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.
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 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)
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 evaluate glaucoma and anterior chamber angle changes after intravitreal silicone oil injection(SOI). Methods The intraocular pressure(IOP) and anterior chamber angles of 34 e yes(33 patients)undergone pars plana vitrectomy and SOI were observed. Results Glaucoma occurred in 9 eyes(26%),in which silicone oil glaucoma(SOG) accounted for 77%(7/9).The changes of the superior part of anterior chamber angle were peripheral anterior synechiae in 11 eye(32%) and SO emulsification droplets in 22 eyes(64%) in 1～4.5 months after surgeries.Glaucoma occurred in 6 eyes of 7 eyes undergone peripheral iridectomy at the inferio r part of the iris after the closure of iridectomy holes (plt;0.05). Conclusion High incidence of glaucoma was found in this series of patients after intravitreal silicone oil injection,and the main causes of SOG were closure of the inferior iridecomy hole and silicone emulsification. (Chin J Ocul Fundus Dis, 2001,17:105-107)
ObjectiveTo observe the changes in physical properties of silicone oil after intraocular tamponade. MethodsThe silicone oil was removed from 99 patients (99 eyes) of primary retinal detachment with 23G vitreous cutter system. The upper silicone oil was collected after put the vitrectomy samples at room temperature for 3 days. According to the time of intraocular tamponade, the silicone oil samples were divide into six groups including group A (1 month, 12 samples), group B (2 months, 15 samples), group C (3 months, 25 samples), group D (6 months, 22 samples), group E (1-2 years, 13 samples) and group F (above 2 years, 12 sample). Fresh unused silicone oil was set as blank control group. Then the emulsion particles, kinematic viscosity, surface tension, density, transmittance and refractive index were measured. ResultsThe difference between group A-F and the control was statistical significant (P<0.05) in emulsion particles (F=89.337), kinematic viscosity (F=10.660), surface tension (F=11.810), density (F=13.497), transmittance of wavelengths (F=455.496, 566.105, 525.102, 767.573, 622.961, 601.539), but not statistical significant at refractive index (F=2.936, P>0.05). The number of silicone oil emulsion particles has no statistical difference between group A and the control (P>0.05), but was significantly different between group B-F (P<0.05). The kinematic viscosity of silicone oil has no statistical difference between group A, B and the control (P>0.05), but was significantly different between group C-F (P<0.05). The surface tension of silicone oil has no statistical difference between group A-D and the control (P>0.05), but is significantly different between group E and F (P<0.05). The density of silicone oil has no statistical difference between group A-D and the control (P>0.05), but was significantly different between group E and F (P<0.05). The transmittance of silicone oil has statistical difference between group A-F and the control(P<0.05). The refractive index of silicone oil has no statistical difference between all the groups and the controls significantly (P>0.05). ConclusionsThe physical properties of silicone oil will change during the intraocular tamponade. The emulsion particles number will increase and the transmittance will decrease after 2 months, the kinematic viscosity of silicone oil will decrease significantly after 3 months, and the density and surface tension will change significantly after 1 year of tamponade.
Objective To evaluate the relative factors of effect of vitrectomy on corneal endothelial cells. Methods Retrospective analysis of the results of corneal endothelium microscopy performed on 213 eyes of 213 patients undergone vetrectomy operations including single vitrectomy (78 eyes), vitrectomy combined with cataract extraction (135 eyes), silicone oil injection (34 eyes), and C3F8 injection (53 eyes) before and after 1 week, 1 and 3 moths of these surgical procedures. Results There was no significant difference between pre- and postoperative corneal endothelium density in single vitrectomy group and vitrectomy combined with cataract extraction with posterior capsule integrity group (Pgt;0.05). The corneal endothelium density significantly decreased postoperatively in C3F8or silicone oil injection group with broken posterior capsule (Plt;0.05). Conclusion C3F8 and silicone oil may damnify corneal endothelium in patients undergo vitrectom y combined with cataract extraction with broken posterior capsule. (Chin J Ocul Fundus Dis，2004，20：101-103)
Objective To observe the effects of vitrectomy combined with endotamponade on severe endophthalmitis. Methods The clinical data of 44 patients (44 eyes) of posttraumatic and 22 patients (22 eyes) of postoperative severe endophthalmitis were retrospectively analyzed. All patients were treated by vitrectomy and endotamponade. Intraocular foreign body removal (19 eyes), lens extraction (25 eyes), intraocular lens removal (six eyes) and scleral buckling (16 eyes) were performed. Tamponade with silicone oil (52 eyes) or C3F8 gas (14 eyes) was also performed. Postoperative follow-up ranged from two to 25 months, with the mean of 7-9 months. The visual acuity（VA）and intraocular pressure before and after surgery were comparatively analyzed. Results Inflammation of all the patients were controlled，the effective rate was 5.10%. There was no recurrence and retinal detachment. Among the 66 eyes, postoperative VA of 58 eyes (87.90%) increased,five eyes（7.60%）didn't change and three eyes（4.55%）decreased, the difference was statistically significant（chi;2=45.27，P＜0.05）. The postoperative intraocular pressure was higher than that before surgery，the difference was statistically significant（t=-3.23，P＜0.05）. Conclusions Vitrectomy combined with endotamponade is an effective way to cure severe endophthalmitis. It can improve the visual acuity and intraocular pressure.