Complications of proliferative diabetic retinopathy have become the major indications of vitrectomy. The surgery, however, is not basically a causative therapy. The visual function after operation depends on the degree of retinal ischemia and damage induced. The surgery itself has a potential for severe complications. Therefore it is important to better understand the pathology and to master surgical strategy and techniques in order to improve surgical outcomes and reduce the surgical complications. (Chin J Ocul Fundus Dis,2007,231-233)
Objective To observe the expression of N-cadherin in streptozotocin (STZ)-induced diabetic Sprague-Dawley (SD) ratsprime;retinae. Methods Celiac injection with 65 mg/kg STZ was performed on 20 rats to set up the diabetic model, and celiac injection with the same volume citrate buffer was performed on other 20 SD rats as the control. Vascular permeability was detected by Evans blue method. The expression of N-cadherin in both normal and STZ-induced diabetic ratsprime;retinae and trypsinase-digested retinal microvessels were detected by immunohistochemistry method and Western blotting analysis. Results Retinal vascular permeability increased 68%, 91% and 125% 4, 8, and 12 weeks, respectively, after diabetic models was induced (Plt;0.005). In the control group, the expression of N-cadherin was detected in the outer and inner plexiform layer, inner nuclear layer，ganglion cell layer,internal limiting membrane and between retinal endothelial cells and pericytes. However, the expression of N-cadherin significantly decreased in STZ-induced diabetic rats retinae at the 12th week. The results of Western blotting analysis showed that the expression of N-cadherin obviously decreased as the diabetic retinopathy developed. Conclusion The decrease of expression of Ncadherin in the retinae of STZ-induced diabetic rats suggests that N-cadherin may participate in the development of diabetic retinopathy at the early stage. (Chin J Ocul Fundus Dis,2007,23:269-272)
Purpose To study the refractive state of silicone oil tamponade eyes. Methods To calculate the theoretical refractive state of eyes with silicone oil based on clinical visual optics and to perform retinoscopy on 48 silicone oil filled eyes with pars plana vitrectomy (PPV) and 45 ones with PPV plus lens ectomy with retinal reposition, and then study theoretical and experimental differences of diopter in silicone oil filled eyes. Results Postoperative diopter of the former increases (+6.26plusmn;1.20)D than preoperative diopter, while that of the latter is (+11.40plusmn;2.22)D. Conclusion Hyperopic changes are found in silicone oil tamponade eyes, and the experimental values are lower than the theoretical ones. This may be helpful in predicting the change of diopter of silicone oil tamponade eyes. (Chin J Ocul Fundus Dis, 2001,17:102-104)
Objective To investigate the molecular mechanism of apoptosis in cultured human retinal pigment epithelial (RPE) cells. Methods The growth media of confluency human RPE cells were replaced with a daunoblastinacontaining one at a dose of 180mu;g/L,and the cells were incubated for 12 hr at 37℃.After incubation with the drug,the medium was withdrawn,fresh medium was added and incubation was carried out for an additional 24 hr.Apoptosis was monitored by light microscopy,enzyme linked immunosorbent assay(ELISA)and terminal deoxynucleotidyl transferase mediated biotin-dUTP nick-end labelling(TUNEL)staining.The expression of bax and bcl-2 were evaluated by immuncoytochemical staining with anti-human bcl-2 and bax antibodies. Results After the RPE cells treated with daunoblastina,shrinkage of cytoplasm and nucleus was identified.The ratio of nucleus to cytoplasm was increased.TUNEL staining showed that many cells were positive staining.The amount of apoptotic cells was directly proportional to the drug dose.The integral optical desity values for expression of bax inereased by 22.0%(Plt;0.05), and that of bcl-2 did not change significantly(Pgt;0.05). Conclusions During human RPE cell apoptosis induced by daunoblastina,overexpression of bax or low bcl-2/bax ratio were demonstrated.The results suggest that bax and bcl-2 gene expression could play a role in regulation of RPE cell apoptosis. (Chin J Ocul Fundus Dis, 1999, 15: 153-156)
Objective To assess the effectiveness of transpupillary thermotherapy (TTT) for the treatment of central exudative chorioretinopathy. Methods Tweenty-nine eyes with central exudative chorioretinopathy were treated with Iris 810 nm diode laser TTT. The laser beam size was 1.0, 2.0 or 3.0 mm with power settings between 80-300 mW and treatment time 60 sec. The follow up periods were wihzin 4-40 weeks. The therapeutic effect was accessed by visual acuity examination,dinect ophthalmoscopy and fluorescein or indocyanine green angiography. Results The visual acuity improved in 8 eyes (28%), remained no change in 19 eyes (65%) and decreased in 2 eyes (7%). Choroidal neovascularization were closed in 12 eyes in fundus angiography. The symptoms alleviated in 10 patients. Conclusion Transpupillary thermotherapy is a potential treatment for the central exudative chorioretinopathy. (Chin J Ocul Fundus Dis, 2002, 18: 184-186)
Objective To investigate the effects of transformin growth factor-beta (TGF-beta;) and interferon-gamma(IFN-gamma;)on collagen synthesis in human retinal pigment epithelial cells(RPE)． Methods TGF-beta;(0.01～10 ng/ml),recombinant IFN-gamma;(100～10000 Ｕ/ml)or a combination of two were added to cultures of RPE and collagen synthesis of the cells were measured by3 H-proline incorporation assay,indirect immunofluorescence staining and dot-blot hybridization. Results TGF-beta; at 10 ng/ml increased cell uptake of 3 H-proline to 130．87% of controls．It intensified Type IV,I and Ⅲ collagen fluorescent staining as well as mRNA expression．IFN-gamma; at 10000 Ｕ/ml caused 54．72% inhibition of 3 H-proline uptake by RPE,and decreased TypeⅣ collagen fluorescent staining as well as mRNA expression of Type Ⅳ,I and Ⅲ collagens. Conclusion TGF-beta; and IFN-gamma; stimulated and inhibited collagen synthesis of human RPE,respectively．The combination of two had antagonistic effects．IFN-gamma; can be used for inhibition of collagen synthesis of RPE. (Chin J Ocul Fundus Dis, 1999, 15: 245-248)
Purpose To investigate the expression of intercellular adhesion molecules ICAM-1 and Mac-1，in epiretinal membanes (ERM) of eyes wi th proliferative vitreoretinopathy (PVR)． Methods Twenty epiretinal membranes were obtained from eyes undergone vitrectomy for retinal detachment complicated with PVR and observed by immunohistochemical examination． Results Expressions of ICMA-1 and Mac-1 were observed in 18 and 15 membranes respectively．Expression of both adhesion molecules in 12 membranes． Conclusion The findings indicate that adhesion molecules might be involved in the development of PVR． (Chin J Ocul Fundus Dis，2000，16：71-138)
Objective To investigate the survivability of ret inal ganglion cells (RGC) after optic nerve crush with intraocular injection of schwann cells(SC) derived neurotrophic (SCNA) in vivo． Methods Schwann cells of 3～5 day newborn mice were cultured,conditioned media without serum was collected,ultraspeed centrifugalized,and frozen-dry.SD rats were divided into normal contrl,crush control,medium treatment and SCNA treatment groups,and 20 eyes in every group.RGC of adult rats were labelled with flu orogold.Seven days later,the optic nerve was intraorbitally crushed and SCNA was injected into the vitreous on the 5th,7th,21th and 28th day after crush,the number of RGC were counted respectively. Results The densities of RGC began to decrease on the 7th day after injury,the number of RGC was 70.2% and 40.5% of normal controls on the 14th and 28th day,respectively .In the group with SCNA injection,RGC densities decreased on the 7th day,but RGC densities were much higher then that of controls on the 14th,21th,and 28th day after injury (Plt;0.01). Conclusions SCNA administered intraocularly at the time of crush of optic nerve can protect RGC from injury and death of the cells. (Chin J Ocul Fundus Dis，2000，16：1-70)
Purpose To evaluate the efficacy of vitreous surgery for treatment of fundus damages caused by ocular blunt trauma. Methods Clinical records were reviewed retrospectively for a series of consecutive 101 patients (105 eyes) with fundus damages caused by ocular blunt trauma underwent vitreous surgery from October 1992 to March 1998． Results Based on clinical examination and findings during surgery,all cases were divided into 4 subgroups:vitreous hemorrhage(VH)in 23 yes,VH with retinochoroidal rupture or optic damage in 25 eyes,traumatic retinal detachment in 46 eyes,and retinal giant tear in 11 eyes.Vision acuity improvement achieved in 77 eyes(73.3%)and of them 69 eyes(65．7%)had 0.02～0．6with 38 eyes(55．0%)better than 0．1.Two eye s with no light perception obtained better than 0.1． Visual acuity remained unchanged in 26 eyes(24.8%)and 2 eyes(1.9%)became worse after operation．The retina reattached in 54 eyes(94.7%). Conclusion Severe ocular blunt trauma may cause visual impairment and various fundus damages.Appropriate vitreous surgery can salvage most eyes with those injuries. (Chin J Ocul Fundus Dis,1999,15:100-102)