of GLAST mRNA and protein.
Objective To investigate the retinal toxicity and verify the safe dose of intravitreal injecting fluconazole. Methods Twelve healthy adult white rabbits were divided at random into 6 groups：a normal control group and 5 groups received intravitreal injection of a single dose of fluconazole ranging from 10 to 200 mu;g respectively.Retinal toxicity was examined by ophthalmoscopy, electroretinography, light and transmission electron microscopy (TEM) on the third and fourteenth day after injection. Results The ultrastructures of the retinal tissues of the normal control group and fluconazole 10～150 mu;g groups were normal on the third and fourteen day after injection.The light microscopy and TEM showed that cells of all the retinal layers in the 200 mu;g group revealed apparent degenerative changes on the fourteenth day after injection, and the light microscopic picture showed the vacuolar degeneration of outer segments of photoreceptors, the nuclei in outer nuclear layer drop out into inner segments, the vacuolar degeneration of nerve fiber layer, and the proliferation of pigment epithelium. TEM revealed expansion of paranucl eus space and karyopyknosis of the bipolar cells, the swelling of nerve fibers and disappearance of the synapses in the inner plexiform layer, the vacuolation and disappearance of microvilli of the pigment epithelium cells. Conclusion The safe dose of fluconazole injected intravitreally should be 100～150 mu;g. (Chin J Ocul Fundus Dis，2000，16：139-212)
Objective To observe the effects on rabbit corneas and retinas after single intravitreal injection of voriconazole at different doses. Methods According to the randomization table, 25 healthy rabbits were randomly divided into control group, and voriconazole 50, 100, 200, and 400 μg groups. Therefore, there were 5 rabbits in each group. The eyes of control group received intravitreal injection of 0.1 ml balanced saline solution, and those treatment groups received 0.1 ml voriconazole injection of corresponding dose. Before the injection and 1, 7, and 14 days after the injection, endothelial cell counts and corneal thicknesses were measured; full-field electroretinogram were performed and b-wave amplitudes in maximal combined reaction (Max-R) were recorded. On 14 days after the injection, histologic structures were observed by light microscope and transmission electron microscope. Results There was no significant difference in endothelial cell counts (F=0.320, 0.291, 0.467, 0.649) and corneal thicknesses (F=0.214, 0.284, 0.360, 0.225) with those of control group at any time points (P > 0.05). Before and 1 day after the injection, b-wave amplitudes of each voriconazole group had no significant difference compared with those of control group (F=0.220, 0.106; P > 0.05). On 7 days after the injection, b-wave amplitudes decreased significantly at doses of 200 μg and 400 μg (P < 0.05). On 14 days after the injection, there was no significant difference between the the amplitude of 200 μg group and that of control group (P > 0.05). However, the amplitude of the 400 μg group decreased continuously and there was still significant difference (P < 0.05). Light microscopy did not reveal any corneal abnormality in both control group and voriconazole groups. The retinas were normal except that of the 400 μg group, which hadathinner and degenerated inner nuclear layer and disordered photoreceptor layer. Under transmission electron microscope, there were no ultrastructure damages of corneas in both control group and voriconazole groups, either. The rabbit retinas of the 50 μg and 200 μg group have normal inner nuclear layer and photoreceptor layer, but degrees of changes in both layers were observed in the eyes of 200 μg and 400 μg group. Conclusions There is no obvious effects on rabbit corneas and retinas after single intravitreal injection of voriconazole at he dose less than or equal 100 μg. There are no obvious effects on rabbit corneas at the dose of 200 μg and 400 μg, while there are damages to the retinas in both functions and histological structures.
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 evaluate the security of intravitreal injection with ciproflaxacin to retina.MethodsTweenty-four rabbits were randomly divided into 4 groups with 6 rabbits in each group. 0.1 ml ciproflaxacin in doses of 2 500,5 000,and 10 000 μg was intravitreally injected into the rabbits eyes, retrospectively. And 0.1 ml saline solution was injected into the vitreous body of the rats in the control group. Indirect microscope, light microscope and electroretinogram (ERG) were used to observe the changes of ocular fundus.ResultsNormal results of light microscopy and ultrastructure were found in 250 μg and 500 μg groups; irregularly arranged outer and inner nuclear layers, dropsical or even lost ganglion cells, and ultrastructural changes were in 1 000 μg group. There was no apparent difference of ERG′s a and b amplitudes before and after intravitreal injection with ciproflaxacin in each group.ConclusionIntravitreal injection with ciproflaxacin is safe, and 500 μg or less is the secure dosage in rabbits' eyes. (Chin J Ocul Fundus Dis, 2005,21:180-182)