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"Si Sheng",including postgraduates,advanced study students,standardized training students and interns,is the main part of teaching work in hospital and department.This article is for meeting the requirement of students and emphasizing all-round preparation of the teaching work and teaching in accordance with their aptitude;pays attention to the combination of various teaching methods,such as training of new technology and new affairs,case discussion,multidisciplinary discussion,standardized teaching rounds and so on;pays attention to collect feedback from students.Those practical works effectively improve teaching quality and standard.
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Objective To investigate the correlation between macular structural changes and functional outcomes in idiopathic macular epiretinal membranes (IMEM).Methods Clinical data of 85 patients with monocular IMEM admitted from April 2013 to April 2014 were retrospectively analyzed.The diseased eyes(85 eyes)were studied as observation group and the normal eyes (85 eyes)served as control group.The results of routine eye examinations,optical coherence tomography (OCT) and multifocal electroretinography (mfERG) were compared between observation and control groups.Results The preoperative best corrected visual acuity (BCVA) in observation group was lower than that in control group (0.55-± 0.17 vs.0.92 ± 0.14,P ＜ 0.05);the eyes with BCVA ＜ 0.1 in observation group were more than those in control group (P ＜ 0.05).The central retinal thickness (CRT) of observation group was higher than that of control group[(322.1 ±54.3) μm vs.(210.3 ±47.5) μm,t =14.29,P ＜0.05].The average response density of N1 wave and P1 wave in observation group were (36.7 ± 19.7) and (95.2 ±24.0) nV/ deg2,which were lower than those in control group [(42.9 ± 16.3) and (134.8 ± 20.1) nV/deg2;t =-2.23 and-11.66,respectively,P ＜0.05].The latent period of N1 wave and P1 wave in observation group were (22.0 ±4.1) and (39.5 ± 4.7) ms,which were lower than those in control group [(18.7 ± 3.0) and (38.0 ± 3.2) ms;t =5.99 and 2.43,respectively,all P ＜ 0.05].The CRT in observation group was not correlated with average response density of macular center N1,P1 wave and latent period (r =-0.23,-0.35,0.06,-0.04,all P ＞ 0.05).BCVA in observation group was negatively correlated with CRT(r =-2.16,P ＜ 0.05).Conclusions The central retinal thickness is negatively correlated with the best corrected visual acuity,but not correlated with center mfERG in patients with IMEM.
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To study proliferation of the retinal pigment epithelium (RPE) after experimental retinal detachment, an antibody that recognizes the specific proliferating cell nuclear antigen (PCNA) in proliferating cells was used. Retinal detachment was produced in cats by subretinal injection of 0 25% solution of Healon through a micropipette. At different intervals the animals were sacrificed and eye globes were fixed in 10% at malin and embeded in paraffin. Histologic sections were processed for immunohistochemisty using an antibody to detect the PCNA protein. Labeled RPE cells were identified, and the proliferative response was quantified. In the retina detached at 0 5, 1, 2, 3, 4, 5, 6, 7, 10, 14, 20, 30, and 60 days, the number of PCNA labled cells was 0 055, 0 444, 0 861, 1 972, 3 139, 5 833, 6 028, 4 917, 3 333, 2 195, 1 083, 0 195, and 0 056 cells per millimeter of retina, respectively. In non detached retina of the same eye, approximately from 0 to 0 639 cells per millimeter of retina were labeled. The difference of PCNA labeled cells between detached and non detached retina of the same eye was significant. These results indicate that RPE cells are induced to proliferate when they lose contact with neural retina.
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Objective To investigate the occurrence, progress and conversion of hypotony in anterior proliferative vitreoretinopathy (aPVR), and to provide knowledge about how to prevent and treat it. Methods Animal models of chronic hypotony by aPVR were made with cultured homologous dermal fibroblasts on pigmented rabbits. The intraocular pressure (IOP) and ultrasound biomicroscopy(UBM) examination were taken preoperatively and on days 7,14, 28 and 56 postoperatively. Rabbits were killed on days 14, 28 or 56 postoperatively, prepared for histology and ultrastructure examination. Results The average IOP of experimental group was lower than that of control group on days 7,14,28 and 56 significantly (P
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Objective To investigate the efficacy and safety of intravitreous injection with triamcinolone acetonide (TA) for cystoid macular edema (CME) due to central retinal vein occlusion (CRVO). Methods Fourteen eyes of 14 patients with CME due to CRVO underwent intravitreous injection with 0.1 ml TA (40 mg/ml). Best-corrected visual acuity, intraocular pressure (IOP), slitlamp examination, fundus fluorescein angiography, and optical coherence tomography (OCT) were performed on the patients before and after the injection. The follow-up period was 10-22.4 months, with the mean of 15.9 months. Results The average visual acuity was 0.1 before the treatment; while 1 month and 3 months after the injection, the visual acuity of all of the patients improved, including ≥0.2 in 71.43% and 63.6% of the patients, respectively, and ≥0.5 in 42.9% and 27.3%, respectively. After then, the visual acuity of some patients decreased, and in the final visit, 4 eyes (28.6%) had a visual acuity of ≥0.2, and 1 eye (7.1%) of ≥0.5. Compared with that before the treatment, the visual acuity of 10 (71.4%) eyes improved and 4 (28.6%) eyes declined. One month after the treatment, the macular edema disappeared in 10 eyes (71.4%) and alleviated in 4 (28.6%). In the final visit, macular edema disappeared in 4 eyes, alleviated in 9, and aggravated in 1. In the follow-up duration, high IOP [22.3-40.1 mm Hg (1 mm Hg=0.133 kPa)]. In the final visit, posterior subcapsular cataract was found in 7 eyes. Conclusion Intravitreous injection with TA may be effective in reducing CME and enhancing the visual acuity in a short term with high IOP in some eyes. In the long-term follow-up period, the rate of recurrence of CME and incidence of posterior subcapsular cataract is high.
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Objective To examine the expression of proliferating cell nuclear antigen (PCNA) of retinal pigment epithelial (RPE) cells, thus assessing the role of mechanism of contact inhibition playing in the process of experimental retinal detachment and reattachemnt. Methods Retinal detachment was produced in 72 cats by subretinal injection of 0.25% solution of healon through a micropipette three weeks after extracapsular lens extraction and vitrectomy. Some of the detached retinae were reattached 24 hours later. At different time, the cats were killed and eye globes were fixed and embeded in paraffin. Histologic sections were processed for immunohistochemistry examination using an antibody to detect PCNA protein. Labeled RPE cells were identified, and the proliferation was quantified in detached and un detached retinae of detachment group, and also in reattached retinae of reattachment group. The comparsion of PCNA labeled RPE cells in different groups were analyzed by ANOVA. Results In detached regions of detachment group, PCNA expression of RPE cells occured within 24 hours, and reached a maximum after 5 6 days, then gradually declined to barely detectable levels after 20 days. Similar tendency was found in reattached retinae, but the number of PCNA labeled RPE cells was obviously small. Fewer PCNA labeled RPE cells were found in regions of un detached retinae in detachment group. The difference of these three groups was significant. Conclusion Proliferation of RPE cells is induced when they lose contact with neural retina, but inhibited after neural retina reattached to RPE cells. It suggests that the mechanism of contact inhibition plays a role in the proliferative process after retinal detachment and reattachment.
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Objective To study the occurrence, development and outcome of hypotony following traumatic anterior proliferative vitreoretinopathy (aPVR), so as to provide a theoretical basis for its prevention and treatment. Methods An animal model of chronic hypotony following traumatic aPVR was reproduced in rabbits. The intraocular pressure (IOP) was measured before the experiment and on days 7, 14, 28 and 56 after the injury. Rabbits were killed on days 14, 28 and 56 after the experiment, prepared for pathological and ultrastructure examination. Results The average IOP of experimental group was significantly lower than that of control group on days 7, 14, 28 and 56 (p
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Objective To study the dynamics of aqueous humor in chronic hypotony induced by traumatic anterior proliferative vitreoretinopathy (aPVR), and to demonstrate physiologic mechanisms of the hypotony. Methods A model of hypotony to simulate traumatic aPVR was reproduced in rabbits. Preoperatively and on day 7, 14, 28 and 56 postoperatively, the aqueous humor flow rate and the uveoscleral outflow of aqueous humor were determined. Results The flow rate of aqueous humor in experimental group was reduced remarkably compared with that of control group on days 14, 28 and 56 (P
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To investigate the effectiveness and safety of systemic administration of high dose urokinase for acute central retinal artery occlusion (CRAO). 6 patients who had unilateral CRAO with symptoms lasting 6 hours to six days' (average, 3 7 days) received intravenous urokinase, 500,000U / day, with a total dose of 2,500,000U. Each urokinase delivery was followed by in travenous low molecular weight Dextran, 500ml / day, and Ginaton 87 5 mg / day, for 10 days. The treatment also included anterior chamber paracentesis, ocular massage, oral acetazolamide, sublingual isosorbide dinitrate, and inhalation of carbogen ( 95% oxygen, 5% carbon dioxide ). Visual acuity and ocular findings were recorded before and after treatment. Duration of follow up ranged from 4 to 12 months. After first intravaneous urokinase, visual acuity was slightly improved in five of the 6 patients, and no change in one patient. All 6 patients showed markedly improved vision at discharge, with vision better than 0 05. At the final visit, visual acuity reached 0 1 in all the 6 patients, and in four patients visual acuity was improved to 0 2 or better, two patients had vision recovered even to 1 2 and 1 5, respectively. During treatment no serious complications were noticed. These results indicate that systemic treatment for acute central retinal artery occlusion with high dose urokinase could help reestablish retinal circulation and improve vision.
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To establish a model of experimental retinal detachment and reattachment, extracapsular lens extraction and vitrectomy were performed in 78 adult cats. After three weeks, a glass micropipette with a flat tip (diameter 150～200?m) was inserted between the neural retina and retinal pigment epithelium (RPE) monolayer. Retinal detachments were produced by subretinal injection of 0.25% solution of Healon through this micropipette. Twenty～four hours later, detached retinas were reattached by air-fluid exchange and subretinal fluid drainage with a glass micropipette. Then 30% perfluoropropane (C 3F 8) gas temponade was porfomed. Retinal detachment was successfully made in 93.6%(73/78), and 97.1%(33/34)of the detached retinas were successfully reattached. By light microscopy, histologic sections showed that seperated retina located between RPE cells and photoreceptors, and neural retina contacted to RPE cells closely in reattached retinas. In conclusion, by using micropuncture, we have established an animal model of retinal detachment and reattachment with minimum injury to the retina, and a high rate of retinal detachment and reattachment were obtained.
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To observe the morphological changes in photoreceptor after experimental retinal detachment in cats. Twenty eight cats were divided into experimental group and control group. Retinal detachment was produced by injecting 0 25% solution of Healon into the subretinal space with the aid of a micropipette. Histologic sections of retina were processed for light and electron microscopy at detachment intervals ranging from 0 5 days to 3 months. At 24 hours postdetachment, the outer segments were distended and disrupted, but the inner segments and photoreceptor cell bodies were only slightly affected. 3-14 days after detachment, the inner segments were affected at multiple sites, albeit to varying degrees. Some of them were vacuolizated at the tip, with mitochondria swollen and cristae fragmented. At the same time, the photoreceptor cell bodies often showed a distension of endoplasmic reticulum, deterioration of mitochondria, and the presence of multivesicular bodies. 1-3 months after detachment, large empty spaces in the outer nuclear layer and a progressive loss of cytoplasmic ground substance and organelles appeared in some photoreceptors as detachment duration lengthened. Necrosis of the inner segments and cell bodies were more marked in the more serious detachment than those in shallow ones. Degenerative changes occured in the photoreceptor very soon after experimental retinal detachment, and these changes were correlated with both the depth and duration of retinal detachment.