Silicone oil as a corneal lubricant to reduce corneal edema and improve visualization during

AIM:To evaluate the efficacy and safety of silicone oil(SO)as a corneal lubricant to improve visualization during vitrectomy.METHODS:Patients who underwent vitreoretinal surgery were divided into two groups.Group 1 was operated on with initial SO(Oxane 5700)as a corneal lubricant.Group 2 was operated on with initial lactated ringer’s solution(LRS)and then replaced with SO as required.Fundus clarity was scored during the surgery.Fluorescein staining was performed to determine the damage to corneal epithelium.RESULTS:Totally 114 eyes of 114 patients were included.Single SO use maintained a clear cornea and provided excellent visualization of surgical image.In group 1,the fundus clarity was grade 3 in 41/45 eyes and grade 2 in 4/45 eyes.In group 2,corneal edema frequently occurred after initial LRS use.The fundus clarity was grade 3 in 19/69 eyes,2 in 37/69 eyes and 1 in 13/69 eyes(P<0.05).SO was applied in 29 eyes of initial LRS use with subsequent corneal edema,which eliminated the corneal edema in 26 eyes.Corneal fluorescein staining score in group 1 was 0 in 28 eyes,1 in 11 eyes and 2 in 6 eyes,and 40,20 and 9,respectively,in group 2(all P>0.05).CONCLUSION:The use of SO as a corneal lubricant is effective and safe for preserving and improving corneal clarity and providing clear surgical field during vitrectomy.

The Various Complications Associated with Use of Silicone Oil in Rhegmatogenous Retinal Detachment (RRD) Surgery via Three-Port Vitrectomy (3PV): A Retrospective Study at the Ophthalmology Center of Abass Ndao Hospital

Introduction: RRD (Rhegmatogenous Retinal Detachment) is a separation between the neuroepithelium and the pigment epithelium due to the passage of fluid through a retinal dehiscence. It constitutes a major ophthalmologic emergency. Its management is primarily surgical, either through external or internal approaches, with tamponade using gas or silicone oil. The purpose of this study was to report the various complications associated with the use of silicone oil in vitreoretinal surgery. Patients et methods: We conducted a retrospective, descriptive, and analytical study from October 1, 2020, to October 31, 2023, which included all patients who underwent surgery for RRD using three-port vitrectomy (3PV) with tamponade using 1000 centistoke silicone oil (Group 1) and 5000 centistoke silicone oil (Group 2). All patients underwent a complete ophthalmologic examination and were operated on by the same surgeon. Data analysis was performed using Excel software. Results: Overall, 31 patient files representing 33 eyes were collected, with a mean age of 48.83 years and a sex ratio of 4.16. Group 1 consisted of 16 eyes (48.48%), and Group 2 consisted of 17 eyes (51.51%). The different complications observed were cataracts in all phakic subjects, accounting for 57.57%;ocular hypertonia in 69.69% (27.27% in Group 1;42.42% in Group 2);anterior chamber silicone oil migration in 24.24% (9.09% in Group 1;15.15% in Group 2);recurrence of retinal detachment in 21.21% (6.06% in Group 1;15.15% in Group 2);and silicone oil emulsification in 24.24% (15.15% in Group 1;9.09% in Group 2). Additionally, there was one case of corneal degeneration in Group 1. Conclusion: Silicone oil is an effective tamponade agent used in the treatment of retinal detachments. Close patient follow-up is necessary due to the complications associated with its use, which can occur either early or late after surgery.

Non-contact wide-field viewing system-assisted scleral buckling surgery for retinal detachment in silicone oilfilled eyes

AIM:To evaluate scleral buckling(SB)surgery using a noncontact wide-field viewing system and 23-gauge intraocular illumination for the treatment of rhegmatogenous retinal detachment in silicone oil(SO)-filled eyes.METHODS:Totally 9 patients(9 eyes)with retinal detachment in SO-filled eyes were retrospectively analyzed.All patients underwent non-contact wide-field viewing system-assisted buckling surgery with 23-gauge intraocular illumination.SO was removed at an appropriate time based on recovery.The patients were followed up for at least 3mo after SO removal.Retinal reattachment,complications,visual acuity and intraocular pressure(IOP)before and after surgery were observed.RESULTS:Patients were followed up for a mean of 8.22mo(3-22mo)after SO removal.All patients had retinal reattachment.At the final follow-up,visual acuity showed improvement for 8 patients,and no change for 1 patient.The IOP was high in 3 patients before surgery,but it stabilized after treatment;it was not affected in the other patients.None of the patients had infections,hemorrhage,anterior ischemia,or any other complication.CONCLUSION:This new non-contact wide-field viewing system-assisted SB surgery with 23-gauge intraocular illumination is effective and safe for retinal detachment in SO-filled eyes.

Silicone oil migrating into the conjunctival space and orbit after surgery for an eye-penetrating injury:A case report

BACKGROUND We report a case of eye-penetrating injury in which a massive silicone oil migration into the patient’s subconjunctival space and orbit occurred after vitrectomy.CASE SUMMARY A 30-year-old male patient sought medical attention at Ganzhou People’s Hospital after experiencing pain and vision loss in his left eye due to a nail wound on December 9,2023.Diagnosis of penetrating injury caused by magnetic foreign body retention in the left eye and hospitalization for treatment.On December 9,2023,pars plana vitrectomy was performed on the left eye for intraocular foreign body removal,abnormal crystal extraction,retinal photocoagulation.Owing to the discovery of retinal detachment at the posterior pole during surgery,silicone oil was injected to fill the vitreous body,following which upper conjunctival bubble-like swelling was observed.Postoperative orbital computed tomography(CT)review indicated migration of silicone oil to the subconjunctival space and orbit through a self-permeable outlet.On December 18,2023,the patient sought treatment at the First Affiliated Hospital of Nanchang University,China.The patient presented with a pronounced foreign body sensation following left eye surgery.On December 20,2023,the foreign body was removed from the left eye frame and an intraocular examination was conducted.The posterior scleral tear had closed,leading to termination of the surgical procedure following supplementary laser treatment around the tear.The patient reported a significant reduction in ocular surface symptoms just one day after surgery.Furthermore,a notable decrease in the migration of silicone oil was observed in orbital CT scans.CONCLUSION The timing of silicone oil injection for an eye-penetrating injury should be carefully evaluated to avoid the possibility of silicone oil migration.

Endophthalmitis in silicone oil-filled eye: A case report

BACKGROUND Endophthalmitis occurring in silicone oil-filled eyes is a very rare occurrence,with reported incidence rates ranging between 0.07%and 0.039%.Traditional methods of management of infectious endophthalmitis include the removal of silicone oil,washout of the vitreous cavity,administration of intravitreal antibiotics,and reinjection of silicone oil.CASE SUMMARY Herein,we report the case of a 39-year-old man with unilateral endophthalmitis after pars plana vitrectomy and silicone oil tamponade.Intravitreal injections of full-dose antibiotics and anterior chamber washout were used to treat the patient.No signs of retinal toxicity were observed during the follow-up period.CONCLUSION Intravitreal full-dose antibiotic injections and anterior chamber washout are promising alternatives to traditional therapies for endophthalmitis in silicone oilfilled eyes.

Research Progress of Carbon-Silicone Composite Materials

Silicone is a kind of polymer material with high cross-linked structure,which is com-posed by Si-O-Si main chain.Due to the special molecular chain structure,silicone mate-rials are characterized by oxidation resistance,aging resistance,high and low temperature resistance and chemical corrosion resistance.Moreover,silicone materials have process-able properties,simple forming process,good mechanical property,non-toxic and pollution-free.Therefore,silicone has been widely concerned by researchers at home and abroad.In this paper,the main research progress and application directions of carbon-silicone composite at home and abroad in recent years are reviewed.

乳腺假体并发症的Silicone序列MRI特征

目的分析乳腺假体植入术后并发症的MRI表现,探讨其诊断价值。方法回顾性分析本院2013年6月至2015年6月收治的9例乳腺假体MRI特征。结果 1假体退行性样改变:Silicone-Sup序列上表现为片状不规则混杂信号或气泡样无信号结节。2假体包膜挛缩、假体变形移位:表现为假体边缘呈波浪状,囊壁增厚。3假体破裂(分囊内破裂和包膜破裂):囊内破裂Silicone-only序列表现囊内曲线状、弧线状低信号;包膜破裂表现为假体包膜连续性中断、假体周围间隙内存在结节状或片状假体信号。结论 MRI是诊断乳腺假体并发症的首选方法,视野全面,无需压迫,诊断准确率高。

EVA与Silicone密封剂封装对选择性发射极太阳电池效率的影响研究

：在构建选择性发射极太阳电池组件光学模型的基础上，引入分贝概念，并在此基础上给出太阳电池组件的外量子效率和内量子效率定义式，使研究太阳电池组件中各部分封装材料对其光电转换效率的影响更加方便。根据密封剂EVA和Silicone的光透射率测量数据，计算两种密封剂在280～1200nm波段内的吸收损耗。使用光谱响应测试仪分别测量密封剂EVA和Silicone封装的单片电池片在封装前后的量子效率，计算两种密封剂在短波段300～500nto处为选择性发射极电池组件带来的短路电流密度衰减。经比较得出，选择性发射极太阳电池组件使用密封剂Silicone封装可提高其短波响应，提高量子效率。

低能质子辐照ZnO/silicone白漆产生微观损伤的红外光谱研究

通过空间综合辐照模拟设备对能量小于200 keV质子辐照下ZnO/silicone白漆光学性能变化及损伤机理进行研究。结果表明,ZnO/silicone白漆的光学性能退化主要发生在可见光区,太阳吸收比随质子辐照能量、注量的增加而增大。借助傅里叶变换红外光谱分析技术研究了质子辐照ZnO/silicone白漆时有机硅树脂的光学性能退化机理。质子辐照使ZnO/silicone白漆中游离氧含量增加,氧化硅原子上的有机取代基使Si—C链断裂,并生成活性羟基,而这种活性羟基能促使有机硅树脂内Si—O—Si键的裂解。同时Si—O—Si链内氧原子未成键的孤对电子与邻近硅原子的3d空轨道配位,降低了π*轨道的能量,提高了对光吸收的几率,增强了n→π*电子跃迁,使吸收带红移,从而导致ZnO/silicone白漆光学性能退化。

Vitrectomy, lensectomy and silicone oil tamponade in the management of retinal detachment associated with choroidal detachment

AIM: To report the results of combined vitrectomy, lensectomy and silicone oil (SO) tamponade in treating primary rhegmatogenous retinal detachment (RRD) associated with choroidal detachment (CD). · METHODS: A retrospective, consecutive and case series study of 21 subjects with concurrent RRD associated with CD was conducted. All subjects underwent a standard three -port 20G pars plana vitrectomy (PPV) with lensectomy and silicone oil tamponade. Mean follow -up time was 8 months (rang from 4 to 19 months). The primary and final anatomic success rate, visual acuity and final intraocular pressure (IOP) were recorded and analyzed. ·RESULTS: Of 21 subjects, 8 were women and 13 were men. Age at presentation ranged from 22 to 75 years (mean 57.4 years). The presenting vision ranged from light perception to 0.15. The initial IOP ranged from 3mmHg to 12mmHg (mean 6.2mmHg). All eyes were phakic except one pseudophakic. No intraocular lens was implanted during the primary surgical intervention. Fifteen of 21 (71.4%) eyes had retina reattached after one operation. Six eyes had recurrent inferior retinal detachment due to proliferation. Five of them were successfully reattached after one or more additional operations. Mean IOP at final follow -up was 15.2mmHg (range from 8mmHg to 20mmHg). One case declined for further operation. The final reattachment rate was 95.2%. Visual acuity improved in 19 (90.5%) eyes, was unchanged in 1 (4.8%) eye and decreased in 1 (4.8%) eye.·CONCLUSION: Combination of vitrectomy, lensectomy and silicone tamponade is an effective method in treating RRD associated with CD, reducing the incidence of postoperative hypotony.

Analysis of the causative factors related to earlier emulsification of silicone oil

The aim of this study is to report and analyze the factors related with earlier occurrence of silicone oil(SO) emulsification in patients underwent pars plana vitrectomy and SO injection in our hospital. We retrospectively reviewed consecutive case series undergone both SO injection and removal in our hospital, and 182 ones were eligible. Possible related independent factors included: macula status(on/off), concomitant phacoemulsification with the surgery of SO tamponading, concomitant status of proliferative vitreoretinopathy, combined surgery of retinotomy, time to have emulsification(<6 mo/≥6 mo after primary SO injection), route of SO injection(anterior/posterior), lens status(aphakic/pseudophakic/phakic), anesthesia(local/general), brands and type of SO, with/without episcleral cryotherapy, with/without hypertension, with/without diabetes, with/without intraoperative use of triamcinolone acetonide. The study revealed that brand and type of SO was the significant factor related with earlier emulsification of SO. Further study was warranted to find out the underlying causes.

Macular Perfusion Changes and Ganglion Cell Complex Loss in Patients with Silicone Oil-related Visual Loss

Objective The aim of this study was to investigate macular perfusion changes and ganglion cell complex(GCC)loss in patients with unexplained visual loss following vitrectomy and silicone oil(SO)tamponade,and to evaluate the correlation between retinal blood flow and GCC loss using optical coherence tomography angiography(OCTA)and optical coherence tomography(OCT).Methods This retrospective study included seven eyes(seven patients)with unexpected visual loss after vitrectomy and SO tamponade.OCTA was used to evaluate the alterations in retinal vessel density(VD)in the superficial capillary plexus(SCP),deep capillary plexus(DCP),and radial peripapillary capillary plexus(RPCP).OCT was used to measure the thickness of GCC and retinal nerve fiber layer(RNFL).Medical records of patients were reviewed.Results Quantitative analysis of OCTA images revealed a significant reduction in SCP VD in the affected eyes compared with the controls(all sections P<0.05).No difference was found in GCC thickness,but FLV(focal loss volume)and GLV(global loss volume)were significantly higher in the affected eyes(both P<0.001).SCP VD was inversely correlated with FLV and GLV.Conclusions Silicone oil-related severe visual loss was associated with superficial retinal microvasculature damage and ganglion cell apoptosis.

Silicone-covered biodegradable magnesium stent for treating benign esophageal stricture in a rabbit model

BACKGROUND Stent insertion can effective alleviate the symptoms of benign esophageal strictures(BES).Magnesium alloy stents are a good candidate because of biological safety,but show a poor corrosion resistance and a quick loss of mechanical support in vivo.AIM To test the therapeutic and adverse effects of a silicone-covered magnesium alloy biodegradable esophageal stent.METHODS Fifteen rabbits underwent silicone-covered biodegradable magnesium stent insertion into the benign esophageal stricture under fluoroscopic guidance(stent group).The wall reconstruction and tissue reaction of stenotic esophagus in the stent group were compared with those of six esophageal stricture models(control group).Esophagography was performed at 1,2,and 3 weeks.Four,six,and five rabbits in the stent group and two rabbits in the control groups were euthanized,respectively,at each time point for histological examination.RESULTS All stent insertions were well tolerated.The esophageal diameters at immediately,1,2 and 3 wk were 9.8±0.3 mm,9.7±0.7 mm,9.4±0.8 mm,and 9.2±0.5 mm,respectively(vs 4.9±0.3 mm before stent insertion;P<0.05).Magnesium stents migrated in eight rabbits[one at 1 wk(1/15),three at 2 wk(3/11),and four at 3 wk(4/5)].Esophageal wall remodeling(thinner epithelial and smooth muscle layers)was found significantly thinner in the stent group than in the control group(P<0.05).Esophageal injury and collagen deposition following stent insertion were similar and did not differ compared to rabbits with esophageal stricture and normal rabbits(P>0.05).CONCLUSION Esophageal silicone-covered biodegradable magnesium stent insertion is feasible for BES without causing severe injury or tissue reaction.Our study suggests that insertion of silicone-covered magnesium esophageal stent is a promising approach for treating BES.

Comparison of Densiron 68 and 1 000 cSt silicone oil in the management of rhegmatogenous retinal detachment with inferior breaks

AIM:To compare success rates and complications of Densiron 68 and 1000cSt silicone oil (SO) in the management of rhegmatogenous retinal detachment (RRD) with inferior breaks (IBs). METHODS:Totally 61 eyes of 61 consecutive patients with RRD with IBs were assigned to pars plana vitrectomy (PPV) with Densiron (n =31) or PPV with SO (n=30) in order of presentation. SO and Densiron removal was performed 3 months after initial surgery. Follow up visits were terminated 6 months after SO removal. ·RESULTS:With a single operation, the Densiron group showed 84% and SO 74% reattachment. With further surgery, both groups showed 90% reattachment. Complications such as cataract, raised intraocular pressure (IOP), inflammatory reaction, macular epiretinal membranes, and emulsification of SO were seen in both groups. CONCLUSION:Densiron and SO are found to have similar success rates and complications.

A comparison between monocanalicular and pushed monocanalicular silicone intubation in the treatment of congenital nasolacrimal duct obstruction

AIM: To compare the success rate of monocanalicular versus pushed monocanalicular silicone intubation(PMCI)of the nasolacrimal duct for congenital nasolacrimal duct obstruction(CNLDO).METHODS: In a prospective randomized clinical trial 53 eyes of 49 patients with CNLDO underwent either monocanalicular silicone intubation(MCI)(n =28 eyes) or PMCI(n =25 eyes). All procedures were performed by 1oculoplastic surgeon. Treatment success was defined as the complete resolution of epiphora at 3mo after tube removal.RESULTS: The surgical outcome was assessed in 20 eyes with MCI and 20 eyes with PMCI. The mean age of treatment was 26.25 ±10.08mo(range, 13-49mo) for MCI and 26.85±12.25mo(range, 16-68mo) for PMCI. Treatment success was achieved in 18 of 20 eyes(90.0%) in the MCI group compared with 10 of 20 eyes(50%) in the PMCI group(P =0.01). In the PMCI group, the tube loss(30%)was greater than the MCI group(5%), however the differences between the 2 groups proved to be not significant(P =0.91).CONCLUSION: Our results indicate that MCI has higher success rate in CNLDO treatment compared with PMCI in this small series of patients.

MODIFICATION OF CeO_2 AND ITS EFFECT ON THE HEAT-RESISTANCE OF SILICONE RUBBER

By means of the wet chemical surface modification,the surface of CeO_2 was modified by vinyltrimethoxysilane (VTMS).Infrared spectroscopy was used to investigate the structure of the modified CeO_2 and the result showed that VTMS has been attached onto the surface of CeO_2.Effect of VTMS concentration on the active index of the modified CeO_2 was also studied,and the result indicated that the active index of the modified CeO_2 increases with the increase of VTMS concentration and the optimal concentration o...

Clinical presentation of a mixed 23-gauge infusion and 20-gauge pars plana technique for active silicone oil removal

AIM: To present with a clinical case series of a mixed 23-gauge infusion and 20-gauge pars plena technique for 5,700-centipoise silicone oil removal (SOR), and to discuss its efficacy and safety. METHODS: This is a retrospective, non-randomized controlled study. We performed SOR with 23-gauge infusion and 20-gauge active suction technique on 29 patients 29 eyes from April to October, 2011 (mixed group). During the surgeries, a 23-gauge sclerotomy was made for infusion and a 20-gauge sclerotomy was used for active silicone oil suction. Anterior segment optical coherence tomography (OCT) was applied for 23-gauge sclerotomy analysis 1 day post-operation. Traditional 20-gauge SOR was performed on another consecutive 29 patients 29 eyes, the control group (20G group). RESULTS: There were 2 eyes (6.9%) in mixed group and 5 eyes (17.2%) in 20G group which had recurrent retinal detachment after surgery. Hopytony (IOP <= 6mmHg) occurred in 8 eyes (27.6%) of mixed group and in 10 eyes (34.5%) of 20G group post-operation, but all of them recovered to the normal level finally. There were no statistical significant differences. Final visual acuity was significantly increased after surgery in both groups. Anterior segment OCT images were acquired from 13 eyes of mixed group, and all of them had a proper wound apposition. But local ciliary detachment was found in 9 eyes (69%). It was hard to define the OCT image of the sclerotomies and ciliary body because of the serious conjunctival hemorrhages and chemosis in 20G group. CONCLUSION: This mixed technique is a convenient and effective way to remove high viscosity silicone oil. Compared with traditional 20-gauge SOR, it does not increase the risk of post-operative complications and has less conjunctival reactions.. Transient postoperative hypotony is common for this procedure and subclinical ciliochoroidal detachment is a probable cause.

INFLUENCES OF MODIFIERS ON SURFACE PROPERTIES OF WHITE CARBON BLACK AND MECHANICAL PROPERTIES OF SILICONE RUBBER

Various of modifiers were used to modify the surface activity of white carbon black. The oil absorption, viscosity, hydrophobic rate and burning loss of white carbon black and the mechanical propertiess of silicone rubber were measured. The influences of the modifiers on the properties of white carbon black and the mechanical properties of silicone rubber were discussed.

Visual outcome after removal of silicone oil in patients undergoing retinectomy for complex retinal detachment

AIM：To evaluate the functional outcome after removal of silicone oil（ROSO）in patients undergoing retinectomy for complex retinal detachment.·M ETHODS：We performed a retrospective case note review of patients who underwent ROSO after retinectomy for complex retinal detachment.Patients with less than 6mo follow up and recurrent retinal detachment following ROSO were excluded.·RESULTS：Thirty-six patients were included.The mean best corrected visual acuity（BCVA）pre-ROSO was1.13 log MAR（SD 0.5）.The mean BCVA 3mo following ROSO was 1.16 log MAR（SD 0.53）,6mo following ROSO1.13（SD 0.63）,and 12mo following ROSO 1.18（SD 0.69）.At 12mo after ROSO,the BCVA improved in 38.9%of patients,remained unchanged in 25%,and deteriorated in 36.1%,although there was no statistical significant difference in BCVA after ROSO at 3,6 and 12mo（=0.93）.The size of retinectomy ranged from 15°to 270°（SD 53）and did not influence the visual outcome（=0.11）.·C ONCLUSION：There was no statistically significant difference in BCVA between pre-and post-ROSO following retinectomy for complex retinal detachment.There was no statistical difference in visual outcome related to the size of the retinectomy.

Vitrectomy combined with silicone oil tamponade in the treatment of severely traumatized eyes with the visual acuity of no light perception

AIM: To evaluate the efficacy of surgical treatment of vitrectomy combined with silicone oil tamponade in the treatment of severely traumatized eyes with the visual acuity of no light perception (NLP).METHODS: This was a retrospective uncontrolled interventional case-series of 19 patients of severely traumatized eyes with NLP who underwent vitrectomy surgery at the Affiliated Hospital of Medical College, Qingdao University (Qingdao, China) during a 3-year period. We recorded perioperative factors with the potential to influence functional outcome including duration from the injury to intervention; causes for ocular trauma; open globe or closed globe injury; grade of vitreous hemorrhage; grade of endophthalmitis; grade of retinal detachment; size and location of intraocular foreign body (IOFB); extent and position of retinal defect; grade of proliferative vitreoretinopathy (PVR); type of surgery; perioperative complications and tamponade agent. The follow-up time was from 3 to 18 months, and the mean time was 12 months.RESULTS: After a mean follow-up period of 12 months (3-18 months) 10.53% (2/19) of eyes had visual acuity of between 20/60 and 20/400, 52.63% (10/19) had visual acuity less than 20/400 but more than NLP, and 36.84% (7/19) remained NLP. Visual acuity was improved from NLP to light perception (LP) or better in 63.16% (12/19) of eyes and the rate of complete retinal reattachment was 73.68% (14/19). Good visual acuity all resulted from those patients of blunt trauma with intact eyewall (closed globe injury). The perioperative factors of poor visual acuity prognosis included delayed intervention; open globe injury; endophthalmitis; severe retinal detachment; large IOFB; macular defect; a wide range of retinal defects andsevere PVR.CONCLUSION: The main reasons of NLP after ocular trauma are severe vitreous hemorrhage opacity; refractive media opacity; retinal detachment; retinal and uveal damages and defects, especially defects of the macula; PVR and endophthalmitis. NLP after ocular trauma in some cases does not mean permanent vision loss. Early intervention of vitrectomy combined with silicone oil tamponade and achieving retinal reattachment of the remaining retina, may make the severely traumatized eyes regain the VA of LP or better.