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 investigate the feasibility of using magnetic resonance imaging (MRI) to measure the visual axis length in silicone oil filled eyeballs. Methods Thirty-two silicone oil-filled eyes of 32 patients were studied. The antesilicone oil spaces (ASS) and retro-silicone oil spaces (RSS) on the visual axis was measured on the cross-sectional T1 weighted images (T1 WI) and T2WI, the length of the visual axis was measured on the fatsuppressed T2WI. The length of the visual axis was the distance from the corneal vertex to the macular fovea, and it was also measured by A-mode ultrasound in sitting position with different ultrasonic velocity. The postoil gap was also measured by A-mode ultrasound in supine position. Results Compared with the signal of the contralateral vitreous body, the silicone oil signal was higher on T1WI images, lower on T2WI images. After fat suppression, the silicone oil signal and chemical shift artifact were reduced. There were different levels of ASS and RSS in the vitreous cavity of all 32 cases, the RSS depth was (2.47plusmn;1.31) mm on average by MRI. However, RSS was detected in only 56.25% (18 cases)eyeballs by A-mode ultrasound. The visual axis length of silicone oil-filled eyes was (23.52plusmn;4.67) mm by MRI, and (20.57plusmn;5.32) mm by A-mode ultrasound in sitting position. The differences between two measurements was statistically significant (t=30.17, P＜0.05). Conclusions In addition to A-mode ultrasound, MRI might be another effective method to detect RSS and ASS, and to measure the axial length of silicone oil-filled eyes.
Silicone oil is widely used in intraocular filling of fundus disease after vitrectomy, which improves retinal reattachment rate andpostoperative visual function of patients. With the era of minimally invasive vitreous surgery coming, the utilization rate of silicone oil filling is decreasing, however, it still plays an indispensable role in the surgical treatment of complex fundus diseases. In the process of using silicone oil, the indications should be strictly selected, and the potential risks should be fully considered and possibly avoided. The study of vitreous substitutes with certain physiological functions is currently a research hotspot in the field of fundus diseases.
Objective To investigate the main causes and risk factors of recurrent retinal detachment (RRD) after silicone oil removal (SOR) in eyes with complex retinal detachment. Methods It was a retrospective case series study. A total of 458 eyes of 455 consecutive patients who underwent pars plana vitrectomy with silicone oil tamponade were recruited in this study. All patients underwent vitrectomy operation. Additionally, they were given heavy water, membrane peeling, retinotomy or partial cutting, intraocular laser photocoagulation or frozen, gas-liquid exchange or direct oil exchange operation accordingly. Ninety-eight eyes with multiple holes, old retinal detachment, hyperplasia and serious traction lesions underwent scleral buckling surgery simultaneously. Intravitreal silicone oil was padded at the end of operation. Cutting, stripping or resection and 360° preventive laser photocoagulation were applied while the epiretinal membrane was found and need treatment during SOR. Holes or suspicious hiatus underwent intraocular laser photocoagulation or cryotherapy during the operation. One week after SOR and during follow-up, the visual acuity, intraocular pressure (IOP), slit lamp microscope, and ophthalmoscope examination were examined with the same technique and methods as preoperation. The eyes were divide into two groups based on the attachment status of retina after SOR, which were reattached group (419 eyes) and redetached group (39 eyes) respectively. The following data were recorded: the age of patients, ocular axial length, logarithm of minimum angle of resolution (logMAR) best corrected visual acuity (BCVA) and IOP before vitrectomy operation and before and after SOR, the number of retinal breaks, the duration of silicone oil filling, the duration of followup, and the related factors during vitrectomy operation and SOR. The relation of age, sex, high myopia, the size and location of holes, aphakic eye, proliferative vitreoretinopathy (PVR) C3 level and above, previous history of failed retinal detachment operation, 360° preventive laser photocoagulation, assistant scleral buckling surgery, SOR via corneal puncture to RRD after SOR were analyzed. Odds ratio (OR) and its 95% confidence interval (CI) were calculated for the age ＜40 years old and gender. High myopia, assistant scleral buckling surgery and SOR via corneal puncture were further analyzed by multiple regression equation. Results After SOR operation, the total average logMAR BCVA was 0.86±0.63. The average logMAR BCVA was 0.82±0.59 and 0.99±0.70 respectively for the reattached and redetached groups, which was not statistically different (F=1.559,P＞0.05). The number of high myopia eyes in the reattached and redetached groups were 116 and 22 eyes, respectively, accounted for 27.7% and 56.4%, and the difference was statistically significant (χ2=13.984,P＜0.01). Three eyes underwent vitrectomy with scleral buckling occured RRD, accounting for 3.1%; while 36 eyes underwent vitrectomy without scleral buckling occured RRD, accounting for 10.0%. The incidence of RRD between them was statistically significant (χ2=4.761,P＜0.05). The incidence of RRD was not retated to the PVR levels before the operation, previous history of failed retinal detachment operation, aphakic eye and preventive laser photocoagulation (OR=1.626, 1.699, 1.986, 0.709; 95%CI:0.836-3.162, 0.832-3.658, 0.921-4.279, 0.268-1.875; P＞0.05) . RRD had a close relation with high myopia and assistant scleral buckling surgery (OR=3.380, 0.284; 95%CI:1.733 -6.595, 0.086-0.944; P＜0.05). The raise of risk derived from SOR via corneal puncture had no statistical significance (OR=2.119; 95%CI: 1.043-4.306; P＞0.05). The incidence of RRD after SOR was 8.5%; of which, 35.9% originated from new breaks and 69.2% were related to new breaks, in contrast, only 5.1% originated from PVR but 51.3% were related to PVR. ConclusionsHigh myopia is an independent prognostic risk factor of RRD after SOR. Combined scleral buckling surgery is a protective factor of RRD after SOR. To the well reattached eyes before SOR, the new breaks seems to be the main cause of RRD, wheras PVR was probably a secondary phenomenon.
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.
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 investigate the time and the mechanism of the toxic and side effects of silicone oil on ocular tissues. Methods 19 human eyeballs were examined histopathologically at different time intervals after silicone oil tamponade. Results Microscopic bubbles presumably containing silicone oil were found in sensory retina,RPE,optic nerve, pre and subretinal membrane,iris,anterior chamber angle,and retrocorneal membrane.In the eyes containing silicone oil for less than 9 months.Silicone bubbles were present only in the surface of retina(within preretinal membrane or macrophages),and after that time,silicone bubbles were noted within sensory retina.In an eye enucleated 39 months after intravitreal silicone tamponade,the parenchyma and subarachnoid space of the optic nerve were found to be diffusely invaded by silicone bubbles. Conclusion The histopathologic changes of ocular tissues are related to the duration of intravitreal silicone oil tamponade. (Chin J Ocul Fundus Dis, 1999, 15: 232-234)
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)
ObjectiveTo investigate the medium and long-term influence of silicon oil versus heavy silicone oil on rabbit retinas. Methods28 health standard rabbits were randomly divided into A, B and C groups, with 12, 12 and 4 rabbits respectively. All rabbits received routine vitrectomy and tamponade with silicone oil (group A), or heavy silicone oil (group B) or balanced salt solution (group C). After 4, 8, 12 and 24 weeks, the retinal b-wave amplitude was measured by ERG, posterior retinal thickness was measured by optical coherence tomography (OCT). Retinal ultrastructure and tissue morphology were observed by transmission electron microscopy and optical microscopy. ResultsCompare to group C, the b-wave amplitude decreased at 4 weeks after surgery, and decreased at 8 weeks after surgery for group B, and decreased at 8 weeks after surgery, and decreased at 24 weeks after surgery for group A. The decreases were greater in group B than group A at 8, 12, 24 weeks after surgery, the difference was statistically significant (P < 0.05). The posterior retinal thickness of group A and B was thinner than group C at 24 weeks after surgery (P < 0.05). The decreases were greater in group B than group A, the difference was statistically significant (P < 0.05). Transmission electron microscopy and optical microscopy revealed severe pathological changes of retinal ultrastructure and morphology in group A and B rabbit eyes, at 12 weeks and 8 weeks after surgery respectively. The changes were more severe in group B and group A, including edema and necrosis in cone/rod cells, in disk membranes, mitochondria, cytoplasm, nucleus and other organelles. The morphological changes were also more severe in group B and group A, including degenerations of ganglion cell layer, inner nuclear layer changes. Those changes became more severe when the tamponade time extended. ConclusionThe heavy silicone influence on visual function, ultrastructures, histomorphology of rabbit retinas is much worse than the silicon oil, and the effect is more significant with its time prolong.
Objective To verify the changes of optics and refraction of the eyes after retinal detachment surgery with the tamponade of silicone oil in vitreous cavity. Methods The optical calculation was taken as the following by using the parameter of Gullstrand model eye:（1）The refraction of silicone filled eye in non-accommodative status;（2）The refraction of silicone filled eye in non-accommodative status;（3）The aniseikonia analysis when one eye filled with the silicone oil;（4）The IOL power re-calculation． Results （1） Compa red with the normal eye,the eye filled with silicone oil is moved toward high hyperopia of +9．19 D;（2）When corrected,the accommodation amplitude reduced 1.42 D induced by filling silicone oil. Conclusion When eye filled with silicone oil,the change of refractive power tends to be highly hyperopic,the amplitude of accommodation decreased,and the regular IOL power calculation formula is no longer available. (Chin J Ocul Fundus Dis，2000，16：139-212)