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 ）
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.
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)
Purpose To investigate the effects of human vitreous fluid on proliferation of cultured human retinal pigment epithelial (RPE) cells and vascular endothelial cell lines(VEC304). Methods Human RPE cells and VEC304 were cultured and treated in different human vitreous-conditioned medium (VCM) with or without serum, vitreous volume concentrations of VCM were 1∶8, 1∶4 and 1∶2. Cells proliferation was assayed by tetrazolium (MTT) colorimetry at the 2nd, 4th and 6th day respectively. Results In the presence of serum, 1∶4, 1∶2 VCM had a significantly stimulative effect on RPE cells proliferation compared with control group at the 2nd, 4th, and 6th day retrospectively (P＜0.01), but exerted a bly inhibitory effect on VEC304 proliferation compared with control group at the 2nd, 4th, and 6th day retrospectively (Plt;0.05). In the absence of serum, only 1∶2 VCM had a stimulative effect on RPE cells growth compared with control group at the 2nd day (P＜0.05) and obviously at the 4th and 6th day respectively (P＜0.01). Conclusion Human vitreous fluid influences human RPE cells and VEC304 growth in vitro. This result suggests that vitreous may play different role in proliferative vitreoretinopathy and intraocular neovascular disease. (Chin J Ocul Fundus Dis, 2002, 18: 140-142)
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 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 investigate the effect of tetrandrine (Tet) on experimental choroidal neovascularization and the effect of Tet on retinal structure and function. Methods Choroidal neovascularization was induced in 20 Brown Norway (BN) rats (40 eyes) by diode laser (wavelength: 810 nm; exposal time: 0.1 second; facular diameter:100 mu;m; energy: 120 mW), and the rats were divided randomly into experimental and control group with 10 rats (20 eyes) in each group. In experimental group, 0.05 ml Tet with the concentration of 3.21 mu;mol/L was injected intravitreously 0 and 3 days after laser photocoagulation; in the control group, the rats underwent an intravitreous injection with the same volume of sodium chloride solution. The incidence of CNV was evaluated by fundus fluorescein angiography (FFA) 14 days after laser photocoagulation. Five right eyes of another Five healthy BN rats underwent intravitreous injection with 0.05 ml Tet with the concentration of 3.21 mu;mol/L, and an intravitreous injection with the same volume of sodium chloride solution was performed on the left eyes. Before injection, 1 hour, and 1 day after the first injection, and 1 hour, 1 day, 7 days, 14 days after e second injection the electroretinography (ERG) was performed on these 5 rats; 14 days after the second injection, the retinae were examined by light microscopy and transmission electron microscopy. Results The incidence of CNV was 23.26% in experimental group，which was obviously lower than that in the control group (63.33%) (Plt;0.01). The ratio of amplitude of b wave of ERG in the rats undergone intravitreous injection with 3.21 mg/ml Tet didnprime;t differ much from which before the injection (Pgt;0.05). There were no structural changes of retinal tissues examined by light and electron microscopy. Conclusion Tet may inhibit choroidal neovascularization in rats; there isnprime;t any significant toxic effect of intravitreous injection with Tet on retina at the dosage of 3.21 mu;mol/L. (Chin J Ocul Fundus Dis, 2006, 22: 242-244)
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)
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)