OBJECTIVE:To evaluate the toxicity of retinoic acid in silicone oil to the retinal tissue. METHOD:Twelve New Zealand white rabbits(24 eyes)were divided into three grorps at random. Three days after gas-compression vitrectomy,24 eyes were unedrgone gas/silicone oil exchange. The silicone oil 0.5 ml was injected intravitreally in 4 eyes as controls ,and 5mu;g/ml retinoic acid silicone oil 0.5ml in 10 eyes and 10 mu;g/ml retinoic acid silicone oil 0.5 ml in 10 eyes respectively as 2 study groups. After intravitrea[ injections, all the eyes were examined by ophthalmoscopy on the 1st, 3rd, 7th, 14th, 21st and 28th day. The retinas of the enucleated eyes on the 28th day were then examined by light microscopy and transmission electrone microscopy. RESULT: No evidence of toxicity was found in retinas after intravitreal injections of silicone oil with 5 mu;g/ml or 10 mu;g/ml retinoic acid. CONCLUSION :There was no toxic effect on the retinas by using 5 mu;g/ml or 10 mu;g/ml retinoic acid in intravitreal silicone oil tamponade operation. （Chin J Ocul Fundus Dis,1997,13: 81-82）
ObjectiveTo compare the effects of intravitreal tamponade of C3F8 with silicon oil on postoperative vitreous hemorrhage and visual prognosis after vitrectomy for proliferative diabetic retinopathy (PDR). MethodsThe clinical data of 121 patients (127 eyes) who underwent primary vitrectomy due to PDR were analyzed retrospectively. All the patients were divided into two groups according to different intravitreal tamponade, including C3F8 tamponade group (53 patients with 56 eyes) and silicone oil tamponade group (68 patients with 71 eyes). There was no difference of gender (χ2=0.956), age (t=1.122), duratiion of diabetes (t=0.627), fasting blood glucose (t=1.049), systolic pressure (t=1.056), diastolic pressure (t=0.517), history of hypertension (χ2=0.356), nephropathy (χ2=1.242), preoperative laser photocoagulation (χ2=1.225) and All the patients underwent three port pars plana vitrectomy. The mean follow-up was 2 years ranging from 6 months to 4 years. And then the incidence and onset time of postoperative vitreous hemorrhage and postoperative BCVA of the two groups were compared. ResultsPostoperative vitreous hemorrhage occurred in 14 of 56 eyes (25.00%) in C3F8 tamponade group. The average onset time of postoperative vitreous hemorrhage were (64.64±59.09) days ranging from 7-225 days and mostly were within 30-60 days (35.71%, 5/14). Postoperative vitreous hemorrhage also occurred in 7 of 71 eyes (9.89%) of silicone oil tamponade group after silicone oil removal with an average onset time of (25.29±20.46) days ranging from 3-65 days and were mostly within 15-30 days (42.86%, 3/7). There was a significant difference in the incidence of postoperative vitreous hemorrhage between the two groups (χ2=5.200, P<0.05). BCVA of the two groups was improved significantly after operation (Z=2.472, 3.114; P<0.05). Postoperative BCVA of silicone oil tamponade group was poorer than C3F8 tamponade group (Z=1.968, P<0.05). ConclusionBoth C3F8 and silicone oil tamponade can improve the visual acuity after vitrectomy for PDR. Compared with C3F8, silicone oil tamponade had lower incidence and late onset of postoperative vitreous hemorrhage after vitrectomy for PDR.
In order to improve the therapeutic effect of non-neural tissue in bridging the peripheral nerve defect and increase the blood supply of the implant, the silicone tube was chosen to bridge the gap, and the vessel bundle was inserted into the tube. The procedures were performed as following: resected the pseudoneuroma and enveloped the proximal and the distal ends in a silicone tube, and then sutured the epineurium and the tube wall with 7/0 stitch. In patients, eleven cases with fifteen nerves were treated, including seven median nerves, five ulnar nerves and three radial nerves. The lengths of the nerve defects were within 3 cm in 13 nerves and 3 cm-5 cm in 2 nerves. They were followed up from one to five years and the result was excellent (M4S4) in 8 nerves, good (M3S3) in 3 and poor (M1S1) in 2. It was discussed that the indication for the procedure should be included: the nerve defect could not be sutured directly, and the patient would not agree to use his own nerve for graft.
PURPOSE:To evaluate the ability Of retinoic acid(RA) in silicon oil(SiO)to inhibit the proliferation of injected intraocular fibroblast cells. METHODS:Thirty New Zealand white rabbits (58 eyes)were divided into three groups. In control group ,only SiO(10 eyes)or BSS(10 eyes)were injected intravitreally and 5mu;g/ml (18 eyes)or 10mu;g/ml (20 eyes)RA in SiO were injected into other lwo groups respectively. Three days after gas-compression vitrectomy, 2 times;105 fibroblasts and Sio(0.5ml)or BSS(0.5ml)were injected in all eyes sequentially.The morbidity of tractional retinal detachment (TRD) were observed by ophthalmoscope until 4 weeks. RESULTS:After 4 weeks,in control ,5mu;g/ml RA in SiO and 10mu;g/ml RA in SiO group,80. 00%,44.44%,and 30.00% eyes developed TRD respectively. Significant statistical differences were found between the control group and the two treated groups (P＜0.05). CONCLUSIONS:5mu;g/ml or 10mu;g/ml RA in SiO can inhibit the occurrence of TRD effectively. （Chin J Ocul Fundus Dis,1997,13:174-176）
Objective To evaluate the effect of vitreoretinal surgery with lens-sparing technique in treating the detachment with giant retinal tear(GRT) associated with proliferative vitreoretinopathy(PVR). Methods Thirty-one consecutive eyes with GRT unde rwent vitrectomy were analysed retrospectively. Operative techniques included peeling of pre-retinal membrane， injection of perfluorodecalin liquid， retinotomy and retinectomy，endolaser，and silicon oil or C2F6 gas tamponade. Lens-sparing vitrectomy was performed in 28 phakic eyes. Follow-up period ranged from 11 to 34 months. Results Anatomic retina l attachment was achieved intraoeratively in 29 eyes. In 16 eyes of 28 eyes with postoperative cataract formation,3 eyes underwent cataract surgery with or without intraocular lens implantation. The corrected final visual acuity ran ged from 0.4 to 0.01. Conclusion Most phakic eyes of retinal detachment with GRT PVR can be successfully operated on with an out come of improving the visual acuity by using techniques of lens-sparing vitrectomy, perfluorodecalin liquid and silcone oil tamponade. (Chin J Ocul Fundus Dis, 2001,17:93-95)
Objective To evaluate the effects of intraocular lenses (IOL) of silicone and polymethylmethacrylate (PMMA) on posterior capsule opacification (PCO). Methods We searched MEDLINE (1966 to 2003), EMBASE (1980 to 2003), Cochrane Central Register of Controlled Trials (Issue 1, 2003) and CBMdisc (1979 to 2003). Only randomized controlled trials (RCTs) were identified. Two reviewers independently assessed the quality of the included trial and extracted data. The following outcomes were assessed: PCO index, percentage of neodymium: YAG (Nd: YAG) laser posterior capsulotomy and visual acuity after cataract surgery. RevMan 4.2 was used for meta-analysis.Results Nine RCTs including 672 eyes were included. In patients with senile cataract, the results of meta-analysis suggested that silicone lens were better than PMMA lens on PCO index (the pooled SMD=－0.92, 95%CI －1.19 to －0.64) and percentage of Nd: YAG (the pooled OR 0.35, 95%CI 0.22 to 0.57) with a statistically significant difference, but there was no significant difference on visual acuity (the pooled OR 1.22, 95%CI 0.43 to 3.50) after cataract surgery between silicone lens and PMMA lens. However, in patients with uveitic cataract, the results of meta-analysis showed that PMMA lens were better than silicone lens in visual acuity (the pooled OR 0.38, 95%CI 0.15 to 0.91) after cataract surgery with a statistically significant difference, but there was no significant difference on PCO index (SMD 0.23, 95%CI －0.59 to 1.05) and percentage of Nd: YAG (the pooled OR 1.82, 95%CI 0.47 to 6.95) between silicone lens and PMMA lens. Conclusions Current evidence indicates that silicone lens are superior to PMMA lens in reducing PCO. Further trials with high quality on methodology are required.
Objective To observe the effect of preservation of an terior lens capsule on the incidence of complications associated with silicone oil. Methods Eighty-two patients(82 eyes)accepted trans pars plana vitrectomy combined with lensectomy,30 eyes with preservation of an terior lens capsule (PAC) and 52 eyes with no preservation of anterior capsule(N PAC)were observed.The incidence of complications was analysed to investigate whe ther PAC could reduce the complications associated with the usage of tamponade of silicone oil. Results The incidence was 50.0% in NP AC group,and 23.3% in PAC group(0.010lt; Plt; 0.025).There were secondary glaucoma(21.1%),band keratopathy(13.5%)and corneal decompensation(9.6%)in NPAC group,while there was none of them in PAC group. Conclusion Preservation of anterior lens capsule is an effective measure to reduce the complicaltons associated with the tamponade of silicone oil. (Chin J Ocul Fundus Dis, 2001,17:41-43)
Along with the wide application of silicone gel implants in augmentation mammaplasty, more complications appeared. The author reported 24 cases of complicationssince 1989, including one case of heamtoma, one case of infection, two cases of injury of the sensory nerves to the nipple, four cases of asymmetric breast (as ymmetry in position and size), three cases of deformed appearance, six cases of constracture of the fibrous coating membrane, one case of rupture of prosthesis,one case of sinus formation and three cases of abnormal milk secretion. The causes of the complications and their prevention were discussed.
ObjectiveTo observe the effect and complications of vitrectomy combined with intraocular silicon oil or C3F8 filling for proliferative diabetic retinopathy (PDR). MethodsEighty-six consecutive patients (101 eyes) with PDR-related vitreous hemorrhage who underwent primary standard three-port vitrectomy and intraocular tamponade of silicone oil or C3F8 were included in this retrospective study. They were divided into silicone oil group and C3F8 groups. There was no statistically significant difference between these two groups of patients for gender, age, duration of diabetes, fasting glucose, history of hypertension, diabetic kidney disease history, history of cardiac and vascular diseases, body mass index and smoking history. There was statistically significant difference between these two groups of patients for visual acuity (Z=-2.604, P=0.009). There was no statistically significant difference between these two groups of patients for intraocular pressure before surgery (Z=0.064, P=0.949). The mean follow-up was (20.3±16.4) months with a range from 1 to 47 months. The patients were followed up for visual acuity, intraocular pressure, neovascular glaucoma (NVG), the incidence of retinal detachment, recurrent vitreous hemorrhage, and repeated operation for complications. ResultsVisual acuity (t=-3.932, -8.326; P=0.000, 0.000) and intraocular pressure (t=-3.159, -2.703; P=0.006, 0.009) were changed significantly after surgery for both groups. Between these two groups after surgery, there were significant differences of visual acuity (Z=-1.879, P=0.040), intraocular pressure (Z=-3.593, P=0.000), and complications (revision operation, retinal detachment, recurrent vitreous hemorrhage and NVG) (t=-2.777, -2.102, -2.308, -2.013; P < 0.05). ConclusionIntraocular silicone oil tamponade can reduce the postoperative complications of PDR, especially for severe retinal neovascularization, exudation associated with retinal edema.
OBJECTIVE To search an ideal carrier of transferred keratinocytes for transplantation. METHODS The transferred keratinocytes were seeded on the surfaces of the artificial dermis and the silicone membrane and cultured in vitro for 2 weeks. The growth of the keratinocytes was observed by microscope and scanning electron microscope. RESULTS The keratinocytes implanted on the artificial dermis began to rupture and died after 2 to 3 days. While the keratinocytes adhered well on the surface of silicone membrane with pseudopodia formation after 1 week under scanning electron microscope, and the cells kept normal morphological and proliferative properties 2 weeks later. CONCLUSION The silicone membrane can be applied as an useful carrier for the keratinocytes transplantation.