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.

Axial length,vitreoretinal pathology,and anterior chamber depth can predict postoperative refractive outcomes in phacovitrectomy/silicone oil removal

AIM:To evaluate the postoperative refractive prediction error(PE)and determine the factors that af fect the refractive outcomes of combined pars plana vitrectomy(PPV)or silicone oil removal(SOR)with cataract surgery.METHODS:The study is a retrospective,case-series study.Totally 301 eyes of 301 patients undergoing combined PPV/SOR with cataract surgery were enrolled.Eligible individuals were separated into four groups according to their preoperative diagnoses:silicone oil-filled eyes after PPV(group 1),epiretinal membrane(group 2),macular hole(group 3),and primary retinal detachment(RD;group 4).The variables af fecting postoperative refractive outcomes were analyzed,including age,gender,preoperative best-corrected visual acuity(BCVA),axial length(AL),keratometry average,anterior chamber depth(ACD),intraocular tamponade,and vitreoretinal pathology.The outcome measurements include the mean refractive PE and the proportions of eyes with a PE within±0.50 diopter(D)and±1.00 D.RESULTS:For all patients,the mean PE was-0.04±1.17 D,and 50.17%of patients(eyes)had a PE within±0.50 D.There was a significant difference in refractive outcomes among the four groups(P=0.028),with RD(group 4)showing the least favorable refractive outcome.In multivariate regression analysis,only AL,vitreoretinal pathology,and ACD were strongly associated with PE(all P<0.01).Univariate analysis revealed that longer eyes(AL>26 mm)and a deeper ACD were correlated with hyperopic PE,and shorter eyes(AL<26 mm)and a shallower ACD were correlated with myopic PE.CONCLUSION:RD patients have the least favorable refractive outcome.AL,vitreoretinal pathology,and ACD are strongly associated with PE in the combined surgery.These three factors affect refractive outcomes and thus can be used to predict a better postoperative refractive outcome in clinical practice.

Predictive factors of epiretinal membrane in complicated rhegmatogenous retinal detachment tamponaded with silicone oil

AIM:To determine the incidence and predictive factors for epiretinal membrane(ERM)formation in eyes with complicated primary rhegmatogenous retinal detachment(RRD)tamponaded with silicone oil(SO).METHODS:This retrospective case-control study included 141 consecutive patients with(51 eyes)and without(90 eyes)ERM formation after primary pars plana vitrectomy(PPV)and SO tamponade for complicated RRD.The risk factors for ERM were assessed using logistic regression analysis.RESULTS:The prevalence of postoperative ERM was 36.2%(51/141).Multivariate logistic regression analysis showed that the risk factors for ERM in SO-tamponaded eyes included preoperative proliferative vitreoretinopathy[PVR;odds ratio(OR),2.578;95%confidence interval(CI)1.580–4.205,P<0.001],preoperative choroidal detachment(OR,4.454;95%CI 1.369–14.498,P=0.013),and photocoagulation energy(OR,2.700;95%CI 1.047–6.962,P=0.040).The duration of the preoperative symptoms,intraocular SO tamponade time,giant retinal tear,preoperative vitreous hemorrhage,preoperative bestcorrected visual acuity,number of breaks,quadrants of RRD,axial length,and photocoagulation points were not predictive factors for ERM formation.CONCLUSION:Preoperative PVR,choroidal detachment,and photocoagulation energy are risk factors of ERM formation after complicated RRD repair.Better ophthalmic care as well as patient education are necessary for such patients with risk factors.

Retrolaminar migration as a complication of intraocular silicone oil injection detected on unenhanced CT

AIM:To describe the clinical and radiologic features of retrolaminar migration silicone oil(SiO)and observe the dynamic position of ventricular oil accumulation in supine and prone.METHODS:For this retrospective study,29 patients who had a history of SiO injection treatment and underwent unenhanced head computed tomography(CT)were included from January 2019 to October 2022.The patients were divided into migration-positive and negative groups.Clinical history and CT features were compared using Whitney U and Fisher’s exact tests.The dynamic position of SiO was observed within the ventricular system in supine and prone.CT images were visually assessed for SiO migration along the retrolaminar involving pathways for vision(optic nerve,chiasm,and tract)and ventricular system.RESULTS:Intraocular SiO migration was found in 5 of the 29 patients(17.24%),with SiO at the optic nerve head(n=1),optic nerve(n=4),optic chiasm(n=1),optic tract(n=1),and within lateral ventricles(n=1).The time interval between SiO injection and CT examination of migration-positive cases was significantly higher than that of migration-negative patients(22.8±16.5mo vs 13.1±2.6mo,P<0.001).The hyperdense lesion located in the frontal horns of the right lateral ventricle migrated to the fourth ventricle when changing the position from supine to prone.CONCLUSION:Although SiO retrolaminar migration is unusual,the clinician and radiologist should be aware of migration routes.The supine combined with prone examination is the first-choice method to confirm the presence of SiO in the ventricular system.

Intraocular Silicone Oil Removed after 10 Years: A Case Report

Background: Silicone oil (SO) has been demonstrated with concrete efficacy and safety in the therapy of complex vitreoretinal diseases. SO is schemed to be cleared within several weeks or months after tamponade, but it’s inevitable for permanent or residual SO in a fraction of patients under extremely complicated clinical conditions. Here, we presented a case of silicone oil removal after 10 years, mainly to observe the disadvantages of long-term persistence. Case presentation: A 69-year-old female with pathologic myopia denied trauma history who had undergone pars plana vitrectomy (PPV), retinal reattachment, laser, and silicone oil tamponade in 2012 presented to our hospital with eye pain and headache, no light perception of her right eye for six months. The slit-lamp biomicroscopy examination for OD indicated evident conjunctival congestion, new blood vessels invasion to the limbus, foggy edema of corneal epithelium, folds of Descemet’s membrane and corneal endothelial edema. There were obvious emulsified silicone oil particles above the anterior chamber. Goldmann’s applanation tonometry test revealed the intraocular pressure was as high as 45/17mmHg. From ocular ultrasound, we saw that the vitreous cavity was filled with silicone oil in right eye;as for the left eye, it showed marked axial elongation and posterior scleral staphyloma. We were unable to obtain more information from fundus photography and macular optical coherence tomography (OCT) due to edema of the cornea. After the silicone oil was removed successfully from her vitreous cavity, although there was no improvement in the patient’s vision (no light perception), she was still satisfied with the relief from eye pain and headache benefited from the reduction of high intraocular pressure (Goldmann’s intraocular pressure decreased to 19/14mmHg). Conclusion: Patients after PPV should remove silicone oil in time to avoid corneal damage, intraocular hypertension, lens opacity and retinal damage induced by long-term silicone tamponade.

New technique for removal of perfluorocarbon liquid related sticky silicone oil and literature review

AIM:To investigate the safety and efficacy of sticky silicone oil(SSO)removal using a 22-gauge vein detained needle and inner limiting membrane(ILM)wrap-and-peel technique.METHODS:This retrospective consecutive case series reviewed the records of patients with a history of retinal detachment who had received silicone oil and perfluorocarbon liquid(PFCL)as intraocular tamponades.Patients were included in the analysis if they exhibited SSO remnants during silicone oil removal.The aspiration of most of the SSO remnants was performed by a 22-gauge vein detained needle.The small amounts of droplets adhered to the macula and epi-macular membrane were subsequently removed by the ILM warp-and-peel technique.The anatomical and functional outcomes,and postoperative complications were recorded.In vitro experiments were performed to simulate the formation of SSO remnants in four groups.RESULTS:Of 711 patients who underwent silicone oil removal during the study period,9 patients exhibited SSO remnants and underwent follow-up for at least 3mo.Seven eyes(78%)underwent the ILM wrap-and-peel technique to completely remove small droplets of SSO that were glued to the macula and epi-macular membrane.No obvious complications occurred.Postoperative optical coherence tomography revealed normal retinal structure in all patients.In vitro analyses showed that balanced salt solution and prolonged vibration(for 1wk)had the strongest effects on silicone oil and PFCL compound opacities.CONCLUSION:SSO remnants could be removed in an intact manner and without complications,using a vein detained needle-assisted and ILM wrap-and-peel technique.The findings suggest that PFCL and infusion fluid should be completely removed before silicone oil injection to prevent SSO formation.

Intracameral anti-VEGF injection for advanced neovascular glaucoma after vitrectomy with silicone oil tamponade

AIM: To evaluate the effect of intracameral injection of conbercept for the treatment of advanced neovascular glaucoma(NVG) after vitrectomy with silicone oil tamponade.METHODS: Conbercept 0.5 mg/0.05 m L was injected into the anterior chamber of 5 eyes, which had developed advanced NVG after vitrectomy with silicone oil tamponade. Then, trabeculectomy with mitomycin C and pan-retinal photocoagulation(PRP) or extra-PRP were conducted within 2 d. The follow-up time was 6 mo. Best-corrected visual acuity(BCVA), intraocular pressure(IOP), neovascularization of iris(NVI) were recorded before and after treatment.RESULTS: Within 2 d after injection, IOP control, and NVI regression were optimal for trabeculectomy. Hyphema occurred in one eye in the process of injection. But none of them present hyphema after trabeculectomy. At the end of follow-up time, all eyes had improved BCVA, well-controlled IOP, and completely regressed NVI. CONCLUSION: Intracameral injection of conbercept is safe and effective in the treatment of patients with advanced NVG after vitrectomy with silicone oil tamponade. Within 2 d after injection is the optimal time window for trabeculectomy, which can maximally reduce the risk of perioperative hyphema.

A modified approach to actively remove high viscosity silicone oil through 23-gauge cannula

AIM:To report a simple approach to actively remove high viscosity silicone oil through a 23-gauge cannula via pars plana.METHODS:Forty-eight eyes of 48 patients underwent silicone oil(5700 centistokes) removal(SOR) were enrolled.A section of blood transfusion set was prepared to connect a standard 23-gauge cannula and vitrectomy machine.Silicone oil was removed with suction of500-mm Hg vacuum through the cannula.Main outcome measures were SOR duration,number of sutured sites,intraocular pressure(IOP),best-corrected visual acuity(BCVA),and complications.RESULTS:Silicone oil was successfully removed in all cases.The mean SOR time was 5.70±0.85 min.Nine eyes(18.75%) needed suture partial sclerotomies.No intraoperative complications were noted.Transient hypotony(≤8 mm Hg) was seen in 3 eyes(6.25%) on postoperative day 1,but all resolved within 1wk.Retinal reattachment was achieved in all cases and no other postoperative complications were noted during 3-month following-up.BCVA at the final visit improved or stabilized in all patients comparing to the preoperative level.CONCLUSION:Active removal of high viscosity silicone oil through a 23-gauge instrument cannula jointed with blood transfusion set is a practical and reliable technique when considering two sides of efficacy and safety.

Analysis of the rates of emulsification in intraocular silicone oil tamponades of differing viscosities

AIM:To investigate the rates of emulsification in silicone oil(SO)tamponades of differing viscosities used during pars plana vitrectomy(PPV)in the treatment of complicated vitreoretinal diseases.METHODS:This study was a prospective randomized clinical trial.Totally 290 cases with greater likelihoods of secondary detachment were included and randomly grouped into either Siluron 2000(n=143)or Siluron 5000(n=147)SO tamponades with 23-gauge PPV.Patient followups and data analyses were conducted 1,3,6,and 12 mo post-surgery.RESULTS:The time of the SO emulsification ranged from 1 to 17 mo,with a mean of 7.3±4.2 mo.The Siluron 5000 group showed a slower emulsification rate in comparison to the Siluron 2000 group.The Siluron 2000 group took a shorter time to show signs of emulsification,necessitating earlier SO removal.However,there were no significant differences in the occurrence of complications,including secondary retinal detachment,cataract,corneal abnormality,high intraocular pressure and hypotony.CONCLUSION:The Siluron 2000 SO tamponade shows a faster rate of emulsification than the Siluron 5000 SO,necessitating earlier removal.Both groups show similar results in terms of anatomical success and visual acuity outcome,and there is no significant difference between the SOs regarding the occurrence of complications.

Outcomes and predictors of vitrectomy and silicone oil tamponade in retinal detachments complicated by proliferative vitreoretinopathy

AIM:To evaluate outcomes and determine factors influencing the outcomes of vitrectomy with silicone oil(SO)endotamponade for the management of rhegmatogenous retinal detachment(RRD)complicated by advanced proliferative vitreoretinopathy(PVR).METHODS:This is a retrospective,interventional case series of eyes with PVR grade C associated RRD with or without prior surgery that underwent vitreoretinal surgery and SO tamponade.Eyes with a minimum follow-up of 6mo after SO extraction were included.Eyes were classified into three PVR subgroups according to severity and extension of proliferation.The influence of several preoperative,intraoperative and postoperative factors upon the functional and anatomical outcomes was assessed using multivariate logistic regression analysis.RESULTS:A hundred and one eyes of 101 patients that met the inclusion criteria were studied.Seventy-five of 101 eyes(74.3%)had successful retinal reattachment after one operation.Increased aqueous cell and flare at the first week exam had a statistically significant association with redetachment,recurrent membrane proliferation and keratopathy.Visual acuity improvement was significantly associated with faint postoperative aqueous inflammation values,primary vitrectomy and PVR outside of the posterior pole.CONCLUSION:Although encouraging anatomical and functional outcomes are achieved after vitrectomy and SO tamponade in eyes with RRD complicated by PVR,an increase in aqueous flare or cells at the first week follow-up is most likely to result in postoperative late complications.Primary vitrectomy,PVR associated with minimal posterior pole extension and absent to mild postoperative aqueous inflammation are associated with improved post-operative final visual acuity.

Comparison of outcomes of idiopathic macular holes treated by vitrectomy with air or silicone oil tamponade based on the hole size

AIM:To compare the efficacy of vitrectomy combined with air or silicone oil in the treatment of idiopathic macular hole(IMH).METHODS:According to the results of high-definition optical coherence tomography(HD-OCT),75 cases(75 eyes)of IMH in stage II-IV(Gass stage)in the General Hospital of Chinese PLA from January 2017 to December 2019 were collected for this retrospective study.The best corrected visual acuity(BCVA)and minimum diameter of IMH(MMHD)were measured.Eyes underwent vitrectomy combined with internal limiting membrane peeling operation,and were divided into disinfection air group(30 eyes)and silicone oil group(45 eyes)according to the intraocular tamponade.For MMHD≤400μm(MMHD1),there were 23 eyes in air group and 16 eyes in silicone oil group.For MMHD2>400μm(MMHD2),there were 7 eyes in air group and 29 eyes in silicone oil group.One month after surgery,the closure rates of IMH and BCVA were compared and analyzed.According to HD-OCT,the closure shape was graded with A(bridge closure)and B(good closure).RESULTS:The closure rates of air group and silicone oil group were 86.67%and 95.56%respectively with no significant difference(P>0.05);For MMHD1,those of air group and silicone oil group were 95.65%and 100%respectively with no significant difference(P>0.05);For MMHD2,those of air group and silicone oil group were 57.14%and 93.10%respectively,and those of the silicone oil group were higher than the air group(P<0.05).There was no significant difference in the closure shape grade between MMHD1 air group and silicone oil group(P>0.05).The proportion of Grade B in MMHD2 silicone oil group was higher than that in the air group(P<0.05).BCVA of each group after operation was better than that before operation,and there was no significant difference between air group and silicone oil group.While among them,MMHD1 air group was better than silicone oil group(P<0.05),and there was no significant difference between MMHD2 air group and silicone oil group(P>0.05).CONCLUSION:For smaller IMH(≤400μm),the efficacy of vitrectomy combined with air should be considered better than silicone oil;for larger IMH(>400μm),the efficacy of silicone oil may be better than air.

Long-term follow-up of cataract surgery in eyes filled with silicone oil

AIM:To evaluate the refractive and long-term outcome of eyes filled with silicone oil(SO)undergoing phacoemulsification cataract surgery(PCS).METHODS:This retrospective study evaluated patients with SO tamponade who were scheduled for PCS.RESULTS:Subjects(n=26)were followed for 29.5±13.9 mo after cataract surgery.The median spherical equivalent refraction(SER)was+5.3 D[interquartile range(IQR)+2.9 to+6.7]before PCS,and+3.4 D(IQR+2.0 to+4.4)after PCS.Within the follow-up period retinal reattachment after SO removal was achieved in 15 out of 26 eyes(57.7%).In 13 eyes assessment of refraction after SO-removal was possible,and showed a myopic shift of-4.6 D(IQR-2.9 to-7.3)in the SER.After SO removal,5 of the 13 eyes(38.5%)were within±1.0 D of the target refraction,while 9 out of the 13 eyes(69.2%)were within±2.0 D.CONCLUSION:In our study,the refraction after PCS for eyes filled with SO manifested low predictability,as did the myopic shift following SO removal.A significant percentage of the eyes that underwent SO administration required a long-term tamponade.

Evaluation of macular vessel density changes after vitrectomy with silicone oil tamponade in patients with rhegmatogenous retinal detachment

AIM:To evaluate macular microvasculature changes in eyes after pars plana vitrectomy(PPV)and intraocular silicone oil(SO)tamponade for macula-off rhegmatogenous retinal detachment(RRD)using optical coherence tomography angiography(OCTA).METHODS:Totally 19 eyes(19 patients)with maculaoff RRD who underwent PPV and intraocular SO tamponade were retrospectively reviewed.The parafoveal superficial capillary plexus(SCP)vessel density(VD),deep capillary plexus(DCP)VD,choriocapillaris plexus(CCP)VD,and foveal macular thickness were evaluated using OCTA throughout 16 wk postoperatively.The values of healthy fellow eyes were used as control.RESULTS:The parafoveal SCP,DCP,and CCP VDs were significant increased over time in RRD eyes during the 12 wk postoperatively,then decreased at 16 wk postoperatively(all P<0.01).The ratios of RRD eyes and fellow healthy eyes(r/f ratios)of the SCP and DCP VDs were lower than those of the CCP VD postoperatively(all P<0.05).There were not significant differences in the r/f ratios between SCP and DCP VDs postoperatively(all P>0.05).CONCLUSION:The parafoveal SCP,DCP,and CCP VDs gradually recover over time after PPV surgery with SO tamponade.Long-time SO tamponade might decrease postoperative macular VDs.Compared to parafoveal CCP VD,the parafoveal SCP and DCP VDs were more vulnerable in RRD eyes postoperatively.

A decrease in macular microvascular perfusion after retinal detachment repair with silicone oil

AIM:To observe whether silicone oil(SO)tamponade could decrease macular perfusion after retinal detachment repair.METHODS:A prospective observational case-control study.Patients diagnosed with primary macular off rhegmatogenous retinal detachment undergoing successful retinal repair surgery with vitrectomy were strictly selected.Optical coherence tomography angiography findings were compared between SO and air tamponade groups.Two postoperative visiting points were set(1 and 3 mo).RESULTS:Totally 29 patients(29 eyes)were enrolled.Twenty cases had SO tamponade while 9 cases were with air tamponade.At the first visiting point,superficial parafoveal vessel density(PFSVD)significantly decreased in the SO group(P=0.0403),especially in the superior quadrant or superior-hemi area(P=0.0089,0.0426,respectively).Parafoveal deep vessel density(PFDVD)had no difference between the two groups.At the second visiting point,all quadrants of PFSVD reduced significantly in the SO group(P=0.0256,0.0001,0.0031,<0.0001 in temporal,superior,nasal,and inferior area,respectively),but PFDVD remained no different.In the air group,all areas of PFSVD showed significantly improving from the first visit to the second one(P=0.0324,0.0001,0.0371,0.0026,in temporal,superior,nasal,and inferior area,respectively);however,almost all quadrants of PFDVD showed no changes during this period.In the SO group,both PFSVD and PFDVD showed no obvious changes between the two visiting points.Besides,parafoveal full retinal thickness in the SO group reduced significantly at both visiting points over the air tamponade,while the foveal avascular zone area showed no difference in the two groups.CONCLUSION:After retinal detachment surgery with vitrectomy and SO tamponade,superficial macular perfusion and full retinal thickness could decrease obviously when compared to air tamponade.This reduction process could persist throughout the tamponade period.

Destabilising persistent coal froth using silicone oil

Persistent froth is becoming more and more common in coal and mineral flotation plants and presents safety and operational challenges.No effective method has been developed to destabilise persistent froth.As a new initiative,this study examined the structural difference between persistent foam and coal froth,based on which a solution was developed to maximumly destabilise coal froth.Destabilisation test,oscillatory rheology measurement and scanning electron microscopy(SEM) analysis indicated that the coal froth was more stable than the foam due to the formation of thin capillaries and tightly arranged coal particles on bubble surfaces.Although 107 μm silicone oil droplet could completely destabilise the foam at 2 mmol/L concentration,it only destabilised less than 50% coal froth even at 6 mmol/L concentration.To maximumly destabilise the coal froth formed by-38 and-20 μm particles,24 and 18 μm silicone oil droplets were required to pass through the thin capillaries and enter the bubble films,respectively.However,smaller silicone oil droplets could not bridge the bubble films to destabilise coal froth and therefore a critical droplet size occurred depending on the size of particles stabilising the froth.

Accuracy of segmented measurement of axial length in ultra-high myopia filled with silicone oil using immersion B-scan ultrasonography

AIM:To evaluate the accuracy of segmented measurement of axial length(AL)in high myopia filled with silicone oil by immersion B-scan ultrasonography(immersion B-scan).METHODS:From June 2016 to June 2020,a total of 67 ultra-high myopia inpatients(67 eyes)who underwent silicone oil removal combined with cataract extraction and intraocular lens(IOL)implantation were retrospectively enrolled.The preoperative axial length(AL)of 31 patients with severe cataract were segmented measured using immersion B-scan(B-scan group)and another 36 patients with mild or moderate cataract were measured using IOLMaster 500(IOLMaster group).The post-operative ALs in two groups were both measured using IOLMaster 500.The IOL power was calculated with Haigis formula.The differences in ALs between pre-and post-surgery,as well as the postoperative refractive spherical equivalent,absolute refractive error,the prediction deviation of postoperative refraction and best corrected visual acuity(BCVA)were compared.RESULTS:The pre-and post-operative ALs were 30.46±1.63 mm(range 28.09-33.51 mm)and 30.42±1.70 mm(range 28.03-33.90 mm)in B-scan group(t=0.644,P=0.542)and 30.51±1.21 mm(range 28.03-33.90 mm)and 30.43±1.27 mm(range 28.54-33.50 mm)in IOLMaster group(t=1.843,P=0.074),respectively.Three months after surgery,BCVA were 0.45±0.13(range 0.3-0.9)and 0.44±0.20(range 0.2-1.0)in B-scan and IOLMaster group respectively(t=0.086,P=0.932).There was no significant difference of the postoperative spherical equivalent(-3.11±0.65 D vs-3.21±0.51 D,t=0.671,P=0.505)and the absolute refractive error(0.589±0.340 vs 0.470±0.245 D,t=1.615,P=0.112)between two groups.In B-scan group,absolute refractive error within±0.50 D was found in 18 eyes(58.1%),within±1.00 D in 26 eyes(83.9%),and within±1.50 D in 31 eyes(100%).In IOLMaster group,absolute refractive error within±0.50 D was found in 23 eyes(63.9%),within±1.00 D in 34 eyes(94.4%),and within±1.50 D in 36 eyes(Z=0.757,P=0.449).CONCLUSION:The segmented measurement of ALs by immersion B-scan shows comparable measurement accuracy with that of IOLMaster 500 in ultra-high myopia patients with severe cataract secondary to silicone oil filling and can obtain an ideal postoperative refractive state.

Preoperative laser reduces silicone oil use in primary diabetic vitrectomy

AIM: To identify the predictive factors and laser photocoagulation associated with the use of silicone oil as endotamponade during primary diabetic vitrectomy. METHODS: The medical and surgical records of 690 patients(798 eyes) who underwent primary diabetic vitrectomy at a tertiary eye hospital in China from January 2018 to December 2018 were reviewed in this retrospective cohort study. The patients’ baseline characteristics and preoperative treatments were recorded. The binary Logistic regression model was used to evaluate the risk factors for the use of silicone oil as endotamponade agent during primary vitrectomy for proliferative diabetic retinopathy(PDR)-related complications.RESULTS: Among 690 patients with mean age of 52.1±10.5 y(range: 18-85 y), 299/690(43.3%) were female. The 31.6% of the eyes received preoperative laser treatment, and 72.4% of the eyes received preoperative anti-VEGF adjuvant therapy. Non-clearing vitreous haemorrhage(VH) alone or combined with retinal detachment was the main surgical indication(89.5%) for primary vitrectomy. Silicone oil was used as endotamponade in 313(39.2%) eyes. Lack of preoperative laser treatment [odds ratio(OR) 0.66, 95% confidence interval(CI): 0.48-0.92;P=0.015] and older age(OR 0.96, 95%CI: 0.95-0.98;P<0.001) were predictors of silicone oil tamponade during primary vitrectomy for PDR. CONCLUSION: The lack of preoperative laser treatment is a significant predictor of silicone oil tamponade during primary vitrectomy for PDR. However, the severity of PDR relevant to silicone oil use should be further evaluated.

Structural evolution of silicone oil liquid exposed to Ar plasma

Structure properties of silicone oil serving as a liquid substrate exposed to Ar plasma are investigated in this paper.Under the action of energetic Ar ions,the surface of silicone oil liquid substrate exhibits a branch-like fractal aggregation structure,which is related to the structure evolution of silicone oil liquid from Si-O chain to Si-O network.The radicals from the dissociation of silicone oil molecule into the Ar plasma turns the plasma into a reactive environment.Therefore,the structural evolution of silicone oil liquid substrate and the reactive radicals in the plasma space become possible factors to affect the aggregation of nanoparticles and also the structures and the compositions of nanoparticles.

Clinical effect of peripheral capsule preservation in eyes with silicone oil tamponade

BACKGROUND At present,silicone oil has been widely used in vitrectomy to deal with complex fundus diseases.Usually,cataract extraction is combined with vitrectomy.However,reducing the complications of silicone oil tamponade and facilitating the secondary implantation of intraocular lens(IOL)are still an urgent problem.AIM To evaluate the clinical effect of vitrectomy combined with peripheral capsule preservation(PCP)in eyes with silicone oil tamponade.METHODS This single-center retrospective analysis included 70 patients(73 eyes)who underwent vitrectomy and silicone oil tamponade combined with cataract surgery(stage I)between January 2015 and July 2019.All patients underwent selective reoperation for silicone oil extraction and IOL implantation(stage II)more than 3 mo after stage I.These patients were divided into three groups according to the different lens capsule preservation methods:28 patients(31 eyes)in a whole capsule preserved(WCP)group,17(17 eyes)in a capsule absent(CA)group,and 25(25 eyes)in a peripheral capsule preserved(PCP)group.Intraocular pressure(IOP),best-corrected visual acuity,surgery time,and other complications were recorded at each time point(1 d,1 wk,and 1 mo after stages I and II).RESULTS The IOP values were 14.9±8.2 mmHg in the WCP group,20.3±13.0 mmHg in the CA group,and 14.2±9.7 mmHg in the PCP group(P<0.05)at 1 mo after stage I operation.Five eyes had IOP higher than 30 mmHg,and one eye in the WCP group appeared to have silicone oil entering the anterior chamber.There was no significant difference in IOP among the three groups at any other time point(P>0.05).With IOL implantation,visual acuity improved significantly compared to stage I.The incidence rate of posterior capsule opacity was higher in the WCP group than in the other groups(P<0.001).In the CA group,IOL deviation due to suture relaxation occurred in one case.There was no significant difference in the surgery time among the three groups in stage I(P=0.618).In stage II,the surgery time of the PCP group and WCP group was significantly shorter than that of the AC group(P=0.031).CONCLUSION Preservation of the peripheral capsule in vitrectomy combined with lens removal is a better option.This method has significant advantages in reducing intraoperative and postoperative complications.

Study on Application of the Silicone Oil in the Reattachment of Complicated Retinal Detachment

Sixty eyes with complicated retinal detachment were treatedby vitrectomy combined with silicone oil tamponade (27 eyes of PMR gradeD,15 eyes of giant retinal tears with posterior flat folded-over,13 eyes ofposterior or macular hole,5 eyes of traumatic PVR).After 3-24 monthsfollow-up,the study showed retinal anatomic reattachment in 48 eyes inwhich the visual acuity of 32 eyes was 0.05 or better.The authorsconsider that vitrectomy and peeling make the silicone oil tamponadeperfect the vitreous surgery an...