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 evaluate the incidence of retinal re-detachment and possible risk factors after removal of silicone oil.
MethodsThe clinical data of 821 patients (858 eyes) who underwent removal of silicone oil in General Hospital of PLA during 2008-2012 were retrospectively analyzed. The patients included 518 males and 303 females. The age was ranged from 1 to 79 years old, with an average of 44.03 years. All patients underwent removal of silicone oil after vitrectomy combined with silicone oil tamponade (the tamponade period was ranged from 40 days to 13 years, with an average of 6.82 months). The incidence, time and causes of retinal re-detachment were analyzed.
ResultsRetinal re-detachment occurred in 43 patients (44 eyes, 5.13%). Among these retinal re-detachment in 44 eyes, 23 eyes (52.27%) occurred in 1 week, 13 eyes (29.55%) in 1-4 weeks, 4 eyes (9.08%) in 4-8 weeks, 2 eyes (4.55%) in 8-12 weeks, and 2 eyes (4.55%) more than 12 weeks after silicone oil removal. Possible reasons of retinal re-detachment included activated original retinal holes (7 eyes), residual peripheral vitreous (3 eyes), traction of epiretinal proliferative membrane (18 eyes), new retinal hole (9 eyes), non-closure of original retinal holes (5 eyes) and traction of retinal incarceration in the scleral incision (2 eyes).
ConclusionsThe incidence of retinal re-detachment after silicone oil removal is 5.13%. The incidence reduced gradually with the extension of time after removal silicone oil.
Objective To compare the outcome of C3F8 versus silicone oil intraocular tamponade after pars plana vitrectomy (PPV) for the treatment of severe highly myopic macular hole retinal detachment (MHRD). Methods Thirty-two highly myopic MHRD patients (32 eyes) with extreme long axial lengths (ge;29.0 mm), quot;severequot; retina pigment epithelium (RPE) and chorioretinal atrophy, and posterior staphyloma who underwent PPV, were enrolled in this study. The patients were divided into two groups according to different intraocular tamponade agents: C3F8 (group A, 15 eyes) and silicone oil (group B, 17 eyes). The patients with retinal re-detachment after surgery received PPV again. The differences of sex (P=1.000), age (t=0.444, P=0.660), best-corrected visual acuity (t=0.084, P=0.934), diopter (t=0.449, P=0.978), lens state (P=1.000), time of the symptoms (t=0.375, P=0.710) and degree of retinal detachment (chi;2=0.014, P=0.907) between group A and B were not statistically significant. The anatomic reattachment of the retina, macular hole closure, and vision acuity were observed at one week, one, three, six and 12 months after surgery. Results The rates of retinal reattachment and macular hole closure were 60.00% and 13.33 % in group A, 82.35% and 29.41% in group B in the first time of surgery. There was no difference in rates of retinal reattachment and macular hole closure between two groups (P=0.243, 0.402). The rates of retinal reattachment and macular hole closure were 86.67% and 20.00% in group A, 94.12% and 29.41% in group B in the second time of surgery. There was no difference in rates of retinal reattachment and macular hole closure between two groups (P=0.589, 0.691). Twelve months after surgery, the vision acuity improved in five eyes, unchanged in seven eyes , and decreased in three eyes in group A; the vision acuity improved in seven eyes , unchanged in eight eyes , and decreased in two eyes in group B. The differences of vision result was not statistically significant between two groups (chi;2=0.209, P=0.647). Conclusion The rates of retinal reattachment and macular hole closure with silicone oil tamponade was higher than that with C3F8 tamponade in eyes with severe highly myopic MHRD, but the differences are not statistically significant.
Objective
To evaluate the accuracy of the biometry using immersion B scan and partial coherence interferometry (Lenstar LS900) for the axial length (AL) of silicone oil-filled eyes respectively.
Methods
Thirty-five silicone oil-filled eyes (38 patients) were included in the study. All of these eyes underwent silicone oil removal, cataract extraction and intraocular lenses implantation. The AL of all the silicone oil-filled eyes was measured with A/B-scan ultrasound and Lenstar LS900 before operation and with Lenstar LS900 after operation. The measured distance was compared respectively. The method of immersion B-scan guided with respective sonic velocity. AL was the sum of corneal thickness, anterior chamber depth, lens thickness, the apparent length of oil bubble (velocity values 996 m/s), the depth of the water layer beneath the oil bubble.
Results
Thirty-one eyes were measured with Lenstar LS900 before silicone oil removal, and the mean AL was (24.12±1.70) mm, 7 eyes failed to get the results before the operation; 36 eyes were measured with Lenstar LS900 after silicone oil removal, and the mean AL was (24.45±1.89) mm. All eyes were measured with B-scan before silicone oil removal, and the mean AL was (24.87±2.52) mm. The difference (31 eyes) of AL measurement before silicone oil removal by two methods was (?0.00±0.09) mm; the difference (31 eyes) between pre- and post-surgical AL measurement with Lenstar LS900 was (0.02±0.07) mm; the difference (36 eyes) between pre-surgical AL measured with B-scan and post-surgical AL measured with Lenstar LS900 was (?0.02±0.11) mm. All the differences were not statistically significant (t=?0.205, 1.752, ?1.280; P＞0.05). The consistency of the results measured by two methods was well in Bland-Ahamn analysis.
Conclusions
Measurement results of AL between immersion B-scan guided with respective sonic velocity and Lenstar LS900 are high repeatability on silicone oil-filled eyes. The AL of silicone oil-filled eyes can be measured reliably by immersion B-scan guided with respective sonic velocity.
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.
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 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)
ObjectiveTo compare the safety and efficacy of a modified 23G with suturing incision and traditional 23G vitrectomy for silicone oil removal.
MethodsA total of 177 patients (180 eyes) who underwent silicon oil removal (the average tamponade period was 4.5 months) were enrolled in this prospective study. The patients included 112 males (113) and 65 female (67). The mean age was (43.8±10.3) years. The corrected vision, indirect ophthalmoscopy, intraocular pressure, B-ultrasound and optical coherence tomography were measured for all patients. All patients had no complete retinal detachment. The patients were randomly divided into modified 23G with suturing incision group (group A, 88 eyes) and traditional 23G vitrectomy (group B, 92 eyes). The differences of sex (χ2=1.596), age, corrected vision (t=0.785), intraocular pressure (t=0.352), primary disease (χ2=1.982) and lens condition (χ2=2.605) were not significant (P>0.05). The operation time, intraocular pressure, silicon oil retention, choroidal detachment, retinal redetachment and endoophthalmitis were recorded at the end of the operation.
ResultsThe difference of mean operation time was not significant between group A and B (t=1.950,P>0.05). The differences of mean visual acuity 1 day, 1 week and 3 months after operation were not significant between group A and B (t=0.873, 1.115, 0.141; P>0.05). There was difference of mean intraocular pressure at 1 day after operation (t=2.550,P<0.05), but not at 1 week and 3 months after operation (t=1.451,1.062; P>0.05) between group A and B. There were 25 eyes (28.4%) with intraocular hypotension, 8 eyes (9.1%) with choroidal detachment, 5 eyes (5.7%) with vitreous hemorrhage, 9 eyes (10.2%) with retinal redetachment, and 7 eyes (8.0%) with silicon oil retention in group A. There were 5 eyes (5.4%) with intraocular hypotension, 2 eyes (2.2%) with choroidal detachment, 2 eyes (2.2%) with vitreous hemorrhage, 8 eyes (8.7%) with retinal redetachment, and 1 eye (1.1%) with silicon oil retention in group B. The differences of incidence of intraocular hypotension, choroidal detachment and silicon oil retention were significant (P<0.05). No endoophthalmitis occurred.
ConclusionThe safety of modified 23G with suturing incision is better than traditional 23G vitrectomy for silicone oil removal, with decreased incidence of intraocular hypotension, choroidal detachment and silicon oil retention.
PURPOSE:To assess the effects of silicone oil removal on the complications associated with its use.
METHODS:Retrospective analysis of the results of silicone oil removal after vitreous surgery for retinal detachment in 913 eyes in
National Ophthalmology Centre of French. The follow-up period was at least six months and the mean duration of oil tamon-
ade was 6.4 months.
RESULTS :Retinal detachment recurred in 7.3%. The development of cataract continued after silicone oil removal. No patient retained a clear lens in the eye with oil remained in situ for more than 3 months. TWO of 5 eyes with
keratopathy at the time of oil removal recovered after the oil removal ;but the corneas of another 4 eyes became dystrophic after the oil removal. Twelve of 15 eyes with secondary ocular hypertension incontrollable through medicinal treatment relieved after oil removal ,but another 11 eyes became hypertensive after oil removal. Persistent emulsive droplets wre found in anterior chamber angles of the above 11 hypertensive eyes and the 7 eyes with keratopathy.
CONCLUSINOS:Early removal of silicone oil after retinal detachment operation might delay the development of cataract but can not avoid its occurence ,and ocular hypeitension and keratopathy can be prevented by early and complete removal of silicone oil.
Chin J Ocul Fundus Dis,1997,13: 22-23）
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.
