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)
Objective To evaluate the indications, effectiveness and complications of vitreoretinal surgery using the 25G transconjunctival sutureless vitrectomy system (TSV25G) under the topical anesthesia. Methods The clinical and follow-up data of 22 eyes of 22 patients undergone vitreo-retinal surgery using TSV25G under the topical anesthesia were retrospectively analyzed. All of the patients were monocular sickened, including idiopathic macular hole in 10 eyes, idiopathic macular pucker in 6, vitreoretinal traction syndrome in 4, and vitreous hemorrhage associated with branch retinal vein occlusion in 2. Peeling of epiretinal membrane and/or internal limiting membrane, intra ocular laser coagulation, air-fluid exchange and tamponiding of C3F8 were performed according to the condition of diseases. The postoperative follow-up was 1-11 months, with the mean duration of 6.4 months. The effect of analgesia, cooperation with the patients, operative effect and complications in and after the surgery were observed. Results The operations finished successfully in all of the eyes under the topical anesthesia. The operation duration ranged from 20 to 25 minutes with average of 22 minutes. The patients cooperated with the doctor well without any discomfort. Two days after the surgery, edema of the wounded conjunctiva was found, and recovered 7 days later. A light pigment dot on the surface of the sclera could be seen at the first month. The complic ations included transient increasing of intraocular pressure in 2 eyes, feather-like opacity of lens in 5 eyes, vitreous hemorrhage in 1 eye, and air-bleb under conjunctiva in 2 eyes. No other complications related with the cut were fo und. The macular hole closed in 9 eyes with idiopathic macular hole, and the other 1 had the smaller but not closed hole. Idiopathic macular pucker, vitreoretinal traction syndrome, and vitreous hemorrhage associated with branch retinal vein occlusion were cured successfully. Conclusions Vitreoretinal surgery using the TSV25G under the topical anesthesia has many advantages such as simple procedure, short operation time, micro-invasion, less complications and rapid revovery, and mainly serves simple manipulation in some simple diseases such as idiopathic macular hole, vitreo-retinal traction syndrome, and simple hemorrhage. (Chin J Ocul Fundus Dis，2004，20：133-136)
Objective To review the distribution and shifting trends of cultured bacteria from the aqueous humor and the vitreous body. Methods A retrospective analysis on distribution of Gram′s stain, the distribution and change of isolates was performed in 522 specimens (aqueous humor,261 and vitreous body,261) of patients with suspected endophthalmitis during a 10-year period (1989-1998). Results The positive cultures were 119 (aqueous humor,44 and vitreous body,75) of 522 specimens. The average positive rate was 22.8%. Gram-positive cocci constituting 45.4%(54) of total isolates followed by Gram-negative bacilli,34.5%(41);Gram-positive bacilli, 20.2%(24). In the positive bacterial cultures, enterobacteriaceae was the most common isolate, 18.5%, and the next was micrococcus, 16.0%; coagulase-negative staphylococcus,12.6%; and pseudomonas,10.9%.Comparing the data from 1989 through 1993 with the data from 1994 through 1998, the frequency of Gram-positive cocci had no significant change, while the frequency of Gram-positive bacilli was decreased and the percentage of Gram′s-negative bacilli was increased. Conclusions Gram-positive cocci and Gram-negative bacilli are the predominant pathogens of bacterial endophthalmitis. The percentage of Gram′s-negative bacilli has increased for 5 years. It is very important to comprehend the distribution and shifting trends of these pathogenic bacteria for diagnosis, prevention and treatment of bacterial endophthalmitis. (Chin J Ocul Fundus Dis, 2002, 18: 104-105)
Objective To investigate the effects and complications of the vitrectomy for Eales′ disease with vitreous hemorrhage or traction retinal detachment. Methods Seventy-seven eyes of 69 cases undergoing vitrectomy for Eales′ disease with vitreous hemorrhage or traction retinal detachment were analyzed retrospectively. Results (1) The postoperative visual acuity was enhanced significantly. (2) Complications during the operation in 11 eyes (14.3%): iatrogenic retinal break in 7 eyes, bleeding in 3 eyes and lens damage in 1 eye. (3) Postoperative complications in 20 eyes (26.0%): rebleeding in 14 eyes, elevated IOP in 6 eyes, retinal detachment in 5 eyes, hyphema in 2 eyes, and exudative membrane in anterior chamber in 1 eye. (4) The main long-term complication was cataract formation (9 eyes) and macular disorder (6 eyes). Conclusion Vitrectomy is an effective method to treat Eales′ disease with vitreous hemorrhage or traction retinal detachment. (Chin J Ocul Fundus Dis, 2002, 18: 215-217)
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 investigate the risk factors of postoperative vitreous hemorrhage after minimal vitrectomy without endotamponade for proliferative diabetic retinopathy (PDR).MethodsFrom June 2015 to June 2017, 103 eyes of 103 patients with PDR diagnosed and underwent minimalvitrectomy in Henan Provincial People's Hospital were enrolled in the study. There were 58 males and 45 females, with the average age of 58.37±10.14 years and diabetes duration of 8.7±7.2 years. Baseline systemic parameters including sex, age, diabetes duration, hypertension, HbA1c, creatinine, whether received anticoagulants, ocular parameters including whether combined with vitreous hemorrhage, whether finished panretinal photocoagulation (PRP), whether received treatment of anti-VEGF, whether combined with iris neovascularization (NVI), lens status preoperatively, whether hypotony postoperatively and intraoperative parameters including whether disc neovascularization (NVD) bleeding, whether fibrovascular membrane (FVM) residual, laser points, whether combined with cataract phacoemulsification were identified by multivariate logistic regression analysis.ResultsTwenty-nine of 103 eyes (28.15%) developed PVH in 1 day to 6 months after surgery, with self absorption of 18 eyes and reoperation of 11 eyes. Univariate analysis showed there were significant differences in age (t=2.124, P=0.036), anti-VEGF(χ2=7.105, P=0.008), NVD bleeding (χ2=10.158, P=0.001) and FVM residual(χ2=8.445, P=0.004) between patients with and without postoperative vitreous hemorrhage. Sex (χ2=0.021, P=0.884), diabetes duration (t=0.87, P=0.386), hypertension (χ2=2.004, P=0.157), HbA1c (t=1.211, P=0.229), creatinine (t=0.851, P=0.397), preoperative oral anticoagulants (χ2=0.985, P=0.321), preoperative vitreous hemorrhage (χ2=0.369, P=0.544), PRP (χ2=1.122, P=0.727), NVI (χ2=2.635, P=0.105), lens status (χ2=0.172, P=0.679), hypotony postoperatively (χ2=1.503, P=0.220), laser points (χ2=1.391, P=0.238) and combined phacoemulsification surgery (χ2=0.458, P=0.499) were not associated with PVH. Multivariate logistic regression analysis revealed the more PVH appeared in younger (OR=1.065, P=0.009) and NVD bleeding (OR=6.048, P=0.001) patients.ConclusionYounger age and NVD bleeding are the important risk factors for PVH after minimal vitrectomy without endotamponade in PDR.
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)
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 investigate the histopathologic charact eristic of the vitreous herniation out of sclerotomy site during vitrectomy. Methods Twenty specimens of tissues herniated at vitrectomy site were collected. The paraffin sections or fresh smears were stained with hematoxylineosin and examined under light microscope. The specimens were collected from the affected eyes with rhegmatogenous retinal detachment (9 cases), traumatic retinal detachment (1 case), miscellaneous vitreous hemorrhage (6 cases) and intraocular foreign body (4 cases). Results The herniated tissues were found to be retina in 4 cases, ciliary tissue in 1 case, retina and ciliary tissue in 1 case, uvea in 1 case, and hyaloid tissue in 13 cases. Conclusion There were not only vitreous, ciliary epithelial cells and pigment containe depithelia, but also ciliary body, retina and uvea in the prolapsed tissues of sclerotomy site, which might be related to the occurence of some clinical complications. (Chin J Ocul Fundus Dis,2001,17:99-101)
ObjectiveTo observe the expression of S100A8 in plasma exosomes, microvesicles (MV), plasma and vitreous in patients with diabetic retinopathy (DR), and verify it in a diabetic rat model, and to preliminarily explore its role in the occurrence and development of DR.MethodsA case-control study. From September 2018 to December 2019, a total of 73 patients with type 2 diabetes, hospitalized patients undergoing vitrectomy, and healthy physical examinations in the Tianjin Medical University Eye Hospital were included in the study. Among them, plasma were collected from 32 patients and vitreous fluid were collected from 41 patients, which were divided into plasma sample research cohort and vitreous sample research cohort. The subjects were divided into simple diabetes group (DM group), non-proliferative DR group (NPDR group) and proliferative DR group (PDR group) without fundus changes; healthy subjects were regarded as normal control group (NC group). In the study cohort of vitreous samples, the control group was the vitreous humor of patients with epimacular membrane or macular hole. Plasma exosomes and microvesicles (MVs) were separated using ultracentrifugation. Transmission electron microscopy, nanometer particle size analyzer and Western blot (WB) were used to characterize exosomes and MVs. The mass concentration of S100A8 was determined by enzyme-linked immunosorbent assay. Eighteen healthy male Brown Norway rats were divided into normal control group and diabetic group with 9 rats in each group by random number table method. The rats of diabetes group were induced by streptozotocin to establish diabetic model. Five months after modeling, immunohistochemical staining and WB were used to detect the expression of S100A8 in the retina of rats in the normal control group and the diabetes group. t test was used for the comparison of measurement data between the two groups. Single-factor analysis of variance were used for the comparison of multiple groups of measurement data.parison of measurement data between the two groups. Single-factor analysis of variance were used for the comparison of multiple groups of measurement data.ResultsExosomes and MVs with their own characteristics were successfully separated from plasma. The concentrations of plasma exosomes and vitreous S100A8 in the PDR group were higher than those in the NPDR group, DM group, NC group, and the difference was statistically significant (P=0.039, 0.020, 0.002, 0.002, P＜0.000,＜0.000). In the plasma sample cohort study, It was not statistically significant that the overall comparison of the S100A8 mass concentrations of plasma and plasma MV in the four groups of subjects (F=0.283, 0.015; P=0.836, 0.996). Immunohistochemical staining showed that retinal ganglion cells, bipolar cells, cone rod cells and vascular endothelial cells in the diabetic group all expressed S100A8 protein. Compared with the normal control group, the expression level of S100A8 in the retina of the diabetic group increased, and the difference was statistically significant (t=8.028, P=0.001).ConclusionsThe level of S100A8 protein in circulating exosomes increases significantly with the severity of DR in patients with type 2 diabetes. S100A8 may be an influential factor in the inflammatory environment of DR and a potential anti-inflammatory therapeutic target.