To investigate the processes of retinal vascular development of human fe- tus. METHODS:Eighty-six specimens of retinas of human fetus from 13th to 38th gestational week were studied by immunohistochemieal method(ABC). RESULTS:The spindle cells of mensenchymal origin was firstly found to migrate into the retina from optic disc at 12--13 weeks ,and spreaded subsequently toward the periphery of the retina. At the same time ,the consequential processes of differentiation,proliferation,canalilization and remodelling developed into vascular plexus in ganglion cell layer (GCL). Vascular buds formed in GCL in 26th gestational week extended toward nerve fiber layer (NFL)and inner nuclear layer(INL)and developed into capillary plexuses in NFL and inner and outer margin of INL respectively. CONCLUSIONS.. Four vascular layers could be distinguished in the ratina of full term fetuses,and these layers were formed through two principal developmental processes. （Chin J Ocul Fundus Dis,1996,12: 88- 90）
One eye each in 3 groups of 12 pigmented rabbits after bilateral vitrectomy received 0.5mg, 1mg or 2mg triamcinolone acetonide (TA), respectively. The fellow eye received only balance saline solution as control. Ophthalmoscopy and electroretinography were performed during 1 day to 38 days after vitrectomy and drug injection. Light and electronmicroscopic studies were done on the 28th day. The particles of drug were visible on day 28 in all TA-treated eyes. Administration of 0. 5rug and 1mg TA did not result in different changes in ERG b-wave amplitudes compared with those in control eyes(P＞0. 05). There were significant elevations of ERG b-wave in 2mg TA eyes compared to the control eyes(Plt;0.05), Both ligbt and electronmicroscopy of the retina in these groups were almost normal. The results showed no Toxielties in TA treated eye up to 2mg after vitrectomy. This offers the experimental evidence as a baseline for combining TA with vitrectomy to reduce recurrence of proliferative vitreoretinopathy. （Chin J Ocul Fundus Dis,1996,12: 105- 107）
Purpose:To evaluate the function of gap junction-mediated intercellular communication in cultured cells of retinal pigment epithelial(RPE) cells from porcine eyes. Methods:The cultured RPE cells were previously stained by a fluorescent probe 5, 6-carboxy fluorescein diacetate (CFDA) ,and then photobleach the fluorescent molecule in chosed cells. Using laser scanning confocal microscope (LSCM)to observe fluorescence recovery rate of the RPE cells which located in different condition. The function of gap junction communication was evaluated according to the fluorescence recovery rate. Results:The fluorescence recovered after photobleached and the fluorescent density of cells which touching to them descend. The recovery rate per minnte of the cells which the cell number it adjacent to was 1,2 and 3 respectively was 1. 997plusmn;0. 665, 4. 378plusmn;0. 811 and 8. 736plusmn;2. 084. Conclusion:The cultured porcine RPE cells have the function of gap junction communication,and its function proportion is associate to its adjoining cells number. （Chin J Ocul Fundus Dis,1996,12: 41-42）
Objective To evaluate the efficacy and its affecting factors of silicone oil as an introocular tamponade for copmlicated retinal detachments in children(le;14 years). Methods We analysed retrospectively 34 cases(36 eyes) of complicated retinal detachments in children, who were performed with pars plana vitrectomy combined with silicone oil tamponade from June 1993 to November 1997. Results After 3-21 months of follow-up, the detached retinas in 19 eyes(52.7%) were reattached, in 10 eyes(27.8%) partially reattached and in 6 eyes (16.7%) redetached, 1 eye(2.8) had a media opacity that precluded evaluation of the retina. Postoperative visual acuity was less than 0.05 in 12 eyes(33.3%), and 0.05-0.2 in 20 eyes(55.6%), 2 cases(4 eyes) could not tell their visions(11.1%). Conclusion Silicone oil tamponade is an effctive therapy for complicated retinal detachments in children. The major cause of surgical fai;ure was development of recurrent proliferative vetrioretinopathy. (Chin J Ocul Fundus Dis,1999,15:7-8)
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 clinical effect of conventional vitrectomy using transconjunctival sutureless 20 Gauge (20G) trocar. Methods The clinical data of 62 patients (63 eyes) who had undergone vitrectomy were retrospectively analyzed. The patients were divided into 2 groups according to the surgery methods. Group A: conventional vitrectomy using transconjunctival sutureless 20G trocar were performed on 33 cases (34 eyes) including 19 males (20 eyes) and 14 females (14 eyes). The patients aged from 17 to 75 years with the average age of 52.3 years. The average visual acuity was 0.04 and the average intraocular pressure was 18.25 mm Hg (1 mm Hg=0.133 kPa). Included were 13 cases of diabetic retinopathy, 9 cases of vitreous hemorrhage, 2 cases of silicone oil removal and tearing membrane off, 9 cases of complex retinal detachment, and 1 case of tearing epiretinal macular membrane. Group B: 20G conventional incision vitrectomy was performed on 29 cases (29 eyes) including 13 males (13 eyes) and 16 females (16 eyes) aged from 24 to 69 years with the average age of 49.5 years. The average visual acuity was 0.02 and the average intraocular pressure was 17.50 mm Hg. Included were 10 cases of diabetic retinopathy, 8 cases of vitreous hemorrhage, 5 cases of retinal detachment, 2 cases of longstanding retinal detachment performed with vitrectomy and scleral buckling, and 4 cases of silicone oil removal and tearing membrane off and intravitreal injection of expanding gases. Within group A, 21 eyes were treated with intraocular laser photocoagulation, 9 eyes were treated with scleral cryosurgery to block the hole, 3 eyes were treated with intravitreal injection of expanding gases, and 15 eyes were injected with silicone oil. Leakage of incision, incidence of iatrogenic holes and comfort of patients after operation were recorded and analyzed. All data were analyzed by chi;2 test statistical analysis. Results In group A, 31 eyes had a good degree of comfort without incision leakage and did not need special treatment; 3 eyes filled with inert gas needed suppression for 3 to 5 minutes, and had gas spill from the temporal incision, which needed to be sutured once. In group B, all incisions were sutured with 8.0 silk suture without any incision leakage, whileforeign body sensation and irritation was apparent. Difference on the degree of comfort in the two groups was statistically significant (chi;2 =50.56,Plt;0.01). No eyes in group A generated iatrogenic hole, while 2 eyes in group B generated ora serrata slit pores next to the puncture. Compared with each other, there was a significant statistical difference (chi;2=4.15,Plt;0.05). Conclusion Conventional vitrectomy using transconjunctival sutureless 20G trocar made the vitrectomy simpler and quicker and can reduce the incidence of iatrogenic hole significantly.
Purpose To study changes of cell cycle of vascular endothelial cell in non-proliferative diabetic retinopathy. Methods Alloxan induced Wistar-rats were employed and immunohistochemistry,Western blotting methods were used. Results The vascular endothelial cells of retinas of 8～20 weeks diabetic rats were observe to be cyclinD1,cyclinD3,cyclinB1,p21 and p27 positive stained with light and electronmicroscopies.CyclinE immuno-stained vascular endothelial cells was observed occasionally.Meanwhile,the evidences of morphologic changes of the vascular en dothelial cells were proved:less plasma,thinner cell,more bubble organelles than those of controls.But,the ultra-structures of pericytes and other type of retinal cells did not change and they also immunostain negative.Komas blue and Western blotting methods also proved that the vascular endothelial cells of retina of 20th week diabetic rats expressed cyclinD1,cyclinB1,p21 and p27 protein. Conclusion Glucose induced retinal vascular endothelial cells of 8～20th weeks diabetic rats enter cell cycle and were arrested at G1/S restriction point.This study also suggested that retinal vascular endothelial cells may possess the ability to resist glucose damage and mechanism of selfstability during very early stage of diabetes. (Chin J Ocul Fundus Dis,2000,16:173-176)
OBJECTIVE :To investigale effect of subretinal fluld(SRF)on proliferalion of the cellular elements of PVR. METHOD:The effect of SRF of 28 patients with rhegmatogenous retinal detachment proliferation of the cultured human retinal pigment epithelial cells(RPE),retinal glial cells (RG),and fibroblast (FB)was observed and detected by the methods of cell-counting and 3H-TdR in DNA synthesis. RESULTS:The range of proliferatinn-stimulating activity was 52.5%~233.3%, 36.4% ~ 177.8%，55.4% ~277.8% above the baseline in 1:10 dilution of these 3 kinds ,of cellular elements,and there was no significant difference among them. CONCLUSION ;The stimulating effect of SRF on the cellular proliferation was thougt to be due to the actions from certain growth factors. （Chin J Ocul Fundus Dis,1996,12: 233-235）
OBJECTIVE :To investigate ocular vessel flow velocity in normal eyes by color Doppler imaging(CDI). METHODS: Ninety people (180 normal eyes)had flow velocity measured by CDI in three vessels,ophthalmic artery (OA),central retinal artery(CRA) and posterior ciliary artery (PCA),and the relations between velocity and affecting factors were analysed. RESULT: The diastolic and systolic velocity of OA,CRA and PCA were (31.7plusmn;10.9)cm/s, (7.2plusmn;2.6)cm/,s, (10.2plusmn;3.4)cm/s, (2.8plusmn;1.2)cm/s and (11.3plusmn;3.6)cm/s, (3.2plusmn;1.4)cm/s respectively. The velocity of OA had possitive correl-ativity with RBC,HCT and negative correlativity with age,while it revealed no relationship with sex, laterality of right or left eye,and normal IOP. CDI of ocular vessels in normal eyes is a triangle with three peaks and double sunkens in its frenquency spectum, revealed highly resistant,and both the pulsatility and resistive indexes were relatively high. The width of each frequency band basically was the same,and there was no obvious frequency window. CONCLUSION: The ocular application of CDI might lay the foundation of a comparatively comprehensive knowledge of the ocular hemodynamics. （Chin J Ocul Fundus Dis,1997,13: 99-101）
ObjectiveTo investigate the impact of L-Phenylalanine on the efficiency of retinal pigment epithelial (RPE) cell derivation from human embryonic stem cells (hESCs) and explore the underlying mechanisms. MethodsH1 hESCs were routinely cultured with mTeSR medium and divided into control and experimental groups. When cells reached over-confluence, spontaneous differentiation was triggered using 10% KSR differentiation medium without bFGF. L-Phenylalanine (0.2 mmol/L) was supplemented in the experimental group from the 3rd week. The expression of RPE markers and Wnt signaling components in the two groups was detected by Real time-RCR, Western blot and Flow cytometry analyses. Purified hESC-RPE cells and PBS were injected into the subretinal space of sodium iodine-induced retinal degeneration rats separately. Retinal function was assessed by ERG 6 weeks after the transplantation. ResultsOn the 7th week, much more pigment cell clumps appeared in the experimental group compared to the control group. Within these areas there were monolayer hexagonal RPE cells full of pigment granules. The experimental group showed significantly higher expression of Pax6, MITF, Tyrosinase, RPE65, Wnt3a, Lef1 and Tcf7 genes than the control group (P < 0.01). Higher expression level of MITF and RPE65 proteins and higher percentage of RPE65 (+) cells (P < 0.01) were detected in the experimental group. 6 weeks after sub-retinal transplantation of hESC-RPE cells, the amplitudes of a-b wave in the transplanted eyes were significantly higher than those in the control eyes (P < 0.01) at the stimulus intensity of 3.0 cd·s/m2. ConclusionsL-Phenylalanine effectively promoted the differentiation of embryonic stem cells into retinal pigment epithelial cells, and its impacts on the Wnt/β-catenin signaling pathway may partially explain the underlying mechanisms. Subretinal transplantation of hESC-RPE remarkably improved the retinal functions of retinal degenerative animal models.