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Purpose: This study aims to investigate the risk factors for postoperative vitreous cavity opacification following pars plana silicone oil removal and its impact on prognostic visual acuity. Methods: A retrospective case–control study was conducted. A total of 66 eyes from 66 patients were enrolled in the study. On the first postoperative day, all patients underwent a scanning laser ophthalmoscopy to assess the turbidity of the vitreous cavity. 42.42% (28/66) were categorized as Grade 0, 36% (24/66) as Grade I, and 21% (14/66) as Grade II, based on the visibility of posterior pole blood vessels. Ordered multiple classification logistic regression analysis was employed to investigate the impact of surgical and baseline factors on the occurrence and severity of vitreous cavity opacification. Results: The presence of high myopia and the intraoperative combination of epiretinal membrane peeling exhibited significant correlations with the development of postoperative vitreous cavity opacification (OR = 3.424, 95% CI 2.326–31.643, P = 0.023; OR = 3.612, 95% CI 1.263–14.676, P = 0.031, respectively). The best corrected visual acuity (BCVA) on the first day post-surgery was significantly reduced across all degrees of opacification compared to the preoperative level (p < 0.001). However, no significant difference in BCVA was detected between the preoperative period, one-week post-operation, and the last follow-up (P > 0.05). Conclusion: High myopia and intraoperative epiretinal membrane peeling may be associated with the development of more severe vitreous cavity opacity following silicone oil removal. This opacity generally resolves within one week post-surgery and does not appear to increase the risk of retinal re-detachment. [ABSTRACT FROM AUTHOR]

Purpose: To clarify the definition, prevalence and classification of different types of unexplained vision loss associated with silicone oil (SO) endotamponades (SO in situ (SOIS) or after removal of SO (ROSO)) in vitreoretinal surgery and identifying the most specific clinical findings and suggesting possible causes. Methods: Review of the literature regarding randomized clinical trials (RCTs), retrospective case–control, cohort studies and case series evaluating the risk of using SO, published in English between 1994 and 2023, conducting a computer-based search of the following databases: PubMed, Web of Science, Scopus and Embase. The search was supplemented using the Medline option 'Related Articles' and consulting review articles on the topic. Results: Findings from reported clinical examinations in SOIS and ROSO are analyzed and finally different theories regarding the underlying pathophysiology are described. From the clinical point of view, findings have been found in OCT, OCTA, microperimetry and electrophysiological studies. Other clearly identifiable causes of vision loss related to the use of SO are listed and commented as differential diagnosis. Finally, the different physiopathological theories of the two types of causes of unexplained vision have been analyzed. Conclusion: Unexpected vision loss under or after SO tamponade (SOIS and ROSO) is a significant concern which is probably underestimated because it is not a clearly defined and known entity. The most frequently described changes were in the ganglion cell complex but this unexpected vision loss remains a serious and unexplained concern for vitreoretinal surgeons and should be identified by clinicians, addressed by manufacturers and reported to Health Authorities as a serious incident according to the new regulation. [ABSTRACT FROM AUTHOR]

Purpose: We report a case of silicone oil placement after Boston type 1 keratoprosthesis implantation for improvement and maintenance of intraocular pressure in a patient with chronic hypotony secondary to chronic uveitis. Methods: Observational case report. Results: A 54-year-old woman with a history of bilateral chronic panuveitis and subsequent hypotony presented with progressive corneal decompensation and band keratopathy in her better-seeing left eye. Corrected distance visual acuity in her left eye declined from count fingers at 39 to hand motion. In an effort to clear the visual axis and stabilize intraocular pressure, implantation of a Boston type 1 keratoprosthesis combined with pars plana vitrectomy and silicone oil injection was performed. Postoperatively, the intraocular pressure improved to the midteens and vision improved to count fingers at 49with a follow-up of 2 years. Conclusion: Pars plana vitrectomy and injection of silicone oil after placement of a Boston type 1 keratoprosthesis can successfully improve and maintain intraocular pressure in eyes affected by chronic uveitis with ciliary body atrophy and chronic hypotony. This strategy effectively reverses such problems as hypotony maculopathy, disk swelling, scleral infolding, and corneal failure. [ABSTRACT FROM AUTHOR]

Organosilicon materials have shown potential as dehydration agents for waterlogged wooden artifacts. These materials can polymerize under normal conditions to form polymers with favorable mechanical strength, antibacterial properties, and aging resistance. However, the insolubility of most organosilicon hindered their penetration into waterlogged wood, which may lead to an unwanted cracking. This study aimed to evaluate the effectiveness of polydimethylsiloxane (PDMS) and hydroxy-terminated polydimethylsiloxane (PDMS-OH) with low viscosity and moderate reactivity for dehydrating waterlogged wooden artifacts from the Nanhai No.1 shipwreck. Four surfactants ((3–aminopropyl) triethoxysilane (APTES), alkyl polyoxyethylene ether (APEO), tri-methylstearylammonium chloride (STAC), and fatty alcohol polyoxyethylene ether (AEO)) and cosurfactant were employed to transform the two kinds of water-repellent silicone oils into eight groups of highly permeable oil-in-water (O/W) emulsions. Under the catalysis of a neutral catalyst, in situ polymerization occurred within the wood cells. Group P2-2 formulated with PDMS-OH and APEO showed the best efficiency in maintaining the dimensions of the wood during dehydration. The dehydrated wood exhibited a natural color and texture with a minimal volume shrinkage rate of 1.89%. The resulting polymer adhered uniformly to the cell walls, effectively reinforcing the wood cell structure. The weight percent gain of the wood was only 218%, and the pores of the cell lumen were well maintained for future retreatment. This method effectively controlled the sol–gel reaction process of the organosilicon and prevented damage to the wooden artifact during the dehydration process. Moreover, the dehydrated wood samples only experienced a low weight gain of 17% at 95% relative humidity (RH), indicating their great environmental stability. [ABSTRACT FROM AUTHOR]

AbstractPurposeMethodsResultsConclusionSilicone oil (SO) has been used as a vitreous tamponade for decades. Surgical complications such as glaucoma, cataract, or emulsification are well known. Despite that, increasing case reports of unexplained visual loss after SO removal is concerning because there is no treatment available. This article describes practical complications related to SO use and advantages/disadvantages for consideration regarding the choice of a vitreous substitute in practice.A literature review was conducted for publications related to silicone oil, heavy silicone oil, and vitreous substitutes.This article summarizes the SO chemical and physical properties including both SO and heavy SO and postoperative complications such as corneal decompensation, glaucoma, hypotony, cataract, optic neuropathy. Surgical complications such as over/underfilling, SO migration/emulsification, sticky SO and proliferative vitreoretinopathy (PVR) simulating epiretinal membranes formation, recurrent retinal detachments, SO unexplained visual loss, and permanent SO, are described. A brief overview on potential vitreous substitutes is presented.The decision to use SO as vitreous substitute in daily practice is based on the severity of retinal diseases and surgeon experience. SO potential complications must not be underestimated. The pursuit of novel safer vitreous substitutes is imperative. [ABSTRACT FROM AUTHOR]

Background: This study aimed to precisely predict the size and silicone oil injection of a foldable capsular vitreous body (FCVB) via computerized three-dimensional (3D) ocular reconstruction in the treatment of severe retinal detachment in China. Methods: The 3D software Unigraphics NX was applied to determine the volume of the inner cavity with 16–30 mm axial length, assigning the anterior and posterior chambers, the FCVB sizes, and the silicone oil injection volume, and modeling the data between the axial length and the FCVB size. In clinical practice, IOL Master was applied to accurately measure the axial length of the contralateral healthy eye to anchor the anterior-posterior and horizontal diameters of the operated eye in horizontal position CT, and compared with the model to recommend the FCVB size and silicone oil amount, and the clinical effect was validated in cases across five hospitals in China. Results: For the axial length of 16–30 mm, the volume of the inner cavity is 1.2 ml-8.4 ml. FCVB size and silicone oil volume were recommended based on this volume of the inner cavity. Of 253 cases, we noted 11 cases implanted with AV-10P and 1.05 ± 0.21 ml of silicone oil, 41 with AV-12P and 1.58 ± 0.18 ml of silicone oil, 163 with AV-13.5P and 2.48 ± 0.29 ml of silicone oil, 31 with AV-15P and 3.57 ± 0.39 ml of silicone oil, and 7 with AV-17P and 5.71 ± 0.81 ml of silicone oil. There was no significant difference in postoperative visual acuity scores compared with preoperative (P = 0.097), postoperative IOP(10.29 ± 0.57mmHg)was slightly higher than preoperative IOP (9.76 ± 0.48 mmHg), but there was still no statistically significant difference between the two comparisons (P = 0.405). Conclusion: Three-dimensional reconstruction prediction is a good solution for eyeballs with obvious individualized changes in severe retinal detachment, and this method helps doctors standardize FCVB size selection and the silicone oil amount for patients. [ABSTRACT FROM AUTHOR]

Background: Cystoid macular edema (CME) can develop following silicone oil placement in complex vitreoretinal surgeries, contributing to poor visual outcomes. In this study, we investigated the clinical and surgical characteristics associated with the development of CME following the use of silicone oil (SO) in pars plana vitrectomy (PPV) surgeries. Methods: We conducted a retrospective chart review of patients who underwent implantation of SO during PPV from 2010 to 2020 by a single surgeon. Patient demographics, type of oil, duration of oil tamponade, retinectomy size, diabetic status, lens status, prior panretinal photocoagulation, visual acuity, and incidence of CME were reviewed. Results: This study included 43 eyes from 40 patients who underwent SO tamponade for retinal detachment (RD) surgery. The mean duration of SO tamponade was 15.7 ± 12.7 months (range: 1–58 months). The most common indication for surgery was diabetic tractional RD (32.7%), followed by traumatic RD (16.3%) and rhegmatogenous RD with proliferative vitreoretinopathy (11.6%). Of the 43 eyes, 18 (41.9%) developed CME for the first time after PPV with SO placement, with 8 (44%) resolving within a year of oil removal. The mean duration for the development of CME was 9 months. A logistic regression model showed that a scleral buckle procedure and poor initial vision were statistically significant factors for predicting the development of CME (ORs: 11.65 and 16.06, respectively). Overall, 91% of the patients had stable or improved vision after surgery. Conclusions: The use of a scleral buckle procedure and poor initial vision are significant factors for predicting CME following silicone oil tamponade in PPV surgeries, with 41.9% of patients developing CME with an average duration of 9 months. Recognizing such factors can lead to early monitoring and prompt management of CME. Meeting presentation: Partial analyses were presented at the ASRS 2020 conference. Clinical trial number: Not applicable. [ABSTRACT FROM AUTHOR]

Khaled Safadi, Yossi Eshel, Jaime Levy, Liran Tiosano, Tareq Jaouni, Samer Khateb Department of Ophthalmology, Hadassah University Medical Center, Faculty of Medicine, the Hebrew University of Jerusalem, Jerusalem, IsraelCorrespondence: Samer Khateb, Department of Ophthalmology, Hadassah University Medical Center, Faculty of Medicine, the Hebrew University of Jerusalem, Jerusalem, 91120, Israel, Email Samer.khateb@mail.huji.ac.ilPurpose: Macular edema is a known complication following complicated retinal detachment repair with silicone oil (SiO) tamponade. Limited previous research has not led to a consensus regarding the safety and efficacy of intra-SiO injections. Consequently, we aim to present our case series study on intra-SiO injections for postoperative macular edema.Methods: A retrospective, single-center, case series study of eight eyes that developed macular edema postoperatively following complicated retinal detachment repair surgery with SiO tamponade, were treated with different forms of intravitreal injections such as steroids or anti-vascular endothelial growth factor (VEGF). The main outcome measures included visual acuity (VA), central subfield macular thickness (CSMT), and the type and number of injections.Results: The mean age (±SD) of the patients was 64.75± 8.9 years. The mean follow-up period (±SD) was 3.1± 2.2 years. The mean (±SD) number of injections was 8.25± 7.24. Mean (±SD) VA (in LogMAR) and CSMT before injections were 1.7± 0.8 and 488± 104 μm, respectively. At the last follow-up visit, the mean (±SD) VA and CSMT were 1.4± 0.7 (p-value=0.45) and 396± 184 μm (p-value=0.11), respectively. Overall, patients showed a partial response without a significant worsening of the macular edema and VA. No complications were reported following repetitive intravitreal injections.Conclusion: Macular edema in silicone oil-filled eyes may be safely and effectively treated with intravitreal injections to halt its deterioration and preserve vision, especially when SiO removal is not anticipated in the foreseeable future.Keywords: intravitreal injections, silicone oil, retinal detachment, Retina, optical coherence tomography, OCT, macular edema, cystoid macular edema, CME

Abstract Background We aimed to compare results of clinical presentation of rhegmatogenous retinal detachment (RRD), and the surgical approach during partial or complete lock-down periods (LP), and non-COVID periods in a tertiary ophthalmology clinic. Methods The medical data of the patients who were diagnosed with RRD in a tertiary hospital. The demographic data of patients, the duration from the beginning of the visual symptoms to hospital admission, the status of lens, the anatomical quadrant of retinal break, best-corrected visual acuity (BCVA) at presentation, the type of intraocular tamponade, and final BCVA were recorded. The exclusion criteria were RD other than rhegmatogenous (tractional or exudative), and incomplete follow-up until 2nd-year. Results The study included 20 eyes of 20 RRD cases in partial LP, 20 eyes of 20 RRD cases in complete LP, and 23 eyes of 23 RRD cases in non-COVID period. The ratio of perfluoropropane (C3F8) gas to silicone oil which was applied as intraocular tamponade at the end of the surgery for RRD was 15/8 in non-COVID period, 11/9 in partial LP, and 11/9 in complete LP (p = 0.730). In final visit at postoperative 2nd-year, the BCVA was logMAR 0.613 ± 0.425 in non-COVID period, logMAR 0.668 ± 0.348 in partial LP, and logMAR 0.730 ± 0.368 in complete LP (p = 0.612). In both inferior and superior quadrant RD, there was significant difference between baseline and final BCVA after surgery. (Baseline and final BCVA in inferior RD: logMAR 1.71 ± 0.40, and logMAR 0.950 ± 0.30 (p = 0.011) and, in superior RD: logMAR 1.35 ± 0.59, and logMAR 0.505 ± 0.321 (p = 0.0001), respectively.) Conclusions As a result, it seems that both partial and complete LP did not modify the typology of RRD surgeries. Trial registration Retrospectively registered. The study followed the tenets of the Declaration of Helsinki, and it was approved by the local ethical committee (2023-088).

Purpose: to conduct a comparative analysis of the clinical efficacy of a fixed combination of antihypertensive drugs: brinzolamide 1 % = timolol 0.5 % and dorzolamide 2 % = timolol 0.5 % for the prevention of intraocular hypertension in patients with silicone oil tamponade of the vitreal cavity.Patients and methods. The study was conducted in the Orenburg branch of S. Fyodorov Eye Microsurgery Federal State Institution during 2022. A retrospective analysis of case histories of 60 patients with retinal detachment and severe proliferative syndrome was carried out. All patients underwent subtotal vitrectomy. To prevent intraocular hypertension after tamponade of the vitreal cavity with silicone oil, patients were prescribed antihypertensive drugs: group 1 (n = 30) — a combination of brinzolamide 1 % = timolol 0.5 %; group 2 (n = 30) — dorzolamide 2 % = timolol 0.5 %. The therapeutic result was evaluated after 2 weeks, 1, 2 and 3 months. The observation included an ophthalmological examination, as well as a questionnaire to assess drug tolerance.Results. IOP after silicone oil tamponade and before the application of drugs had no statistically significant differences between the studied groups and amounted to 27.15 ± 3.56 mm Hg — in group 1 and 28.53 ± 5.99 mm Hg — in group 2. Both studied combinations provided a decrease in IOP, however, a more pronounced effect after 2 weeks of therapy with subsequent maintenance of a normal IOP level for 3 months was recorded in group 2 when using the dorzolamide / timolol combination, despite the appearance of minor discomfort during instillation. A decrease in IOP from baseline was found to be 43.5 % (p ≤ 0.01) with the combination dorzolamide/timolol and 33.3 % (p ≤ 0.01) for brinzolamide/timolol.Conclusion. The results of the study showed that both fixed combinations of drugs provide a decrease in IOP in patients after silicone tamponade, but the dorzolamide/timolol combination had a more pronounced therapeutic effect.

Purpose: To estimate the vitreous cavity replacement volume after pars plana vitrectomy and analyze its correlation with axial length and refractive error. Methods: Observational cross-sectional study on 103 eyes undergoing vitrectomy. Fluid-air exchange was performed using a soft-tip cannula connected to a PVC tubing, the distal end of which opened into a 10-cc syringe without the plunger. The collected fluid was measured (and correction factors applied) to estimate the vitreous cavity volume. Results: The mean axial length of 103 eyes was 23.43 ± 1.54 mm. The mean vitreous cavity volume was 4.46 ± 0.83 mL (2.8–8.1 mL). There was a strong positive correlation between axial length and vitreous volume, which was stronger for pseudophakic and aphakic groups than for phakic groups. Conclusion: Accurate assessment of vitreous cavity volume can enable precise quantification of tamponade, intravitreal drugs, and intravitreal chemotherapeutic agents. This will allow better surgical outcomes, decreased toxicity, and increased cost-effectiveness due to lesser wastage. Objective: To estimate the vitreous cavity replacement volume after pars plana vitrectomy and analyze its correlation with axial length and refractive error.

Over half a century has passed since the inception of vitrectomy, and the indications for its utilization in ophthalmology encompass the majority of vitreoretinal disorders. Technological advancements and equipment innovation have drastically reduced the surgical risk of vitrectomy, but some complications remain unavoidable. Occasionally, unexpected or unexplained visual impairments can manifest. Vitrectomy is associated with a high incidence of optic neuropathy, which can manifest weeks to months following the procedure and result in permanent visual impairment. An intraoperative optic nerve injury and a postoperative secondary injury comprise the causes. Intraocular pressure, dye toxicity, or mechanical damage can cause intraoperative optic nerve injury. Secondary injuries that occur after surgery include an increase in intraocular pressure, toxicity to silicone oil, oxidative stress, and other alterations in the microenvironment. This review will discuss the common causes, clinical manifestations, and related management of optic neuropathy connected to vitrectomy in order to attract the interest of ophthalmologists.

Abstract Background This study aimed to precisely predict the size and silicone oil injection of a foldable capsular vitreous body (FCVB) via computerized three-dimensional (3D) ocular reconstruction in the treatment of severe retinal detachment in China. Methods The 3D software Unigraphics NX was applied to determine the volume of the inner cavity with 16–30 mm axial length, assigning the anterior and posterior chambers, the FCVB sizes, and the silicone oil injection volume, and modeling the data between the axial length and the FCVB size. In clinical practice, IOL Master was applied to accurately measure the axial length of the contralateral healthy eye to anchor the anterior-posterior and horizontal diameters of the operated eye in horizontal position CT, and compared with the model to recommend the FCVB size and silicone oil amount, and the clinical effect was validated in cases across five hospitals in China. Results For the axial length of 16–30 mm, the volume of the inner cavity is 1.2 ml-8.4 ml. FCVB size and silicone oil volume were recommended based on this volume of the inner cavity. Of 253 cases, we noted 11 cases implanted with AV-10P and 1.05 ± 0.21 ml of silicone oil, 41 with AV-12P and 1.58 ± 0.18 ml of silicone oil, 163 with AV-13.5P and 2.48 ± 0.29 ml of silicone oil, 31 with AV-15P and 3.57 ± 0.39 ml of silicone oil, and 7 with AV-17P and 5.71 ± 0.81 ml of silicone oil. There was no significant difference in postoperative visual acuity scores compared with preoperative (P = 0.097), postoperative IOP(10.29 ± 0.57mmHg)was slightly higher than preoperative IOP (9.76 ± 0.48 mmHg), but there was still no statistically significant difference between the two comparisons (P = 0.405). Conclusion Three-dimensional reconstruction prediction is a good solution for eyeballs with obvious individualized changes in severe retinal detachment, and this method helps doctors standardize FCVB size selection and the silicone oil amount for patients.

Abstract Background Cystoid macular edema (CME) can develop following silicone oil placement in complex vitreoretinal surgeries, contributing to poor visual outcomes. In this study, we investigated the clinical and surgical characteristics associated with the development of CME following the use of silicone oil (SO) in pars plana vitrectomy (PPV) surgeries. Methods We conducted a retrospective chart review of patients who underwent implantation of SO during PPV from 2010 to 2020 by a single surgeon. Patient demographics, type of oil, duration of oil tamponade, retinectomy size, diabetic status, lens status, prior panretinal photocoagulation, visual acuity, and incidence of CME were reviewed. Results This study included 43 eyes from 40 patients who underwent SO tamponade for retinal detachment (RD) surgery. The mean duration of SO tamponade was 15.7 ± 12.7 months (range: 1–58 months). The most common indication for surgery was diabetic tractional RD (32.7%), followed by traumatic RD (16.3%) and rhegmatogenous RD with proliferative vitreoretinopathy (11.6%). Of the 43 eyes, 18 (41.9%) developed CME for the first time after PPV with SO placement, with 8 (44%) resolving within a year of oil removal. The mean duration for the development of CME was 9 months. A logistic regression model showed that a scleral buckle procedure and poor initial vision were statistically significant factors for predicting the development of CME (ORs: 11.65 and 16.06, respectively). Overall, 91% of the patients had stable or improved vision after surgery. Conclusions The use of a scleral buckle procedure and poor initial vision are significant factors for predicting CME following silicone oil tamponade in PPV surgeries, with 41.9% of patients developing CME with an average duration of 9 months. Recognizing such factors can lead to early monitoring and prompt management of CME. Meeting presentation Partial analyses were presented at the ASRS 2020 conference. Clinical trial number Not applicable.

Abstract Purpose To report the rate of retinal redetachment after silicone oil removal following rhegmatogenous retinal detachment surgery and to determine potential risk factors. Methods Retrospective observational case series of 161 eyes who underwent rhegmatogenous retinal detachment surgery and subsequent silicone oil removal. Pre- and intraoperative risk factors were evaluated using univariate and multivariate logistic regression. We also evaluated the effect of tamponade duration on anatomical outcomes. Results The median tamponade duration was 5.9 [4.3;7.6] months. Seventeen (10.6%) eyes underwent silicone oil removal within 3 months of surgery, with a median delay of 2.3 [2.0;2.8] months. The rate of retinal detachment after silicone oil removal was 14.9%. A history of previous unsuccessful surgery was the only significant risk factor for retinal redetachment after silicone oil removal (OR 4.8, 95%CI [1.5;19.0], p = 0.02). The use of 360° laser retinopexy and concomitant air or gas tamponade during silicone oil removal were not found to affect the redetachment rate. Eyes with silicone oil tamponade ≤ 3 months showed an increased, albeit not significant, risk of developing recurrent rhegmatogenous retinal detachment after silicone oil removal (35.3% versus 12.5%, p = 0.06). Conclusion A retinal redetachment occurred in 14.9% of eyes undergoing silicone oil removal following rhegmatogenous retinal detachment surgery. Previous failed surgery was associated with a 4.8-fold increased risk of developing recurrent rhegmatogenous retinal detachment after silicone oil removal. Eyes with silicone oil tamponade ≤ 3 months tended to have a higher redetachment rate. Trial registration number ID NCT05647928 (12th April 2022)

BACKGROUND: Retinal detachment is a leading cause of impaired vision and blindness, affecting 2–9% of individuals. Research has shown that local immune-inflammatory processes contribute significantly to the development of this condition. Polymethylsiloxane has long been used as a tamponade substance in the treatment of retinal detachment. It is currently utilized in various forms of retinal detachment as well as in the management of complications such as retinal edge folding and vitreous opacity. However, the use of silicone oil in the vitreous cavity can lead to the development of secondary ocular hypertension and glaucoma, with prevalence rates ranging from 2.2% to 64.2% according to studies. AIM: Conduct a comparative analysis of biochemical and morphometric indicators and justify the expediency of conducting immune therapy for patients with secondary silicone-induced glaucoma. METHODS: A prospective study included 22 patients (22 eyes) in the main group and 22 patients in the comparison group (22 eyes). The average age of the patients was 55±5.3 years (46–68 years), with 28 females and 16 males. Patients in the main group received anti-cytokine therapy (aminopropyldithioethylene-diamine sodium and anakinra). The primary endpoint of the study was the assessment of retinal nerve fiber layer thickness and perimetric indices. RESULTS: The results revealed an inverse relationship between cytokine levels and retinal nerve fiber layer thickness in patients who underwent vitrectomy with silicone tamponade. Additionally, a direct relationship was observed between the diameter of emulsified silicone in the anterior chamber and cytokine levels. The impact of mechanical fragmentation of polymethylsiloxane during nystagmus and direct toxic effects on optic nerve fibers requires further investigation. The study also highlighted the need for more accurate methods of selecting anterior chamber fluid for evaluating the effectiveness of immune therapy. Determining the appropriate dosage, duration, and administration method of anti-cytokine drugs also requires further research. Evaluation of ophthalmotonometric indicators, retinal nerve fiber layer thickness, and mean deviation revealed significantly better outcomes in patients receiving anti-cytokine therapy compared to the control group. CONCLUSION: The findings of this study support the use of anti-cytokine therapy to normalize biochemical parameters in the anterior chamber and reduce clinical manifestations of secondary silicone-induced glaucoma.

Vitrectomy followed by endotamponade of the vitreal cavity with silicone oil (SO) is one of the main techniques of treating severe forms of regmatogenic retinal detachment (RRD). Endotamponade with SO, having numerous advantages and a huge potential, carries the risk of a number of complications arising at various times of application. The literature review analyzes the published data on the effect of tamponade SO on the retina and the function of central vision in RRD surgery: visual acuity, indicators of light and color sensitivity, data of electrophysiological test results. Possible causes of deteriorated central vision functions directly or indirectly related to tamponade with SO are discussed: changes in the thickness and structure of the retina or its individual layers as shown by optical coherence tomography (OCT) data, microcirculation disorders according to OCT angiography, fluorescein angiography, Doppler laser scanning, as well as pathohistological findings related to SO migration into the fundus of eye tissues.

Kirika Kanai, Yuro Igawa, Midori Tachibana, Yuji Yoshikawa, Takeshi Katsumoto, Masayuki Shibuya, Tatsukata Kawagoe, Jun Makita, Kei Shinoda Departments of Ophthalmology, Saitama Medical University, Faculty of Medicine, Saitama, 350-0495, JapanCorrespondence: Kei Shinoda, Departments of Ophthalmology, Saitama Medical University, Faculty of Medicine, 38 Moro-Hongo Moroyama-machi, Iruma-gun, Saitama, 350-0495, Japan, Tel +81-49-276-1250, Fax +81-49-295-8002, Email shinok@saitama-med.ac.jpPurpose: To determine the physiological status of the retina by electroretinography (ERG) using skin electrodes and the RETevalTM system in eyes that had undergone pars plana vitrectomy (PPV) with silicone oil (SO) tamponade. The vitrectomy was performed for a retinal detachment and proliferative diabetic retinopathy (PDR).Design: Retrospective case series.Methods: ERGs were recorded with the RETevalTM system (LKC Technologies Inc. Gaithersburg, MD; Welch Allyn, Inc. Skaneateles Falls, NY) from eight eyes with PDR before and after the SO removal. The amplitudes and implicit times of the a- and b-waves of the ERGs before the SO removal were compared to that after the SO removal.Results: ERGs were recordable in four eyes before and after the SO removal and the a- and b-amplitudes improved in three eyes and worsened in one eye after the SO removal. In the remaining four eyes, ERGs were non-recordable both before and after the SO removal.Conclusion: These results indicate that ERGs picked up by skin electrodes can be used to assess the physiology of the retina in eyes with a SO tamponade. The flat ERGs in the SO-filled eye indicated the presence of diffuse retinal damage which was confirmed by the flat ERGs after the SO removal.Plain Language Summary: There has been an increasing number of reports on evaluating the retinal function using electroretinography (ERG) with skin electrodes. The main advantage of this system is the ability to record ERGs with a skin electrode that does not touch the cornea and ocular surface. This reduces the risk of infection especially in the postoperative period and in clinical situations where infection is suspected. In addition, there have been only a few reports evaluating the function of the retina by ERG in SO-filled eyes.We recorded ERGs with the RETeval (LKC Technologies Inc. Gaithersburg, MD; Welch Allyn Inc. Skaneateles Falls, NY) device, a relatively new ERG recording system that uses skin electrodes and is less invasive. We recorded ERGs from eight SO-filled eyes with proliferative diabetic retinopathy (PDR). In 4 SO filled eyes, the amplitudes increased in three eyes after the SO removal. In the other four eyes, ERGs were non-recordable before and after the SO removal. These results suggest that the RETeval system that uses skin electrodes can be used to assess the retinal function in PDR eyes with a SO tamponade. We suggest that the absence of ERGs in the SO filled eyes was not due to the electrical non-conductive effects of SO but may indicate the presence of diffuse retinal damage which was confirmed after the SO removal.Keywords: electroretinogram, pars plana vitrectomy, proliferative diabetic retinopathy, silicone oil, skin electrode

AbstractPurposeMethodsResultsConclusionThis study aimed to assess and compare the retinal toxicity associated with silicone oil (SO) and perfluoropropane (C3F8) tamponade following vitreoretinal surgery for fresh rhegmatogenous retinal detachment (RRD), utilizing the office-based Diopsys® NOVA™ system for evaluation.Patients who underwent vitreoretinal surgery for fresh RRD and had SO (group 1) or C3F8 (group 2) tamponade were included in a prospective analysis. Flicker full field electroretinography (ffERG) and pattern electroretinography (PERG) tests were performed at 6 months postoperatively.Postoperative best corrected visual acuity (logMAR) was significantly different in group 1 and group 2 patients, 0.48 ± 0.3 and 0.30 ± 0.2, respectively. No significant disparities were found in demographic variables. Flicker ffERG and PERG recordings revealed notable alterations in retinal function parameters in the group 1 compared to the group 2.Our findings suggest a correlation between SO tamponade and retinal dysfunction, evidenced by office-based ERG measurements. The Diopsys® NOVA™ protocol offers clinical ease in assessing retinal function. Further controlled studies are essential to validate these findings and guide clinical practice effectively. [ABSTRACT FROM AUTHOR]

Purpose: To report the rate of retinal redetachment after silicone oil removal following rhegmatogenous retinal detachment surgery and to determine potential risk factors. Methods: Retrospective observational case series of 161 eyes who underwent rhegmatogenous retinal detachment surgery and subsequent silicone oil removal. Pre- and intraoperative risk factors were evaluated using univariate and multivariate logistic regression. We also evaluated the effect of tamponade duration on anatomical outcomes. Results: The median tamponade duration was 5.9 [4.3;7.6] months. Seventeen (10.6%) eyes underwent silicone oil removal within 3 months of surgery, with a median delay of 2.3 [2.0;2.8] months. The rate of retinal detachment after silicone oil removal was 14.9%. A history of previous unsuccessful surgery was the only significant risk factor for retinal redetachment after silicone oil removal (OR 4.8, 95%CI [1.5;19.0], p = 0.02). The use of 360° laser retinopexy and concomitant air or gas tamponade during silicone oil removal were not found to affect the redetachment rate. Eyes with silicone oil tamponade ≤ 3 months showed an increased, albeit not significant, risk of developing recurrent rhegmatogenous retinal detachment after silicone oil removal (35.3% versus 12.5%, p = 0.06). Conclusion: A retinal redetachment occurred in 14.9% of eyes undergoing silicone oil removal following rhegmatogenous retinal detachment surgery. Previous failed surgery was associated with a 4.8-fold increased risk of developing recurrent rhegmatogenous retinal detachment after silicone oil removal. Eyes with silicone oil tamponade ≤ 3 months tended to have a higher redetachment rate. Trial registration number: ID NCT05647928 (12th April 2022) [ABSTRACT FROM AUTHOR]

Anti-VEGF agents, e.g., bevacizumab, are used in retinal surgery, while their interaction with silicone oils and novel hydrogels remains unclear. This study examines the in vitro pharmacokinetics of bevacizumab in silicone oil-filled eyes compared to various hydrogel replacements and the porcine vitreous body as well as its impact on the interface tension of silicone oils. An in vitro model filled with light or heavy silicone oil, porcine vitreous bodies, or hydrogels (alginate and polyethylene glycol (PEG)-based) was equilibrated with a balanced salt solution. Monitoring of bevacizumab in the aqueous phase was conducted for up to 24 h, and its effect on interfacial tension was studied. Significant differences in bevacizumab partitioning were observed across endotamponades after 24 h. In silicone oils, bevacizumab was found exclusively in the aqueous phase, while in the other endotamponades, it accumulated in the gel phase (96.1% in porcine vitreous body, 83.5% in alginate, and 27.6% in PEG-based hydrogel). Bevacizumab significantly reduced interfacial tension (40 to 8 mN/m), possibly enhancing silicone oil emulsification. The type of endotamponade heavily influenced the bevacizumab concentration in the aqueous. The vitreous body and replacement hydrogels likely serve as a drug reservoir, highlighting the need for in vivo studies to explore these interactions prior to clinical application. [ABSTRACT FROM AUTHOR]

This paper presents the fabrication and characterization of plane capacitors utilizing magnetodielectric materials composed of magnetizable microfibers dispersed within a silicone oil matrix. The microfibers, with a mean diameter of about 0.94 μ m, comprise hematite (α -Fe2O3), maghemite (γ -Fe2O3), and magnetite (Fe3O4). This study investigates the electrical behavior of these capacitors under the influence of an external magnetic field superimposed on a medium-frequency alternating electric field, across four distinct volume concentrations of microfibers. Electrical capacitance and resistance measurements were conducted every second over a 60-s interval, revealing significant dependencies on both the quantity of magnetizable phase and the applied magnetic flux density. Furthermore, the temporal stability of the capacitors' characteristics is demonstrated. The obtained data are analyzed to determine the electrical conductance and susceptance of the capacitors, elucidating their sensitivity to variations in microfiber concentration and magnetic field strength. To provide theoretical insight into the observed phenomena, a model based on dipolar approximations is proposed. This model effectively explains the underlying physical mechanisms governing the electrical properties of the capacitors. These findings offer valuable insights into the design and optimization of magnetodielectric-based capacitors for diverse applications in microelectronics and sensor technologies. [ABSTRACT FROM AUTHOR]

This paper reviews the latest trends and applications of silicone in ophthalmology, especially related to intraocular lenses (IOLs). Silicone, or siloxane elastomer, as a synthetic polymer, has excellent biocompatibility, high chemical inertness, and hydrophobicity, enabling wide biomedical applications. The physicochemical properties of silicone are reviewed. A review of methods for mechanical and in vivo characterization of IOLs is presented as a prospective research area, since there are only a few available technologies, even though these properties are vital to ensure medical safety and suitability for clinical use, especially if long-term function is considered. IOLs represent permanent implants to replace the natural lens or for correcting vision, with the first commercial foldable lens made of silicone. Biological aspects of posterior capsular opacification have been reviewed, including the effects of the implanted silicone IOL. However, certain issues with silicone IOLs are still challenging and some conditions can prevent its application in all patients. The latest trends in nanotechnology solutions have been reviewed. Surface modifications of silicone IOLs are an efficient approach to further improve biocompatibility or to enable drug-eluting function. Different surface modifications, including coatings, can provide long-term treatments for various medical conditions or medical diagnoses through the incorporation of sensory functions. It is essential that IOL optical characteristics remain unchanged in case of drug incorporation and the application of nanoparticles can enable it. However, clinical trials related to these advanced technologies are still missing, thus preventing their clinical applications at this moment. [ABSTRACT FROM AUTHOR]

Our report describes a series of three patients with irreversible visual loss after use of silicone oil tamponade. They were operated on by vitrectomy with silicone oil injection due to rhegmatogenous retinal detachment. Postoperatively, optical coherence tomography angiography showed an increase of the foveal avascular zone of the deep retinal plexus and a decrease in density of foveal capillaries. These findings may suggest foveal ischemia as a cause of unexplained visual loss. [ABSTRACT FROM AUTHOR]

[Display omitted] 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. [ABSTRACT FROM AUTHOR]

To establish whether Densiron 68, a heavier-than-water endotamponade agent, is an effective alternative to conventional light silicone oil in primary rhegmatogenous retinal detachment (RD) surgery for eyes with inferior breaks in the detached retina and severe proliferative vitreoretinopathy (PVR). Cohort study of routinely collected data from the European Society of Retina Specialists and British and Eire Association of Vitreoretinal Surgeons vitreoretinal database between 2015 and 2022. All consecutive eyes that underwent primary rhegmatogenous RD surgery using Densiron 68 or light silicone oil as an internal tamponade agent. To minimize confounding bias, we undertook 2:1 nearest-neighbor matching on inferior breaks, large inferior rhegmatogenous RDs, PVR, and, for visual analyses, baseline visual acuity (VA) between treatment groups. We fit regression models including prognostically relevant covariates, treatment–covariate interactions, and matching weights. We used g-computation with cluster-robust methods to estimate marginal effects. For nonlinear models, we calculated confidence intervals (CIs) using bias-corrected cluster bootstrapping with 9999 replications. Presence of a fully attached retina and VA at least 2 months after oil removal. Of 1061 eyes enrolled, 426 and 239 were included in our matched samples for anatomic and visual outcome analyses, respectively. The primary success rate was higher in the Densiron 68 group (113 of 142; 80%) compared with the light silicone oil group (180 of 284; 63%), with an adjusted odds ratio of 1.90 (95% CI, 1.63–2.23, P < 0.001). We also observed a significant improvement favoring Densiron 68 of –0.26 logarithm of the minimum angle of resolution (logMAR) in postoperative VA between the 2 groups (95% CI, –0.43 to –0.10, P = 0.002). The anatomic benefit of using Densiron 68 in eyes with inferior retinal breaks and large detachments was more pronounced among eyes with PVR grade C. We found no evidence of visual effect moderation by anatomic outcome or foveal attachment. Densiron achieved higher anatomic success rates and improved visual outcomes compared with conventional light silicone oil in eyes with inferior retinal pathology and severe PVR. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article. [ABSTRACT FROM AUTHOR]

Introduction: Volatile Organic Compounds (VOCs), despite their small share in the atmospheric pollutants, are the main cause of environmental problems and human health risks. In the biological processes, all the pollution is converted into carbon dioxide and biomass. A large number of industries discharge a mixture of pollutants such as n-hexane and methanol into the atmosphere. The different chemical and physical properties of these materials affect the rate of biological degradation and their removal efficiency by a specific microbial population. Among these properties, the solubility of each component may affect the interaction between the compounds during the biodegradation of the n-hexane/methanol mixture. To overcome the limitation of mass transfer and the low solubility of hydrophobic VOCs such as n-hexane in the water phase, it has been reported to be useful to add a non-aqueous phase (NAP) to the culture medium to absorb the hydrophobic compound. According to the previous research, it is clear that the presence of silicone oil as an NAP has a positive effect on the simultaneous removal efficiency of methanol as a hydrophilic and n-hexane as a hydrophobic pollutant. However, its effect on the kinetic of biodegradation of VOCs is not well known. Therefore, this study aims to determine the effect of different volume fractions of silicone oil on the kinetics of simultaneous biodegradation of n-hexane and methanol. Material and Methods: n-hexane (5 g.m-3 ) was selected as a hydrophobic pollutant, methanol (1 g.m-3 ) as a hydrophilic pollutant, and silicone oil as the NAP. The microbial consortium used in this research was a mixed culture that was isolated from the adapted activated sludge from the return sludge flow of Unit No. 6 of the South Tehran Wastewater Treatment Plant. A gas chromatography (GC) device equipped with a capillary column and flame ionization detector (FID) was used to measure the concentrations of n-hexane and methanol. To measure the concentration of carbon dioxide, a thermal conductivity detector (TCD) was used. To measure the biomass concentration a spectrophotometer was used to determine the optical density (OD) of the samples. Results and Discussion: The specific degradation rate (SDR) of methanol decreased from 1.42 mgmethanol.(gbiomass.day)-1 ) to 1.08 mgmethanol.(gbiomass.day)-1 ) by increasing the volume fraction of silicone oil from 1% to 20% v/v. In contrast, when volume fraction of silicone oil reached 10% v/v, the SDR of n-hexane increased from 17.5 (mghexane.(gbiomass.day)-1 ) to 21 (mghexane.(gbiomass.day)-1 ). Further increasing in the volume fraction of silicone oil up to 20% v/v did not have much effect on the SDR of n-hexane. The kinetics of n-hexane biodegradation followed the Michaelis-Menten model. The addition of 1 g.m-3 of methanol to the culture medium had a negative effect on the SDR of n-hexane, and the presence of methanol increased the Ks value to 21 g.m-3 and decreased the maximum SDR of n-hexane from 141.4 to 123.1 (mghexane.(gbiomass.day)-1 ). Conclusions: The presence of silicone oil in the culture medium reduced the negative effect of methanol on the biological degradation of n-hexane. The increase in the amount of silicone oil up to 10% v/v was effective on the biodegradation rate of n-hexane, and its further increase did not have an effect on the SDR of n-hexane. [ABSTRACT FROM AUTHOR]

Abstract Background The main purpose of this paper is to introduce a method that can accurately locate the posterior capsule of the lens to facilitate a relatively complete resection of the anterior vitreous body. Methods A total of 51 patients in the experimental group and control group were enrolled in this study. Phacoemulsification combined with vitrectomy was performed in all cases. After the cataract procedure was completed in the control group, the surgeon performed a conventional anterior vitrectomy with the operative eye. In the experimental group, anterior vitrectomy was performed according to the threadiness corrugation of the posterior capsule of the lens. During the operation, with the help of triamcinolone, two surgeons confirmed the resection of the anterior vitreous cortex; the best corrected visual acuity and intraocular pressure of all patients were recorded at 1 week, 1 month and 3 months after surgery. Results Fifty patients underwent phacoemulsification combined with vitrectomy, except one patient in the experimental group who was lost to follow-up. After surgery, no significant complications were observed in all patients except two patients in the control group with temporary increases in intraocular pressure. There was no significant difference in preoperative visual acuity between the two groups (t = 0.83, P = 0.25). Both groups had varying degrees of improvement in best corrected visual acuity at 1 week, 1 month and 3 months after surgery. Moreover, there was no significant difference in BCVA between the two groups at the three follow-up time points (t=-1.15, -1.65, -1.09, P = 0.53, 0.21, 0.23). After surgery, no significant complications were observed in all patients except two patients in the control group with temporary increases in intraocular pressure. Incomplete resection of the anterior vitreous cortex was observed in 2 patients in each group, but there was no significant difference (χ2 = 7.81, P > 0.05). Conclusion In the process of cataract surgery combined with vitrectomy, thready corrugation appears in the posterior capsule of the lens and is an important sign of its localization. Anterior vitrectomy can be accomplished safely and effectively with the help of thread-like corrugation, and the surgical effect is almost the same as that of traditional surgery. Especially suitable for beginners in vitreous surgery.

Abstract 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).

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.

Copper nanoparticles are widely used in many sectors and research endeavors owing to their unique properties, including a large surface area, catalytic capabilities, and high thermal and electrical conductivity. The selection of the base fluid for copper nanoparticles should be contingent upon the anticipated application requirements since various fluids exhibit distinct characteristics that could potentially impact the mobility of the nanoparticles. The present investigation analyzes heat transfer phenomena occurring across a radially stretched surface. The research explores the effects of different states of Cu nanoparticles when combined with base fluids, such as water and silicone oil, on the heat transfer process. The momentum and energy equations are transformed into nonlinear ordinary differential equations by applying the similarity transformation. The boundary value problem-fourth-order (BVP4C) method numerically solves the governing ordinary differential equation for the modeled problem. In addition, the influence of various factors such as the slip parameter, solid volume fraction, Eckert number, Prandtl number, and unsteadiness parameter are examined. It has been discovered that blade-shaped nanoparticles transfer heat as quickly as possible via silicone oil and water. However, for platelet-shaped nanoparticles, a minimum heat transfer rate has been noted. The maximum skin friction coefficient is observed in platelet-shaped nanoparticles, while blade-shaped nanoparticles have the lowest skin friction coefficient.

Background: The main purpose of this paper is to introduce a method that can accurately locate the posterior capsule of the lens to facilitate a relatively complete resection of the anterior vitreous body. Methods: A total of 51 patients in the experimental group and control group were enrolled in this study. Phacoemulsification combined with vitrectomy was performed in all cases. After the cataract procedure was completed in the control group, the surgeon performed a conventional anterior vitrectomy with the operative eye. In the experimental group, anterior vitrectomy was performed according to the threadiness corrugation of the posterior capsule of the lens. During the operation, with the help of triamcinolone, two surgeons confirmed the resection of the anterior vitreous cortex; the best corrected visual acuity and intraocular pressure of all patients were recorded at 1 week, 1 month and 3 months after surgery. Results: Fifty patients underwent phacoemulsification combined with vitrectomy, except one patient in the experimental group who was lost to follow-up. After surgery, no significant complications were observed in all patients except two patients in the control group with temporary increases in intraocular pressure. There was no significant difference in preoperative visual acuity between the two groups (t = 0.83, P = 0.25). Both groups had varying degrees of improvement in best corrected visual acuity at 1 week, 1 month and 3 months after surgery. Moreover, there was no significant difference in BCVA between the two groups at the three follow-up time points (t=-1.15, -1.65, -1.09, P = 0.53, 0.21, 0.23). After surgery, no significant complications were observed in all patients except two patients in the control group with temporary increases in intraocular pressure. Incomplete resection of the anterior vitreous cortex was observed in 2 patients in each group, but there was no significant difference (χ2 = 7.81, P > 0.05). Conclusion: In the process of cataract surgery combined with vitrectomy, thready corrugation appears in the posterior capsule of the lens and is an important sign of its localization. Anterior vitrectomy can be accomplished safely and effectively with the help of thread-like corrugation, and the surgical effect is almost the same as that of traditional surgery. Especially suitable for beginners in vitreous surgery. [ABSTRACT FROM AUTHOR]

Silicone oil is a commonly used lubricant in pre-filled syringes (PFSs) and can migrate over time into solution in the form of silicone oil particles (SiOPs). The presence of these SiOPs can result in elevated subvisible particle counts in PFS drug products compared to other drug presentations such as vials or cartridges. Their presence in products presents analytical challenges as they complicate quantitation and characterization of other types of subvisible particles in solution. Previous studies have suggested that they can potentially act as adjuvant resulting in potential safety risks for patients. In this paper we present several analytical case studies describing the impact of the presence of SiOPs in biotherapeutics on the analysis of the drug as well as clinical case studies examining the effect of SiOPs on patient safety. The analytical case studies demonstrate that orthogonal techniques, especially flow imaging, can help differentiate SiOPs from other types of particulate matter. The clinical case studies showed no difference in the observed patient safety profile across multiple drugs, patient populations, and routes of administration, indicating that the presence of SiOPs does not impact patient safety. [ABSTRACT FROM AUTHOR]

According to the published articles, the capacity and output of silicone methyl monomer, the import and export of primary polysiloxane, the revenue of listed enterprises in silicone, the new projects, the formulation of policies in silicone in 2023 were summarized, and the R&D in silicone (including R&D investment of enterprises, self-developed projects of enterprises and R&D priorities in silicones) was also introduced. [ABSTRACT FROM AUTHOR]

Paper substrates possessing features ranging from hydrophobic to oxygen-barrier functional properties are gaining great attention recently due to the global ban on single-use plastics as well as the compulsion to avoid nonbiodegradable polymer packing. In this work, hydrophobic silica carriers are processed first through a direct physical impregnation of silicone oil in various amounts into the 20-nm sized silica nanoparticles and subsequently analyzed for the progressive changes in the surface hydrophobicity by water contact angle measurements. The hydrophobic nano-silica was also systematically analyzed by XRD, TGA, FTIR, SEM, and TEM and the results are presented. It was found that the nano-silica with the bulk BET surface area of 157 m2/g can accommodate 2.5 g of silicone oil per gram of silica, finally resulting in hydrophobic silica with a maximum contact angle of 139°. Later, this hydrophobic nano-silica was dispersed in a polymethylmethacrylate (PMMA) matrix and a coating formulation was prepared to develop water-repellent self-cleaning functional coatings on eco-friendly paper substrates. While applied as topcoats on paper substrates, the hydrophobic silica-PMMA gets embedded into the porous fibrous cellulose network and converts it into an impressive water-repellent packaging material with a contact angle of about 142°. This facile inorganic–organic hybrid topcoat strategy was successfully applied on the fibrous cellulose sludge waste produced by the paper mills to produce lightweight, water/moisture resistance packing material for circular economy. [ABSTRACT FROM AUTHOR]

In order to study the sedimentation stability of silicone oil-based magnetorheological fluids with fumed silica as additive, magnetorheological fluids with different mass fractions of fumed silica, particle sizes of carbonyl iron powder and viscosities of silicone oil were prepared. The sedimentation rate of magnetorheological fluids was calculated by observation method, and the zero-field viscosity of magnetorheological fluids was measured by viscometer. The results show that the sedimentation rate and viscosity of magnetorheological fluids increase gradually with the increase of the mass fraction of fumed silica. The mass fraction of fumed silica should not be constant for magnetorheological fluids, but should be determined according to the content of silicone oil in magnetorheological fluids. With the increase of average diameter of carbonyl iron powder, the sedimentation stability of magnetorheological fluids becomes worse. With the increase of viscosity of silicone oil, the sedimentation stability of magnetorheological fluids does not increase significantly. However, the high viscosity of silicone oil will result in wall hanging phenomenon, and increase the start-up difficulty of magnetorheological device. With 2.5 wt% of fumed silica for silicone oil, the magnetorheological fluids has good sedimentation stability and suitable zero-field viscosity. [ABSTRACT FROM AUTHOR]

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). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose: To propose a minimum specification dataset to characterize liquid ocular endotamponades (OEs), namely silicone oil (SO), heavy SO (HSO), perfluorodecalin (PFD), and perfluoro-octane (PFO), in terms of physicochemical properties, purity and available evidence of safety, in line with ISO16672:2020. Methods: An evidence-based consensus using the expert panel technique was conducted. Two facilitators led a committee of 11 European experts. Facilitators prepared a dataset for each compound including the list of specifications relevant for the safety, identified by the group members on the basis of expertise and a comprehensive literature review. Each item was ranked by each member using a 9-point scale from 1 "absolutely to not include" to 9 "absolutely to include" in two rounds followed by discussion. Only items reaching consensus (score ≥ 7 from ≥ 75% of members) were included in the final datasets. Results: For all OEs, consensus was reached to include manufacturer, density, refractive index, chemical composition, dynamic viscosity, interfacial and surface tension, endotoxins, in vitro cytotoxicity assessment, and any evidence from ex vivo and/or in vivo tests for safety assessment. Additional specifications were added for SO (molecular weight distribution, content of oligosiloxanes with MW ≤ 1000 g/mol, spectral transmittance) and PFD/PFO (% of pure PFD/PFO in the final product, vapor pressure, chemical analyses performed for safety assessment). Conclusion: The proposed evidence-based minimum specification datasets for SO, HSO, PFD, and PFO have the potential to provide surgeons and health service purchasers with an easily available overview of the most relevant information for the safety assessment of OEs. [ABSTRACT FROM AUTHOR]

Purpose: Silicone oil droplets in biopharmaceutical products can originate from sources such as siliconized surfaces of primary packaging materials, potentially triggering the formation of protein–silicone oil particles. To better understand this phenomenon, there is a need for particle detection devices that cannot only distinguish between protein particles and silicone oil droplets but also determine particle sizes ranging from nanometers to micrometers. Method: In this study, we conducted a systematic assessment of imaging flow cytometry (IFC) using the FlowSight® instrument. Our first step was to investigate specific instrument settings using protein particle samples spiked with silicone oil for particle classification. Based on these findings, we established suitable, harmonized working templates. Next, we evaluated the instrument’s accuracy and precision for particle sizes within the range of 0.5 to 100 µm and their respective concentrations. Finally, we investigated any constraints in particle concentration within this size range. Results: This study demonstrates that IFC can effectively distinguish protein particles from silicone oil droplets when the latter is labeled with a specific fluorescent dye. Our findings suggest that fluorescently labeled particles ≥ 0.5 µm can be reliably detected. Through our research, we determined the particle concentration limits for each particle size in the range of 0.5 to 10 µm, with a precision deviation of less than 15%. However, our study also revealed that IFC exhibited insufficient accuracy for the tested particle concentrations within this size range. Additionally, we showed that the measurements were significantly influenced by the instrument settings. Conclusion: Although we addressed numerous new aspects to enhance the experimental procedure of IFC measurements, we conclude that IFC is not an ideal technique for quantifying sub-visible particles. Instead, it should be employed to provide supportive characterization data in conjunction with commonly used sub-visible particle detection methods. If distinguishing between protein particles and silicone oil droplets is essential, IFC is an option, as long as the fluorescent dye is carefully selected. [ABSTRACT FROM AUTHOR]

In petroleum production, silicone oil (polydimethylsiloxane or PDMS) remains the most efficient product for combating foam, despite its negative effects on petroleum contamination and catalytic refining processes. This study aimed to evaluate the defoaming action of silicone oils with varying molar masses (ranging from 3 to 110 kg·mol−1) as defoamers in crude oils with different densities (20, 26, and 30°API). The results were correlated with the dilatational rheology obtained through pendant drop tensiometry of the oil samples. The silicone samples were characterized using gel permeation chromatography and thermogravimetric analysis, while the petroleum samples underwent SARA (saturated, aromatics, resins, asphaltenes) composition analysis, density measurement, and assessment of water content. The PDMS range of 8 to 30 kg·mol−1 exhibited enhanced antifoaming efficiency for the tested oils. A plateau in efficiency was observed when antifoamers were dosed above 15 ppm. Additionally, a reverse relationship between the initial formation of foam and the elastic modulus (G') of the oil in the presence of the antifoamer was observed, suggesting that the more effective antifoamer actually increased the elasticity of the film. [ABSTRACT FROM AUTHOR]

Lexin Ge,&ast; Na Su,&ast; Wen Fan, Songtao Yuan Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Songtao Yuan, Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, No. 300 Guangzhou Road, Nanjing, 210029, People’s Republic of China, Email songtaoyuan@njmu.edu.cnAbstract: 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.Keywords: intraocular pressure, silicone oil, ocular hypertension, pars plana vitrectomy, secondary glaucoma

Abstract Background To evaluate retinal structural and functional changes after silicone oil (SO) removal in eyes with macula-off rhegmatogenous retinal detachment (RRD). Methods Best-corrected visual acuity (BCVA) testing, microperimetry, and optical coherence tomography angiography were performed in 48 eyes with macula-off RRD before and 3 months after SO removal. The values of healthy contralateral eyes were used as control data. Correlations between retinal vessel density (VD), retinal nerve fiber layer thickness (RNFLT), the interval between retinal detachment and surgery, the duration of SO tamponade, the follow-up time after SO removal, and visual function were analyzed. Results Significant increases in 2˚ fixation rate (FR), 4˚ FR, 2˚ mean retinal sensitivity (MRS), 6˚ MRS, parafoveal superficial capillary plexus VD and RNFLT were observed after SO removal (all P 0.05). Conclusion Retinal structure and function improved to different degrees after SO removal. Fixation stability and retinal sensitivity increased more than BCVA postoperatively. Retinal sensitivity, which was affected by the interval between retinal detachment and surgery and the duration of SO tamponade, gradually recovered after SO removal.

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.