Retinal neovascularization is a complicated pathophysiological process as a result of imbalance between angiogenic and anti-angiogenic factors. Correct understanding of the signaling pathways,exploring the critical factors involved in retinal angiogenesis, looking for new strategies by reconstructing the new vessels are helpful for knowing the mechanism of the occurrence and development of reitnal neovascularization, which would be good for preventing and treating retinal neovascularization diseases.

Objective To cultivate human retinal capillary endothelial cells (HRECs) and establish two-dimensional model of human retinal vessels in vitro. Methods In a fibronectin-coated raising pound, HRECs were cultured by non-serum human-endothelial-cells substrate and two-dimensional model of human retinal vessels was established. Horseradish peroxidase was used to detect the permeability. Some of the vascular models were cultivated with 5 ng/ml vascular endothelial growth factor (VEGF), whose changes of permeability was compared with which of the models without cultivation with VEGF. The effect of VEGF on vascular permeability was observed. Results Meshy vascular structure came into being due to the confluent HRECs after 2 to 4 days. Comparatively complete two-dimensional vascular model after about 6 days. VEGF increased vascular permeability and promoted the formation of blood vessels. Conclusion HRECs can be cultivated successfully with human-endothelial-cells substrate; standard retinal two-dimensional vascular model in vitro can be established by using cellular raising pound and non-serum human-endothelial-cells substrate.

Objective To observe the ultrastructural characteristics of human retinal progenitor cells cultured in vitro. Methods Six 5-month-old human fetuses(12 eyes)without eye diseases were selected. Retinal progenitor cells from the retina of one eye of each fetus were cultured in vitro,and observed by transmission electronic microscopy(TEM); while those from the other eye were directly observed by TEM. Results Abundant heterochromatin were found in the karyon of 5-month embryonic retinal neuroepithelial cells,and the figure of the karyons was irregular.A few scattered initial cells were seen in retinal neuroepithelial layer with large karyon,smooth surface,abundant euchromatin,and distinct nucleolus.The human retinal progenitor cells cultured in vitro had the same ultrastructural characteristics as the initial cells:with huge karyon which almost occupied the whole cell,little cytoplasm,distint nucleolus,abundant euchromatin,and little heterochromatin.The cells clung to each other in the neural globoid cell mass.The size of the outer cells was large,and karyokinesis could be found. Conclusion The cultured human retinal progenitor cells are provided with the same ultrastructure characteristics as the initial cells.

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, intraocular laser coagulation, air-fluid exchange and tamponiding of C 3F 8 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 complications 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 found. 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.

Objective To observe the long-term effect of suramin on the inhibition of proliferation of human retinal pigment epithelial (RPE) cells in vitro. Methods RPE cells grown in 9 pieces of 96-well plate (12 wells each plate) were divided into experimental and control group, with 6 wells in each group. The concentration of 0.1 ml RPE cells in each well is 5?104 cells/ml. After the change of the medium, RPE cells were treated with suramin (250 ?g/ml) in experimental group while treated with nothing in the control group. The medium of the 2 groups were changed to the normal medium after 4 days. At the 1~st , 2~nd , and 4~th day after the addition of suramin and at the 1~st , 2~nd , 3~rd , 5~th , 6~th , 7~th , 9~th , 11~th and 13~th day after removing suramin, 1 plate was randomly selected to stop culturing, and the proliferation of RPE cells were detected by methyl thiazolyl tetrazolium (MTT) assay. Results Under reversed microscope, RPE cells in control group were fused completely at the 7~th day after inoculation. The extracellular space of RPE cells in experimental groups was larger than that in the control group, and remained unfused at the 13~th day after inoculation. The inhibitory rate of proliferation of RPE cells at the first day after treated with suramin was 14.85% and increased to the highest 25.79% at the 4~th day. The first day after the suramin-containing media was removed, the inhibitory rate decreased to 12.35%, and then raised gradually to over 20% at the 3~rd to 5~th day. Finally, the rate drop to 14.71%. Conclusion Suramin has the long-term effect on the inhibition of RPE cells induced by serum, especially the inhibitive effect after the remove of suramin, which indicates the specific double-peak inhibition during the whole process.

Purpose To determine the effect of exogenous interleukin 1? (IL 1?) on the retina and its vasculature and VEGF expression in SD rats. Methods IL 1? 2.0 ng (20 ?l) were injected into the vitreous of 8 left eyes of 8 SD rats while steriled PBS were injected into 8 right contralateral eyes of the same rats as control. All eyes were assessed by direct ophthalmoscopy every day and enucleated on the 7 th postoperative day. Histological examination (hematoxylin eosin staining) and immunohistochemical staining with antibody against VEGF antigen were performed, and sections were observed and photographed under light microscopy. Results ①All 8 IL 1? injected eyes developed epiretinal membranes and extraretinal neovascularization on the 3 rd postoperative days while none of the 8 control eyes exhibited any abnormal retinal vascular changes and they were confirmed by HE staining;②Immunostaining identified VEGF express mainly in the inner layer of vessel walls, the epiretinal membranes, the neuroganglional layer and the photoreceptor layer of retina, while the control eyes showed only weak positive staining in the photoreceptor layer. Conclusions IL 1? is capable of inducing vitreo retinal neovascularization,and increasing the expression of VEGF in the retina and epiretinal membranes.

Objective To investigate the histopathologic characteristic 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 contained epithelia, 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.

Objective To determine the expression of the growth factors and the receptors related to angiogenesis in the intraocular tissues incarcerating in the sclerotomy sites. Methods Ten specimens from prolapsing intraocular tissues in sclerotomy sites during vitrectomy were obtained and serially sectioned in cryostate and were stained with a group of polyclonal antibodies against vascular endothelial growth factor(VEGF), basic fibroblast growth factor (bFGF), platelet derived growth factor A(PDGF A) and transforming growth factor ? 1(TGF ? 1) as well as their receptors by using a streptavidin peroxidase system. Results The tissues prolapsed from the sclerotomy sites were identified as retina(3 cases), vitreous tissues(3 cases), degenerated red blood cell components(2 cases), ciliary body(one case) and fibrous tissue(one case). All specimens expressed VEGF and bFGF as well as their receptors. PDGF A, TGF ?1 and their receptors expressed in the most of specimens. The positive cells included retinal cells, ciliary non pigmented epithelial cells and pigmented epithelial cells, fibrous cells and the cells in vitreous. Conclusions The intraocular tissues incarcerated in the sclerotomy entries express the growth factors and receptors related to angiogenesis. This might be one of the potential factors of developing anterior proliferative vitreoretinopathy.

Recent years have witnessed tremendous progress in vitreoretinal surgery.The treatment of vitreoretinal diseases has increased enormously and its related indications expanded widely with the contribution of the emerging novel technologies,methods,equipment and new ideas.Attaching importance to minimally invasive surgery,application of auxiliary drugs,development of improved equipment and surgical technique were the main features. Further basic and clinical research is necessary to promote innovation and development of vitreoretinal surgery in China to keep pace with and surpass advanced technology.

Objective To observe the adhension and stracking of leukocyte in the capillary vessels, and investigate the relationship between leukocyte and microvascular morphologic changes in retinal microvessels of rats with early diabetes. Methods A total of 90 healthy adult male Wistar rats were randomly divided into control and diabetes (induced by Streptozotocin, STZ) groups with 45 rats in each group. The rats in the diabetic group were further divided into 3, 7, and 14 days groups with 5 rats in each group, and 30, 90, and 180 days groups with 10 rats in each group. The right eyes of rats in each group were prepared for retinal digest preparations. The expression of leukocyte common antigen (CD45) was detected by immunohistochemical staining. Results Few CD45 positive cells in the retinal capillaries were seen in the control group. The expression of CD45 was significantly increased in the retinal capillaries 3 days after diabetes induction, and reached a peak at the 14th day. Morphological changes including capillary telangiectasia, atresia, and irregularity of capillary caliber were found in the retinal capillaries of rats 90 days after diabetes induction. The changes were aggravated 180 days after diabetes induction. Conclusion Leukocyte adhesion occurs in the early stage of diabetic retinopathy (DR), and is the beginning of the microvascular pathological changes. Leukocyte adhesion may play an important role in the occurrence and development of DR as the foundation of microvascular morphological changes.