Silicone oil insulation effects on flash electroretinogram and visual evoked potential in patients with retinal detachment / Efectos del aislamiento del aceite de silicona sobre el electrorretinograma flash y el potencial evocado visual en pacientes con desprendimiento de retina

Background: Silicone oil is used as endotamponade following vitreoretinal surgery to maintain the retina reattached when indicated. This study investigates the hypothesis that silicone oil causes insulation effects on the retina by affecting its response to light. Methods: Electrophysiological responses to a flash stimulus were recorded using full-field electroretinography (ERG) and visual evoked potentials (VEP). Recordings were performed in 9 patients who underwent surgery for retinal detachment, before (1–2 days) and after (2–3 weeks) silicone oil removal (SOR) in both the study and the control eye. Flash ERG and VEP recordings were performed according to the ISCEV standard protocol. Results: Statistically significant differences were found in the study eye in the amplitudes of the ERG responses and their corresponding ratios, i.e. the amplitude after SOR over the amplitude before SOR, in all conditions tested. No differences were observed in the control eye. The mean ratio of photopic ERG response was 3.4 ± 2.4 for the study and 1.0 ± 0.3 for the control eye (p<0.001). The mean ratio of ERG flicker response was 3.1 ± 2.4 and 1.0 ± 0.3, respectively (p = 0.003). Scotopic flash ERG ratio was 5.0 ± 4.4 for the study and 1.3 ± 0.6 for the control eye (p = 0.012). No differences were observed for the amplitude and latency of flash VEP response after SOR. Conclusions: Silicone oil causes a reduction in flash ERG responses; no effect was found on flash VEP responses. ERGs in eyes filled with silicone oil should not be considered representative of retinal functionality, in contrast to VEPs, which are not affected by silicone oil presence.(AU)

[Translated article] Syringes for intraocular administration: A systematic review.

OBJECTIVE: The off-label use in clinical practice of non-approved syringes for intravitreal drug administration has resulted in the detection of silicone oil drops in the vitreous of some patients. This situation derives from the lack of approved syringes for intraocular use in the Spanish market. The aim of this work is to review the use of syringes for intraocular administration, as well as to search for alternatives that meet the legal requirements for these unmet needs. METHOD: A systematic review was performed following the PRISMA 2020 guidelines by searching PubMed with the descriptors: (silicone) AND (syringes) AND ((intraocular) OR (intravitreal)) and filtering all existing publications from January 2006 to December 2023, including all those articles dealing with silicone oil release in intravitreal injections and analysing the possible consequences. RESULTS: Sixty-eight results were found, 23 of which were excluded because they did not deal with the subject under study, leaving a total of 45 articles for the systematic review. These were classified according to the conclusions obtained in 4 groups: the adverse reactions produced by silicone; the administration technique; the physicochemical aspects of silicone release; and the characteristics of the medical device. After reviewing the current manufacturers and technical data sheets of commercialised syringes, the existing syringes for this use have been collected, finding 2 that will probably be commercialised in Spain at the beginning of 2024: Zero Residual™ 0.2 ml SiO-free and VitreJect® Ophthalmic. CONCLUSIONS: From the results obtained, it can be interpreted that the use of syringes and needles with silicone for intravitreal use is a concern for health professionals due to the implications and consequences that may arise in patients, the most important being adverse reactions, so it is necessary to have silicone-free syringes on the market that are specific for intraocular use. Safety and legality in the use of intraocular syringes and needles is essential to guarantee ocular integrity and patient health.

Retrospective case series of high-density silicone oil (Oxane HD) in severe proliferative vitreorretinal retinal detachment patients.

BACKGROUND: Describe complications and clinical outcomes of heavy silicone oil (HSO) Oxane HD® use as an alternative to overcome the challenges of performing vitrectomy to treat tractional and rhegmatogenous retinal detachments with proliferative vitreoretinopathy (PVR). METHODS: A retrospective, observational study was performed on patients from one center from August 2014 to Aug 2023. It was included patients who underwent surgery using HSO Oxane HD® to treat rhegmatogenous retinal detachment with PVR or mixed tractional and rhegmatogenous diabetic retinal detachment. Severely ill patients who could not attend to follow up were excluded. The primary outcome was successful retinal attachment at first postoperative month. A descriptive analysis was performed. RESULTS: Among the 31 patients, 29 (93.5%) underwent surgeries due to rhegmatogenous retinal detachment and two (6.5%) for diabetic retinal detachment. The primary anatomic success was achieved in 27 (87.1%) patients. At the final visit, 17 (56.6%) had vision better than 20/400 (range, 20/30 to light perception). The vision was stable or improved in 22 (76.8%) patients at the end of follow-up. Nineteen (61.3%) patients required hypotensive eye drops after HSO use and twelve (38.7%) still required hypotensive eye drops at the final follow-up; three (9.7%) patients required additional glaucoma surgeries. CONCLUSIONS: HSO is safe and useful for complex retinal detachments cases specially with inferior tears and PVR. Ocular hypertension is frequent and usually clinically controlled with hypotensive eyedrops. Close postoperatively follow-up is advised due to the ocular complications, particularly elevated intraocular pressure and emulsification.

Management of macula-on giant retinal tear detachments- outcome of pars-plana-vitrectomy with silicone oil versus gas tamponade.

BACKGROUND: To compare the outcome of eyes with a macula-on giant retinal tear (GRT) detachment treated with pars-plana-vitrectomy (PPV) depending on the used endotamponade. METHODS: All consecutive cases with a macula-on GRT-associated rhegmatogenous retinal detachment (RRD) managed with PPV between 2007 and 2022 were retrospectively assessed depending on the selected endotamponade. By reviewing medical charts and surgical protocols the pre- and intraoperative parameters were analysed in detail. The number of vitreoretinal (VR) procedures needed for reattachment, the redetachment rate and the functional outcome were evaluated. Eyes treated with primary silicone oil (SO) tamponade were compared to eyes with primary gas tamponade. Cases with pre-existing conditions affecting outcome e.g. macula-off situation, history of trauma, status after complicated cataract surgery, former VR surgery or proliferative vitreoretinopathy grade C or higher were excluded. RESULTS: Overall, 51 eyes of 45 patients with a macula-on GRT detachment were treated with PPV and SO (n = 32; 63%) or gas (n = 19; 37%) endotamponade in the observed period. Eyes with primary SO tamponade underwent on average 2.3 (SD 0.8) VR procedures and had a redetachment rate of 13% (n = 4). Eyes with gas tamponade showed a higher redetachment rate of 32% (n = 6) with a mean number of 1.6 (SD 1.0) PPV procedures. Postoperative best-corrected visual acuity (BCVA) was significantly better in eyes with primary gas tamponade (mean logMAR BCVA 0.32; SD 0.30) compared to eyes with SO (mean logMAR BCVA 0.60; SD 0.42; p = 0.008). CONCLUSIONS: Surgical management of GRT-associated RRDs is complex. In clinical routine often SO is used as endotamponade. Because of known disadvantages (second procedure necessary for SO removal, unexplained SO-related visual loss, secondary glaucoma, SO emulsification) some VR surgeons prefer a gas tamponade. In our cohort, eyes with a gas compared to SO tamponade showed higher redetachment rates. However, the final postoperative BCVA was significantly better in eyes with gas compared to SO tamponade. TRIAL REGISTRATION: The trial protocol was approved by the local ethics committee on 25th of November 2022 (Ethikkommission der Universität Regensburg, Votum 22-3166-104).

Macular and Optic Disc Perfusion Changes After Silicone Oil Removal Using Optical Coherence Tomography Angiography: A Prospective Study.

AIM: The aim of this study was to prospectively evaluate the changes in macular and optic disc microvascular structures in patients who underwent silicone oil (SO) removal. MATERIALS AND METHODS: A total of 28 patients scheduled for unilateral SO removal were included in the study. Their fellow eyes served as controls. Optical coherence tomography angiography (OCTA) of the retina (6.0 mm) and disc (4.5 mm) was performed one day before SO removal, and then at 1 week and 1, 3, 6, and 12 months postoperatively. All analyses were conducted using the R programming language, with a p-value <0.05 considered statistically significant. RESULTS: After silicone oil removal, statistically significant changes were observed in the flow in the outer retina and radial peripapillary capillary (RPC) density for small and all vessels inside the disc. Statistically significant differences between the intervention and control groups were noted in vessel density in both the superficial and deep capillary plexuses and RPC density for small and all vessels. CONCLUSION: Changes in macular vessel density and radial peripapillary capillary density were observed after SO removal. The latter changes appear to improve after the first postoperative month and continue until the first postoperative year. Notably, these changes were significant between the first postoperative week and 6 and 12 postoperative months (p = 0.0263 and p = 0.021, respectively). Best corrected visual acuity (BCVA) is likely associated with these parameters, indicating that improvement may be observed even one year following SO removal.

Position Adherence in Patients Underwent Pars Plana Vitrectomy with Silicone Oil Tamponade.

Introduction: Position adherence of patients with Pars Plana Vitrectomy with Silicone Oil Tamponade after discharge is of positive significance. However, patients undergoing a day surgery makes the quality of discharge teaching and readiness for hospital discharge is insufficient, which will influence their position adherence at home. Aim: This study aimed to find the correlation of discharge teaching, readiness for hospital discharge, and position adherence in patients who underwent PPV with silicone oil tamponade from the day ward. Methods: This was a cross-sectional survey. One hundred ninety-four patients with day surgery were recruited by convenient sampling from Zhongshan Ophthalmic Center, China. Data were collected using the quality of discharge teaching scale, readiness for hospital discharge scale, and position adherence scale. Results: Patients' education level, residence, poor postoperative vision, ophthalmic surgery history, and quality of discharge teaching are the main factors of readiness for discharge. Only 41(21%) patients had good position adherence, and education level and readiness for discharge are the main factors of position adherence. Discussion: Discharge teaching improves patients' knowledge and competence of self-care and helps patients prepare for the transition from hospital to home, and readiness for hospital discharge significantly influences position adherence after discharge and indirectly plays a vital role in postoperative vision recovery and surgical effect.

Multiple Types Late-Onset Postoperative Retinal Folds following Vitrectomy for Retinal Detachment Repair with Silicone Oil: Morphologic Variability and Optical Coherence Tomography Angiography Features - A Case Report.

Introduction: Retinal folds (RFs) may develop following rhegmatogenous retinal detachment (RRD) repair, though it consists an uncommon complication. Case Presentation: Herein, we present a case of late-onset postoperative outer RFs with aggravating characteristics following vitrectomy with silicone oil (SO) tamponade for RRD repair; early clinical findings, complications, anatomical and functional status during a 12-month follow-up period are described. Retinal imaging by acquiring optical coherence tomography scans and angiograms indicates detailed morphological and angiographic characteristics of the evolution of RFs over time. Our case provides insight into a combination of various types of RFs along with retinal disorganization with appearance in the late postoperative period after RRD repair with SO tamponade. Conclusion: Our aim was to raise awareness of the pathological processes that may be associated with the development and evolution of RFs after successful RRD repair, indicating that it is critical to accurately diagnose the type of RFs and closely monitor their progression in an attempt to provide prognostication for future visual outcomes.

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

AIM: To evaluate scleral buckling (SB) surgery using a non-contact 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.

Impact of duration of silicone oil tamponade on foveal and parafoveal thickness in rhegmatogenous retinal detachment: a retrospective cohort study.

PURPOSE: To detect and analyze the influence of the duration of tamponade with silicone oil on the foveal and parafoveal thickness in cases of rhegmatogenous retinal detachment. METHODS: This is a retrospective cohort study of 64 eyes with rhegmatogenous retinal detachment in one eye who underwent pars plana vitrectomy (PPV) with silicone oil injection during the period between January 2019 and December 2021. The patients were divided into 2 groups. Group A with early removal of the silicone oil after 3-4 months and Group B with late removal of the silicone oil (SOR) after 6-8 months. The 2 groups were compared as regards the central foveal (CFT) and parafoveal (PFT) thickness changes from baseline, just before SOR, and after SOR. Changes in best corrected visual acuity (BCVA), relative risk of severe thinning. It was conducted at Kasr Alainy Hospital. RESULTS: 64 eyes were enrolled in the study. Group A included 36 eyes, and group B included 28 eyes. The mean CFT changed insignificantly from 253 ± 52 µm to 252 ± 48 µm after SOR in group A; while it changed significantly from 211 ± 52 µm to 202 ± 46 µm after SOR in group B. The mean PFT decreased insignificantly from 299 ± 39 µm to 297 ± 40 µm in group A, while it decreased significantly from 284 ± 46 µm to 273 ± 44 µm in group B. Lines of improvement of BCVA were 4.11 ± 1.88 in group A, and 2.00 ± 1.24 in group B. Relative risk of severe foveal thinning after SOR was 14.3, and severe parafoveal thinning was 15.43, in group B compared to group A. CONCLUSION: Longer period of silicone oil tamponade may carry a higher risk for severe foveal and parafoveal thinning after silicone oil removal. TRIAL REGISTRATION: The study was registered at clinical trial.gov under the title of (Duration of silicone oil tamponade on foveal and parafoveal thickness in Rhegmatogenous Retinal Detachment) with an ID NCT05817630 at April 2023 "retrospectively registered".

Emulsification of Silicone Oils: Altering Factors and Possible Complications-A Narrative Review.

Background: Endotamponade of the vitreous body with silicone oil is a common procedure, being the basis of many vitreoretinal surgeries. However, emulsification may happen, which is a clinically relevant adverse event of silicone oil use. Methods: This review provides a thorough analysis of the emulsification process. It focuses on describing factors affecting this event as well as its possible subsequent complications. Results: The viscosity of silicone oil, the duration of emulsification, the status of the lens and many other factors have an influence on the onset and intensity of emulsification. This phenomenon carries several risks for operated eyes such as increased intraocular pressure, keratopathy or structural changes to the retina. Conclusions: The use of modern imaging techniques, especially optical coherence tomography, enables faster detection of the emulsification process. This allows for an adequate clinical response and more accurate follow-up of the patient.

Effect of Amino Silicone Oil-Phosphorylation Hybrid Modification on the Properties of Microcellulose Fibers.

Microcellulose materials are increasingly considered multifunctional candidates for emerging energy applications. Microcellulose fibers (MCF) are a kind of bio-based reinforcement in composites, and their hydrophilic character hinders their wide application in industry. Thus, in the present work, MCF was hybrid-modified by amino silicone oil-phosphorylated to fabricate hydrophobic, thermal stability, and flame-retardant microcellulose fibers for potential application in vehicle engineering. The results showed that the amino silicone oil-phosphorylated (ASOP) hybrid modification could transform the surface property of microcellulose from hydrophilic to hydrophobic and improve the compatibility between MCF and resin matrix. Meanwhile, the ASOP treatment led to the formation of an amino silicone oil film layer on the surface of the microcellulose, which improved the thermal stability of the MCF. Furthermore, the ASOP hybrid modification microcellulose fibers paper (100% microcellulose fibers paper) was transformed from flammable to flame-retardant and showed self-extinguishing behavior after burning under flame for 2 s. The flame-retardant mechanism was attributed to the formation of the char layer in the condensed phase and the production of non-combustible gases in the gaseous phase.

Hydroxyl silicone oil grafting onto a rough thermoplastic polyurethane surface created durable super-hydrophobicity.

Indwelling medical catheters are frequently utilized in medical procedures, but they are highly susceptible to infection, posing a vital challenge for both health workers and patients. In this study, the superhydrophobic micro-nanostructure surface was constructed on the surface of thermoplastic polyurethane (TPU) membrane using heavy calcium carbonate (CaCO3) template. To decrease the surface free energy, hydroxyl silicone oil was grafted onto the surface, forming a super-hydrophobic surface. The water contact angle (WCA) increased from 91.1° to 143 ± 3° when the concentration of heavy calcium CaCO3 was 20% (weight-to-volume (w/v)). However, the increased WCA was unstable and tended to decrease over time. After grafting hydroxyl silicone oil, the WCA rose to 152.05 ± 1.62° and remained consistently high for a period of 30 min. Attenuated total reflection infrared spectroscopy (ATR-FTIR) analysis revealed a chemical crosslinking between silicone oil and the surface of TPU. Furthermore, Scanning electron microscope (SEM) image showed the presence of numerous nanoparticles on the micro surface. Atomic force microscope (AFM) testing indicated a significant improvement in surface roughness. This method of creating a hydrophobic surface demonstrated several advantages, including resistance to cell, bacterial, protein, and platelet adhesion and good biosecurity. Therefore, it holds promising potential for application in the development of TPU-based medical catheters with antibacterial properties.

Refractive outcomes following silicone oil tamponade in vitreoretinal surgery.

PURPOSE: To evaluate the factors influencing the refractive outcomes following silicone oil tamponade (SOT) and silicone oil removal (SOR) in different lens statuses post-vitreoretinal surgery. DESIGN: Retrospective analysis of three different lens statuses. MATERIALS AND METHODS: This was a descriptive study that included 150 eyes of 147 patients who had undergone pars plana vitrectomy with SOT and SOR between January 2017 and June 2021. Demographic profile, spherical equivalent refraction (SER), and its association with clinical features were evaluated with SOT and post-SOR. RESULTS: The mean (±standard deviation [SD]) age was 47 ± 17.8 years, including all three groups. SER was represented in diopters (D). The mean ± SD refraction with SOT in phakic, pseudophakic, and aphakic was 4.28 ± 2.59 D, 2.94 ± 2.58 D, and 3.98 ± 4.82 D. The mean SER post-SOR in phakic, pseudophakic, and aphakic was -2.72 ± 2.03 D, -1.12 ± 1.41 D, and 8.22 ± 3.70 D. The diagnosis of rhegmatogenous retinal detachment (RRD) among 96 eyes (64%) is the common indicator to perform vitreoretinal (VR) surgery. A minority of subjects were managed with retinal lasers before VR surgery (14%). The macula was attached in 100 eyes (67.6%), the belt buckle was done in 37 eyes (24.7%), and the silicone oil viscosity with 1000 centistoke was chosen in 129 eyes (86%). CONCLUSION: SOT was used as a tamponade in VR surgeries irrespective of lens status. The significant predictor for post-SOR refraction in phakic and aphakic is post-SOT refraction. In pseudophakic, gender and diagnosis of RRD are the predictors of SOR refraction.

Syringes for intraocular administration: Systematic review. / Jeringas para administración intraocular: revisión sistemática.

OBJECTIVE: The off-label use in clinical practice of non-approved syringes for intravitreal drug administration has resulted in the detection of silicone oil drops in the vitreous of some patients. This situation derives from the lack of approved syringes for intraocular use in the Spanish market. The aim of this work is to review the use of syringes for intraocular administration, as well as to search for alternatives that meet the legal requirements for these unmet needs. METHOD: A systematic review was performed following the PRISMA 2020 Guidelines by searching PubMed with the descriptors: "silicone" AND "syringes" AND ("intraocular" OR "intravitreal") and filtering all existing publications from January 2006 to December 2023, including all those articles dealing with silicone oil release in intravitreal injections and analysing the possible consequences. RESULTS: Sixty-eight results were found, 23 of which were excluded because they did not deal with the subject under study, leaving a total of 45 articles for the systematic review. These were classified according to the conclusions obtained in 4 groups: the adverse reactions produced by silicone, the administration technique, the physicochemical aspects of silicone release, and the characteristics of the medical device. After reviewing the current manufacturers and technical data sheets of commercialized syringes, the existing syringes for this use have been collected, finding two that will probably be commercialized in Spain at the beginning of 2024: Zero Residual™ 0.2 ml SiO-free and VitreJect® Ophthalmic. CONCLUSIONS: From the results obtained, it can be interpreted that the use of syringes and needles with silicone for intravitreal use is a concern for health professionals due to the implications and consequences that may arise in patients, the most important being adverse reactions, so it is necessary to have silicone-free syringes on the market that are specific for intraocular use. Safety and legality in the use of intraocular syringes and needles is essential to guarantee ocular integrity and patient health.

Effect of silicone oil versus gas tamponade on macular layer microstructure after pars plana vitrectomy for macula on rhegmatogenous retinal detachment.

PURPOSE: To analyze structural changes in the macular retinal layers and sub-foveal choroidal thickness (SFCT) in eyes after macula-on rhegmatogenous retinal detachment (RRD) repair by pars plana vitrectomy with either silicone oil (SO) or gas tamponade, and the effect of these changes on visual acuity. PATIENTS AND METHODS: Retrospective study which included 26 eyes in the SO Group and 32 in the Gas Group. Optical coherence tomography (OCT) scans of the affected eyes were obtained before surgery, and 3 months after PPV in the Gas Group, and during silicone oil in situ and 3 months after SO removal, in the SO Group. Qualitative assessment of photoreceptor layer and foveal contour, along with quantitative assessment of macular retinal thickness and SFCT was performed. Postoperative OCT macular microstructural changes were recorded and correlated to corrected distance visual acuity (CDVA). Intraocular pressure (IOP) was measured preoperative and at 3 months post operative. RESULTS: There was a 2-line loss (from 20/28 preoperatively to 20/40 at final follow-up) of CDVA in the SO Group (p=0.051), while there was no statistically significant change in CDVA in the Gas Group (p=0.786). There was no significant correlation between CDVA loss and duration of silicon tamponade (r=-0.031, p=0.893). There was a statistically significant increase in IOP from its baseline to final follow-up of 0.7 mmHg in the SO Group (p=0.023) while there was no statistically significant change in IOP in the Gas Group. During silicone oil tamponade, there was approximately 11% and 5% of retinal and sub-foveal choroidal thinning respectively, which was moderately resolved following silicone oil removal. 20% (5/24) of eyes in the SO Group had qualitative flattening of foveal contour during SO tamponade that resolved after SO removal. CONCLUSION: Thinning of the macula was noticed after macula-on RRD repair with SO tamponade. Such thinning was only partially reversible after the removal of SO.

One-step synthesis of functional slippery lubricated coating with substrate independence, anti-fouling property, fog collection, corrosion resistance, and icephobicity.

Ranging from industrial facilities to residential infrastructure, functional surfaces encompassing functionalities such as anti-fouling, fog collection, anti-corrosion, and anti-icing play a critical role in the daily lives of humans, but creating these surfaces is elusive. Bionic dewetting and liquid-infused surfaces have inspired the exploitation of functional surfaces. However, practical applications of these existing surfaces remain challenging because of their inherent shortcomings. In this study, we propose a novel functional slippery lubricated coating (FSLC) based on a simple blend of polysilazane (PSZ), silicone oil, and nano silica. This simple, nonfluorine based, and low-cost protocol promotes not only hierarchical micro-nano structure but also favorable surface chemistry, which facilitates robust silicone oil adhesion and excellent slippery properties (sliding angle: ∼1.6°) on various solid materials without extra processing or redundant treatments. The highly integrated competence of FSLC, characterized by robustness, durability, strong adhesion to substrates, and the ability for large-area preparation, render them ideal for practical production and application. The proposed FSLC holds outstanding application potentials for anti-fouling, self-cleaning, fog collection, anti-corrosion, and anti-icing functionalities.

Effect of Methyl Hydro-Silicone Oil Content and Aging Time on Compression Modulus and Breakdown Strength of Additional Liquid Silicone Rubber Gel.

The performance of silicone rubber gel elastomers is affected by the composition and structure of the crosslinker. In this work, a two-component addition liquid silicone rubber gel material was developed, and the effects of the contents of two methyl hydro-silicone oils on the compression modulus and breakdown strength of the silicone rubber gel insulating material, as well as the performance change after hot air aging at different times (24 h, 48 h, 72 h, 96 h, 120 h, 144 h, 168 h), were studied. The results showed that the breakdown strength and compression modulus exhibited an upward trend with the increase in the hydrogen silicone oil content. The best performance was achieved in the silicone rubber gel with Si-H:Si-Vi = 1.4:1. Moreover, with the increase in aging time, the breakdown strength decreased and the compression modulus increased.

Risk Factors and Management of Intraocular Pressure Elevation After Vitrectomy Combined with Silicone Oil Tamponade.

Silicone oil has emerged as the common option for intraocular tamponade during complicated retina vitrectomy. However, the postoperative elevation of intraocular pressure (IOP), influenced by numerous factors, remains a significant and frequently encountered complication that poses a potential threat to vision. Extensive research has been conducted to investigate the risk factors associated with elevated IOP following silicone oil tamponade, including silicone oil viscosity, preoperative high IOP, diabetes, and lens status. This comprehensive review aims to gather and summarize the current research findings regarding the risk factors contributing to IOP elevation following silicone oil tamponade, as well as the optimal management strategies for secondary glaucoma. The analysis includes the physicochemical properties of silicone oil, preoperative and intraoperative risk factors, and the effective management of secondary glaucoma. Enhancing our understanding of the primary factors associated with silicone oil-induced IOP elevation will facilitate the guidance of timely and appropriate interventions.

Long-Term Stable Superlubricity Coatings Enabled by the Interaction between the Polydimethylsiloxane Brush and Silicone Oil.

Recently, materials with superlubricity captured widespread attention on account of their great potential in energy savings and environmental protection. However, certain issues still remain to be solved for the traditional materials, such as the dependence on strict conditions and an unstable superlubricity state. Herein, a long-term stable superlubricity coating was prepared using a low-cost and simple method via an epoxy-based coating with polydimethylsiloxane (PDMS) brushes under silicone oil (SO) lubrication conditions. Compared with the pure epoxy resin matrix, the friction coefficient and wear track width of the superlubricity coating with the optimal amount of 6 wt % PDMS are reduced to 0.006 and 50.9 µm (reduced by 10-fold and 5.6-fold decrease, respectively). In addition, the coating can maintain a stable superlubricity state during a 5 h tribological test. The superlubricity of the coating results from the synergistic lubrication effect of the PDMS brush and SO. First, PDMS brushes with high-stretched conformation due to the swelling effect of the SO can significantly reduce friction. Second, a stable oil film is generated between the contact surfaces, which significantly improves the frictional performance. Moreover, the PDMS incorporated into the coating matrix, along with oil-swelling PDMS brushes on the surface, is highly beneficial for enhancing corrosion resistance of the epoxy resin matrix. Such an epoxy-based coating with long-term stable superlubricity is considered as a potential lubricating and protective surface for tribological components for long-term service.

Early recurrence of macular schisis in X-linked retinoschisis treated with vitrectomy for rhegmatogenous retinal detachment under silicone oil: case report and brief literature review.

X-linked retinoschisis (XLRS) is an inherited retinal degeneration affecting males, characterized by splitting of the retinal layers. We herein present the outcomes of surgical treatment in a case of XLRS complicated by rhegmatogenous retinal detachment (RRD). A 22-year-old male presented to the emergency department due to decreased visual acuity and visual field defect in his left eye Oculus Sinister (OS) of 1 week duration. The patient reported an early onset retinal degeneration and decreased visual acuity in both eyes since childhood in his past ocular history. Upon presentation, best corrected visual acuity (BCVA) was 6/30 on the right eye Oculus Dexter (OD) and 6/120 OS. Fundus examination revealed areas of peripheral retinal schisis, and the characteristic spoke wheel pattern on the macula of both eyes. In OS, a temporal RRD involving the macula was identified. The patient underwent surgical treatment with pars plana vitrectomy with internal limiting membrane (ILM) peeling, endolaser, and silicone oil (SO) tamponade. BCVA in OS improved to 6/60 and schistic cavities resolution was observed in the immediate postoperative period. The patient's BCVA further improved to 6/19 at 1 month, as foveal anatomy showed relative improvement. However, there was a rapid reappearance of schisis spaces in the macular area at this point, which was also followed by progressive deterioration of foveal schisis by 3 months post-operatively. The resorption and recurrence of lamellar macular schisis changes after ILM peel and presence of SO, highlights that although XLRS findings can temporarily improve upon surgical intervention, the pathogenetic mechanisms contributing to disease phenotype remain to be elucidated.