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 ）
Purpose To explore the role of scanning laser tomography in the assessment of macular hole surgery. Methods Fifteen eyes of 14 patients with macular holes underwent scanning of their affected macular area using the Heidelberg retina tomograph (HRT). The significance of topographic changes postoperatively were determined in eleven eyes which received vitrectomy surgery. The scan field was set at 15°of the retina and the depth was set to 1.5 mm or 2.0 mm. All the measurements were taken for 3 times and the average value of the 3 measurements was used. Results The average hole area was (0.499±0.34) mm 2 and the maximal depth of the hole was (0.284±0.11) mm. Topographic difference analysis of the eleven eyes showed a significant reduction in the height of the retina after vitrectomy. The maximal depth of the hole was (0.063±0.04) mm postoperatively. Conclusion Scanning laser tomography provides an objective evaluation of the anatomic outcome of the macular hole surgery. (Chin J Ocul Fundus Dis, 2002, 18: 125-127)
ObjectiveTo analyse the effect of vitrectomy in diagnosing and treating endogenous endophthalmitis. MethodsThe effects of treatment, prognosis and the final follow-up visual acuity of 22 patients (30 eyes) with endogenous endophthalmitis diagnosed in our hospital from Jan 2000 to Dec 2003 were retrospectively reviewed.ResultsIn 21 patients who underwent blood or vitreous body smear and culture, 18 (86%) had a positive result, including bacteria in 6, fungi in 11, and mixed infection in 1. In 16 patients who had complete follow-up data, successful vitrectomy were performed on 13 (81.3%) including 6 with functional success.ConclusionVitrectomy may improve the positive rate of culture and vision prognosis in patients with endogenous endophthalmitis.(Chin J Ocul Fundus Dis, 2005,21:142-144)
Objective To investigate the effect of retinectomy 360° for severe ocular rupture and evaluate the related factors associated w ith prognosis. Methods We retrospectively analyzed 28 consecutive patients (28 eyes), 18 men and 10 women, with severe ocular rupture admitted to the Chinese PLA General Hospital between January 1999 and October 2002. The patient′s ages ragned from 16 to 58 years, mean 29 years. According to the internation standardized classification of ocular trauma, the injuries located in zone I in 5 eyes, zone I-II in 8 eyes，zone II in 3 eyes, zone II-IIIⅢ in 5 eyes, zone III in 7 eyes, zone II in 3 eyes, zone II-III in 5 eyes and zone III in 7 eyes. The presenting visual acuity was in grade 4 (0.02 to light perception) in 19 eyes, and grade 5 in 9 eyes. In 28 patients, 13 had the total absence of iris and lens, 10 had iris deletion more than 1/2, and 15 had lens opacity or rupture. Ultrasound biomicroscopy and B-scan revealed ciliochoroidal detachment in 17 eyes. The B-scan revealed vitreous hemorrhage and retinal detachment in all paitents. The intraocular pressure was from 5 to 11 mm Hg in all patients. The therappeutic operative procedures which were performed by one surgeon in all of the affected eyes included standard 3-port pars plana vitrectomy with scleral encircling buckle, endophotocoagulation and tamponading with silicone oil in all patients; lensectomy in 15 eyes; 360° retinotomy and retinectomy at anterior equator in 16 patients, and posterior equator in 12 eyes.Results During the operation, all patients were confirmed with vitreous hemorrhage and retinal detachment, including hemorrhagic ciliary body detachment in 9 eyes, suprachoroidal hemorrha ge in 12 eyes, retinal twisting like morning glory in 11 eyes, and retinal incarceration in 17 eyes. Postoperative follow-up In 26 eyes who were followed up postoperatively from 6 months to 46 months, retinal reattachment was found in 20 patients (76.9%) in whom the retina of 3 was reattached after revitrectomy and the silicone oil of 8 was removed at the fourth month after operation. In 20 eyes with reattached retina, 14 (70.0%) had corrected visual acuity of 0.02 or more, including 7 (35.0%) had 0.05 or more, 3 had 0.1 or mor e, and 1 had the best visual acuity of 0.3.Conclusion Retine ctomy may improve the prognosis of severe ocular rupture and save the visual fun ction of some patients.(Chin J Ocul Fundus Dis，2003，19：333-404)
Objective To observe the efficacy of vitreoretinal surgery in the treatment of early traumatized eyes with no light perception. Methods We performed vitreoretinal surgery on 17 eyes of early traumatized eyes with no light perception.The patients were followed up for 2～14 months. Results Retinal reattachment was achieved in 11 eyes after srugery.8 eyes got visual acuity better than light perception postoperatively.Visual acuities of 5 eyes were better than 0.05 and the best one reached to 0.2. Conclusion Timely vitreoretinal surgery is valuable to the early traumatized eyes with no light perception.Retinal reattachment is the most important thing for the treatment of this kind of cases. (Chin J Ocul Fundus Dis，2000，16：213-284)
Objective To describe cultured human retinal pigment epithelial (RPE) cells transdifferentiation and investigate the effects of human vitreous fluid on the morphologic and cytoskeleton changes of RPE cells in vitro. Methods Cytoskeleton characteristics in the 2nd, 5th, 8th passage of RPE cells in normal culture, which included cytokeratin 18 (CK18) and α-smooth muscle actin (α-SMA) were analyzed by Western blot. RPE cells were cultured in human vitreous-conditioned medium (VCM) at the concentration of 1∶4 for 6 days, morphologic changes were examined by light and electron microscopy, and cytoskeleton characteristics were analyzed by imunocytochemistry and Western blot. Results During culture in vitro, RPE cells lost epithelial characteristics and aquired fibroblast-like phenotype. The expression of CK18 was the highest at the 5th passage, and it decreased in the following passage, but α-SMA increased gradually. The morphologic transdifferentiation from epithelial to fibroblast-like cells of RPE was accelerated by VCM. Ultrastructural changes such as decreased microvilli and gradually increased rough endoplasmic reticulum and Golgi complex were found during the cultivation. CK18 produced by RPE cells decreased in VMC (P＜0.05), and α-SMA increased (P＜0.01). Conclusion Morphologic changes in epithelialmesenchymal transdifferenetiation of RPE cells are stimulated by VCM and accomplied by the shift of cytoskeleton proteins, The results imply that cells migration may be decreased and contraction may be enhanced in VCM. It may suggest that vitreous accelerates the pathogenesis of PVR and RPE cells play an important role. (Chin J Ocul Fundus Dis, 2002, 18: 289-292)
Objective To explore the correlation between retinal extracellular edema and vitreous contraction in rabbits. Methods Seventeen pigmented rabbit models with retinal vein occlusion (RVO)was set up by laser photocoagulation. Retinal vascularity area was pathologically examined 1 month later.The vitreous gellength under the gravity condition and the percentage of its weight in the rabbits with extraeellular edema was observed. The mechanisms were investigated by Western immunoblotting of type II collagen.Results Extracellular edema was found in 13 experimental eyes 1 month after the formation of RVO (76.5~) with contracted vitreous gel and released watery liquid, and the a component of type II collagen was cross-linked together to form high-molecular-weight components of 1] and 7, which weakened the stability of collagen net structure.Conclusions Vitreous contraction and retinal extracellular edemawere correlated. The main reason may be the cross-links of vitreous collagen that damages the stability of collagen structure. (Chin J Ocul Fundus Dis，2004，20：2-32)
ObjectiveTo investigate the relationship between the posterior vitreous detachment (PVD) and the diabetic macular edema (DME).MethodsA total of 169 eyes with DME which were diagnosed by funduscopy，fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) were retrospectively analysed. PVD and partial PVD were detected by OCT and biomicroscopy. The characterizations of OCT images of DME were analysed.ResultsIn 169 eyes, 156 (92.3%) had no PVD with the average thickness of fovea of 297 μm; 11 (6.5%) had complete PVD with the average thickness of fovea of 229 μm; 2 (1.2%) had partial PVD with the average thickness of fovea of 347 μm.ConclusionsOnly a few PVD were found in DME eyes, so traction of PVD may not be the main cause of DME. (Chin J Ocul Fundus Dis, 2003,19:341-343)
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 reveal the fibrillar network in vitreous and the effect of plasmin on this network.Methods 20 vitreous gels of freshly slaughtered pigs were divided into 2 groups, the gels in first group were digested by 3 Uplasmin (3 U/ml) at 37c for 24 hours respectively, the second group received the same PBS as control. After digestion, gels were fixed in neutral buffered formalin solution. Samples from vitreous base, cortex and the central region were observed by the technique of freeze etching electron microscopy.Results In vitreous collagen fibril network was in a three-dimensional array, collagen fibril density showed marked differences, central vitreous had the sparse fibril density, the cortex denser and the basal vitreous densest. After digestion by plasmin, the collagen fibrillar network was destructed.Conclusion Collagen fibrils in vitreous present spatial arrangement regularly, plasmin can lead to destruction of the fibrillar network.(Chin J Ocul Fundus Dis，2003，19：179-181)