Intraocular Silicone Oil Research Articles

Silicone on the Move: Migratory Siliconoma After Retinal Surgery Report of a Case and Review of the Literature.

Silicone granulomas, or "siliconomas," are the common foreign-body inflammatory responses to injected silicone material. In rare cases, siliconomas develop remotely from the original site of injection, secondary to silicone migration. If a history of silicone injection is not noted, such lesions risk misdiagnosis (possibly as infection or malignancy). Intraocular silicone oil is commonly used in retinal detachment surgery, with occasional reports of granulomatous responses after its application in this context. Here, we report a 66-year-old man who developed a periocular silicone granuloma years after scleral buckle surgery for a detached retina and summarize the literature of similar reports of migratory siliconoma.

Contamination Profile of Different Formulations of Silicone Oil Tamponade Before and After Intraocular Permanence for Rhegmatogenous Retinal Detachment.

The purpose of this study was to search for contaminants in silicone oil tamponades removed from eyes treated for retinal detachment, and to correlate chemical results with some clinical/functional parameters of the considered eyes. We examined a sequential cohort of eyes grouped according to the tamponade received: (1) Siluron2000 (S2), (2) RS-OIL ECS5000 (S5), and (3) Densiron Xtra (DX). Samples were collected at the beginning of the scheduled removal and analyzed by untargeted headspace gas-chromatography mass spectrometry (HS-GC-MS). Visual acuity and optic coherence tomography assessments were obtained before and after the tamponade removal. Forty-one samples were analyzed: 22 belonging to the DX group, 13 to the S2 group, and 6 to the S5 group. For each group, a mixture of uninjected commercial preparation was analyzed as the reference. Different siloxanes and fluorinated compounds including perfluorodecalin (PFCL) were the most prevalent chemicals, found in 55% to 100% of the intraocular samples of the 3 groups. Some siloxanes were present also in the control matrices, whereas PFCL was only in the extracted tamponades. In the DX group, the concentration of hexamethylcyclotrisiloxane showed an inverse correlation trend with the duration of its permanence inside the eye (P = 0.054). Different alkanes, propanol, and acetaldehyde were identified only in the control matrices. Several contaminants including siloxanes were identified in the intraocular samples and in the control matrices. A time-related ocular uptake of some of these is conceivable. PFCL was also highly present but only in intraocular samples. After intraocular permanence silicone oils (SOs) have various unlabeled contaminants with some relevant differences with the commercial formulation chemical profile.

Clinical Outcomes of Scleral Buckling combined with Vitrectomy Pars Plana for Rhegmatogenous Retinal Detachment

Introduction & ObjectivesThe various types of primary interventions for rhegmatogenous retinal detachment (RRD) includepars plana vitrectomy (PPV), scleral buckling (SB), and combination of both. Intraocular tamponadewith silicone oil (SO) or expanding gas. This research was conducted to evaluate the clinicaloutcomes of SB combined with PPV as a treatment for RRD.
 MethodsThis research was prospective descriptive study with total sampling for RRD treated by SB combinedwith PPV from August 2022 to January 2023 in RSUP. Prof. Dr. R.D. Kandou. We observed the BCVA,IOP before and after the surgeries. Clinical findings, intraocular tamponade and complications afterthe surgeries were observed.
 ResultsMost of the patients was male with average age of 28 ± 40 years. RRD was observed in 6 eyes andlaterality on right eye. BCVA was 2.5 ± 2 logMAR before the surgery and 2.3 ± 1 logMAR 1 monthafter the surgery. Preoperative IOP was 7 ± 11 mmHg and 13.6 ± 10 mmHg 1 month after thesurgery. Macular detachment, 1 Quadrant Detachment, 1 Number of retina break mostly on superotemporalquadrant were found the most. Proliferative vitreoretinopathy was found in 1 eye.Intraoperative triamcinolone used in 4 eyes and perfluorocarbon in 1 eyes. Subconjunctival bleedingwas found the most, followed by corneal edema and subretinal hemorrhage as postoperativecomplications respectively.
 ConclusionThere were several clinical condition seen such as BCVA after the surgery that didn’t improve asexpected, High IOP found in several eyes and subconjunctival bleeding was the complication foundthe most in these eyes.

Remodelling of the lamina cribrosa thickness in proliferative diabetic retinopathy as a pathogenetic factor of retrolaminar migration of silicone oil after vitrectomy

Aims/Purpose: to analyse the relationship of lamina cribrosa (LC) thickness in patients with proliferative diabetic retinopathy (PDR) after vitrectomy with SiO tamponade with retrolaminar migration of intraocular silicone oil (SiO).Methods: This retrospective study included 35 patients with PDR after vitrectomy with SiO tamponade who underwent unenhanced head computed tomography for various clinical indications. All images were visually evaluated for subretinal and retrolaminar migration of SiO involving the anterior visual pathway (optic nerve, optic chiasm, and optic tract) and the ventricular system. LC thickness was measured with spectral domain optical coherent tomography (SD OCT) using LC_Thickness_programm.m and main_low_noise_filters_programm.m, based on the adaptive compensation algorithm for eliminating a high‐level noise in the deep layers of optic nerve and improving the visualization of the LC posterior border, as well as for processing B‐scan with a set of 3 digital filters: Butterworth Low‐pass Filter inverion image, Wavelet Low‐pass Filter Analysis Daubechies original and inversion image.Results: In our patients with PDR the average LC thickness was 697 ± 35 μm (589 to 768 μm), that was 1.9 times higher than in healthy people (p < 0.001). We detected subretinal and retrolaminar silicone oil migration in 10 of the 35 patients (28.57%), noting silicone oil at the optic nerve head (n = 2), retrolaminar optic nerve (n = 4), optic chiasm (n = 2), optic tract (n = 1) and in the lateral ventricles (n = 3). 3 patients had migration to 2 locations each (1 – in retrolaminar optic nerve and optic chiasm, 2 – in retrolaminar optic nerve and lateral ventricle). We compared the LC thickness of patients without and with subretinal and retrolaminar SiO migration. It was established that LC thickness of patients with subretinal and retrolaminar SiO migration was significantly less (589 to 658 μm) than in patients without SiO migration (673 to 768 μm). It should be noted that the number of cases positive for migration was small, limiting the statistical power and accuracy of the prevalence.Conclusions: A direct correlation between scleral LC thickness and retrolaminar migration of SiO in patients with PDR after vitrectomy with SiO tamponade was revealed.

Conjunctival, Scleral and Corneal Complications in Vitreoretinal Surgery

Vitreoretinal surgery has been associated with corneal, conjunctival and scleral complications. These complications may cover corneal epithelial and endothelial cells damage (epithelial defects, neurotrophic and band keratopathy, refractive error changes, corneal decompansation etc.), ocular surface disease, early hypotonia, diplopia, strabismus, subconjunctival silicone oil, episcleral pigmentation, infection and inflammation etc. Risk factors may include a history of the previous ocular surgery, aphakia and pseudophakia, prolonged duration of surgery, intraoperative epithelial debridement, intraoperative lensectomy, diabetic patients, use of adjunctive intraocular long-acting expansile gases or silicone oil, use of scleral buckling, sutureless sclerotomy incisions etc. These complications should be known and noticed due to affect visual outcomes and healing of patients. Corneal, conjunctival and scleral complications are summarized in this article.

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

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

Unexplained Vision Loss Associated With Intraocular Silicone Oil Tamponade in Rhegmatogenous Retinal Detachment Repair.

Purpose: To evaluate the visual outcomes with unexplained vision loss during or after silicone oil (SO) tamponade. Methods: This multicenter retrospective case series comprised patients with unexplained vision loss associated with SO tamponade or its removal. Eyes with other clear secondary identifiable causes of vision loss were excluded. Results: Twenty-nine eyes of 28 patients (64% male) were identified. The mean age was 50 ± 13 years (range, 13-78 years). The mean duration of SO tamponade was 148 ± 38 days. Eighteen eyes (62%) developed unexplained vision loss while under SO; 11 (38%) had vision loss after SO removal. The most common optical coherence tomography (OCT) finding was ganglion cell layer (GCL) thinning (55%). Eyes with vision loss after SO removal had a mean logMAR best-corrected visual acuity (BCVA) of 0.6 ± 0.7 (Snellen 20/85) before SO tamponade and 1.2 ± 0.4 (20/340) before SO removal. By the last follow-up after SO removal, the BCVA had improved to 1.1 ± 0.4 (20/235). In eyes with vision loss after SO removal, the BCVA before SO removal was 0.7 ± 0.7 (20/104), which deteriorated to 1.4 ± 0.4 (20/458) 1 month after SO removal. By the last follow-up, the BCVA had improved to 1.0 ± 0.5 (20/219). Conclusions: Unexplained vision loss can occur during SO tamponade or after SO removal. Vision loss was associated with 1000-centistoke and 5000-centistoke oil and occurred in macula-off and macula-on retinal detachments. The duration of tamponade was 3 months or longer in the majority of eyes. Most eyes had GCL thinning on OCT. Gradual visual recovery can occur yet is often incomplete.

Clouding of intraocular silicone oil in the absence of emulsification.

To describe intraocular clouding of silicone oil in the absence of emulsification. Retrospective observational case series of patients who received silicone oil injections and developed silicone oil discoloration without emulsification after pars plana vitrectomy. Clinical examinations and physicochemical analyses were performed to find out the common cause for the opaque oil. Thirteen patients developed silicone oil discoloration after pars plana vitrectomy. It could be traced down that all patients had received silicone oil from one respective production batch. The silicone oil was removed as soon as possible after the changes were detected (range, 8-16 weeks). Gas chromatography flame ionization detector (GC-FIC), size exclusion chromatography (SEC) and high performance liquid chromatography (HPLC) analysis showed the absence of small molecular weight compounds in the opaque lot. Thermogravimetric analysis (TGA) revealed the opaque lot was more temperature stable. During the follow-ups, no obvious retinal toxicity could be observed and best recorded visual acuity improved considerably in twelve patients and was only limited by the underlying retinal pathology. This is the first report on opacification of intraocular silicone oil without emulsification. This discoloration of silicone oil may disturb vision and prevent proper fundus examination, however, seems to be a non-toxic phenomenon without serious long-term consequences.

Retinal Nerve Fiber Layer Changes after Intraocular Silicone Oil Tamponade in Rhegmatogenous Retinal Detachment.

Rhegmatogenous retinal detachment (RRD) is a serious and emergency condition that may cause visual disturbance. Treatment includes pars plana vitrectomy with a tamponade such as intraocular gas or silicone oil (SO). In many countries, silicone oil is still favorable compared to intraocular gases as tamponade for reattachment of retinal detachment surgery. The application provides a higher anatomical success rate, especially in cases of proliferative vitreoretinopathy (PVR) that were previously considered untreatable. Objective assessment of the retinal nerve fiber layer (RNFL) using optical coherence tomography (OCT) in the eye with silicone oil tamponade is a challenge because of the limitations and difficulties in taking images. This study aims to assess the RNFL thickness changes in rhegmatogenous retinal detachment patients using SO tamponade and its subsequent removal conducted on a total of 35 post-operative RRD patients. Central macular and RNFL thickness, as well as best-corrected visual acuity (BCVA), were recorded at the time of tamponade and after the removal of the SO at 1, 4, and 8 weeks, respectively. The results showed that the changes in RNFL thickness significantly decreased in the group of ≤6 months, especially in the superior and temporal quadrants, and BCVA increased after SO removal (p < 0.05). Central macular thickness was significant (p < 0.001) at the end of the visit. Improved visual acuity is associated with decreased RNFL and central macular thickness after SO removal.

Surgery for Infectious Retinitis - When Medical Therapy Is Not Sufficient: The Moacyr E. Alvaro Pan-American Lecture 2023

ABSTRACT Background Viral retinitis composes a group of infectious ocular diseases with poor prognoses. With the advent of antivirals and HAART, the treatment of these diseases has evolved and ocular outcomes have improved. However, even with prompt medical treatment, a significant number of patients will experience complications that require surgical intervention. While there has been an abundance of research examining the medical treatment of CMV retinitis and acute retinal necrosis, the research examining surgical outcomes of complications such as retinitis-associated retinal detachment is comparatively limited. Methods Literature review. Results In this review, we discuss the current literature examining treatment of CMV retinitis and acute retinal necrosis, with a focus on surgical management of complications such as retinal detachment. Conclusions Despite significant improvements in the medical treatment of CMV retinitis and ARN over the last three decades, vision-threatening complications such as retinal detachment are relatively common and require surgical management via PPV, laser photocoagulation, and intraocular gas or silicone oil tamponade.

Intraocular Silicone Oil Removed after 10 Years: A Case Report

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

Successive trabecular meshwork photocoagulation in the treatment and prevention of refractory hypotony.

To evaluate the effect of successive trabecular meshwork photocoagulation (sTMP) on the elevation of intraocular pressure (IOP) to treat or prevent refractory hypotony. The IOP changes of 15 refractory hypotonic eyes (or estimated to be hypotonic after silicon oil removal) in 15 consecutive patients were retrospectively analysed after sTMP. Fourteen eyes had intraocular silicone oil that was to be removed. Different lasers were used to destroy the trabecular meshwork 1-5 times (2.00±1.20 times on average) via the gonioscope or endoscope. Twelve eyes had a large area of exposed retinal pigment epithelium due to a large area of retinecotomy, one eye had a severe cyclitic scar, and two eyes had both a scar and a retinal defect. After sTMP (1 to 125 months of follow-up, 22.87±38.88 months), the average IOP in the 15 eyes was 11.70±3.19mmHg (n=15), significantly higher than the value before sTMP (8.26±1.93mmHg, P<0.05). The IOP of the 15 eyes increased by 3.44±2.61mmHg, Eight eyes with an IOP of less than 10mmHg before sTMP showed an IOP ≥10mmHg after sTMP. Following sTMP, the silicone oil was removed from six eyes, and one of these eyes suffered a retinal detachment. sTMP can significantly increase the IOP with a long-lasting effect and provide an opportunity for the removal of silicone oil despite large-area retinal defects or cyclitic scars in selected eyes.

Metallic intraocular foreign body removal assisted through the extrusion line

AbstractPurpose: To describe an alternative vitreoretinal surgical manoeuvre, to remove metallic intraocular foreign bodies.Methods: Two patients, at different time lines, underwent vitrectomy to remove a metallic intraocular foreign body (IOFB). A 3‐port vitrectomy was performed, a 23‐G constellation vitrectomy equipment was used in both procedures, careful core vitrectomy was first done, vitreous adhesions and vitreous detachment was carefully done, retina was partially detached at the IOFB location, vitreous adhesions were cut and released gently not to increase the retinal detachment. Liquid prefluorocarbon was placed on the macula. As the vitreous adherences were cut, the IOFB was free from all potential tractional forces, the soft silicone tip cannula was held on to its surface, and at maximal vacuum aspiration, the IOFB was brought up to the anterior chamber, switching the light pipe for forceps in the other hand, and removed out of the eye. A complete as possible vitrectomy was performed, intraocular laser around the retinal brakes was performed, an intraocular lens was placed in the ciliary sulcus with the optic within the anterior capsule, and silicone oil was used as tamponade.Results: No signs of intraocular inflammation were recorded postoperatively. Intraocular silicone oil removal was done at the third post‐operative month in both cases, retina remained attached through follow up, both patients had over 9 months follow‐up visits, visual acuity improved from initial presentation, and also improved after the silicone oil tamponade removal.Conclusions: Active aspiration through the soft silicon tip cannula can be used to reach, and assist removal of metallic intraocular foreign bodies, being this manoeuvre safe, reproducible, possibly time‐saving, and also it could potentially avoid the risk of IOFB mobilization, avoiding further damage to the retina.

Retinal and Corneal Changes Associated with Intraocular Silicone Oil Tamponade.

Silicone oils (SO) are used as long-term intraocular tamponades and have an irreplaceable role in vitreoretinal surgery. They can, however, be associated with multiple and potentially severe complications, involving different ocular tissues, in particular retina and cornea. Recent advances in ophthalmic imaging have allowed the precise characterization of retinal and corneal microstructural changes, at a subclinical level. This detailed analysis of SO-related retinal and corneal changes has improved our understanding of their pathogenesis and offer the potential for optimized monitoring and management of patients with SO-filled eyes. This review aims to provide clinicians and ophthalmic scientists with an updated and comprehensive overview of the corneal and retinal changes associated with SO tamponade.

Visual acuity reduction and silicone oil tamponade

Silicone oil is an established intraocular surgical aid, which enables the treatment of the most complex starting situations but no other alternative has been found; however, the available data indicate that an unclear loss of visual acuity during or after an intraocular silicone oil tamponade possibly occurs more frequently than assumed from the clinical routine. Various pathological mechanisms are under discussion as causes, but the exact causes are actually unclear. In addition to atrophic alterations in the optical coherence tomography (OCT) examination, there are a clear reduction in visual acuity and mostly a central scotoma with otherwise inconspicuous findings. Unclear loss of visual acuity can also occur after removal of the silicone oil. Whether this is caused by the same pathological mechanism is unclear. Furthermore, there are no reproducible risk factors that appear a priori to possibly cause an unclear loss of vision under silicone oil; however, oil removal as soon as possible and a good adjustment of the intraocular pressure are recommended by the authors. Overall, a silicone oil tamponade should be carefully weighed up even when using modern highly purified silicone oils and it should therefore continue to be reserved particularly for unfavorable initial situations or complicated courses with the necessity for a silicone oil tamponade. Against this background, a study for systematic recording and processing of cases of unclear loss of visual acuity after silicone oil tamponade seems to be meaningful.

Prevalence and implications of the presence of intraocular silicone oil droplets in patients treated with intravitreal injections of anti-VEGF

BackgroundTo determine the percentage of patients who have silicone droplets in the vitreous after treatment with different anti-Vascular Endothelial Growth Factor (anti-VEGF) intravitreal injections (IVI) and how symptomatic they are.MethodsOne hundred fifty-two eyes of 140 patients who had at least received an IVI were recruited for this study. Data collection included the number and type of IVI (aflibercept, ranibizumab and bevacizumab) and the follow-up time. A complete ophthalmologic examination was carried out and patients were classified in four groups according to the amount of silicone droplets found in dilated fundoscopy (nonexistent, scarce, moderate and abundant). Measurement of intraocular pressure (IOP) was also carried out. An interview was conducted to report the presence and intensity of the symptomatology.ResultsSilicone oil droplets were reported in 109 eyes (71.7%). A positive correlation was found between the number of IVIs received and the quantity of droplets found, especially when aflibercept was used. Posterior vitreous detachment (PVD) was present in 65.8% of the patients, showing a positive correlation with the number of bubbles. Regarding the symptomatology, 60 eyes (39.5%) had floaters and the disturbance was reported to be 4 out of 10. The group with a moderate amount of silicone droplets had the highest percentage of floaters (60%). No statistical differences in the IOP were found between groups, although the group with abundant droplets had a higher mean IOP.ConclusionA high prevalence of silicone droplets in vitreous of patients who undergo IVI treatment was found. It appears to have little impact on symptomatology and rise of IOP.

Intracranial silicone oil migration with encephalopathy: a rare case report

BackgroundIntraocular silicone oil (SiO) tamponade is a popular modality of treatment of rhegmatogenous retinal detachment. It can, however, rarely lead to an incompletely understood phenomenon known as intracranial migration of SiO. Though usually benign, this entity is often misinterpreted as a tumour or haemorrhage.Case presentationWe present a case report of a patient with acute progressive encephalopathy and intracranial migration of intravitreal silicone. We also put forward the possibility of toxic effects of intracranial SiO on the central nervous system.ConclusionClinicians and radiologists should be aware of the rare complication of intravitreal SiO tamponade. Eliciting the history of intraocular SiO tamponade and identifying the key imaging features on ultrasonography of the orbit, CT of the head, and MRI of the brain will help in avoiding unnecessary interventions or delays in the management of the patients from misdiagnosing it as haemorrhage or tumour.

DIA Comparative Proteomic Analysis of Retro-oil Fluid and Vitreous Fluid From Retinal Detachment Patients.

Objectives: There have been reports of unexplained visual loss following intra-ocular silicone oil (SiO) tamponade in retinal detachment patients, yet the underlying mechanism is unknown. The aim of this study was to investigate the mechanisms behind retinal toxicity following intra-ocular SiO tamponade in retinal detachment patients. Methods and Results: Vitreous fluid samples were acquired from 27 patients (27 eyes). Twelve eyes for data-independent acquisition (DIA) were divided into four groups: pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RD group), SiO removal after successful retinal reattachment (SO group), cataract surgery after successful retinal reattachment with sterilized air tamponade (FA group), and PPV for epiretinal membrane (ERM group). The remaining 15 eyes were used for enzyme-linked immunosorbent assay analysis. DIA was combined with two-dimensional liquid chromatography–tandem mass spectrometry to find expression changes in the proteome of vitreous. Mean number mass spectra, statistically differentially expressed proteins, gene ontology (GO), pathway representations, and protein interactions were analyzed. GO analysis showed that the protein categories of synapse organization, cell adhesion, and regulation of cell migration in the SO group were differentially expressed compared to the control or FA groups (p < 0.05). Through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, lysosome and cell adhesion were found to be significantly enriched in the SO group compared to the FA and control groups (p < 0.05). Cadherin 2, transferrin, and lysosome function may partially contribute to silicone oil-related vision loss. Conclusion: Vision loss-inducing novel molecular signatures and pathways that may be associated with SiO toxicity were identified. Transferrin may be a potential visual outcome biomarker for SiO tamponade.

Ex vivo evaluation of retinal cytotoxicity after the use of multiple medical devices in pars plana vitrectomy in porcine eyes

This study aimed to evaluate viability of retinal cells after the use of multiple intraoperative devices, namely a vitreal dye (triamcinolone acetonide,TA), a ERM/ILM dye (solution of trypan blue 0.15% and brilliant blue 0.025%), and two intraocular tamponades, namely perfluoro-n-octane, (PFO) and silicone oil (SO 1000 cSt), with minimal and maximal removal of their residues, during a simulated pars plana vitrectomy (PPV) in porcine eyes ex-vivo. The in vitro cytotoxicity of each of these compounds was verified on ARPE-19 cells by direct tests according to the ISO 10993-5 (2009). Pars plana vitrectomy was performed on 25 enucleated porcine eyes divided in five groups according to the following conditions: Group A) No surgery control: eye bulbs were kept at room temperature for 40 min; Group B) Sham surgery: PPV with the sole use of BSS for 40 min; Group C) Cytotoxic control: PPV with BSS infusion (20 min) followed by intravitreal injection of 1H-PFO (contact time: 20 min); Group D) Surgery with residues: PPV with BSS infusion and sequential intravitreal injection of TA, ERM/ILM dye, PFO and SO, with minimal removal of each compound after a specified contact-time (overall duration: 40 min); Group E) Surgery with minimal residues: PPV performed as in group D, but with maximal removal of each compound (overall duration: 40 min). All the experimental procedures were performed at room temperature. Immediately after surgery, the retina was extracted from each eye bulb and samples of 3-mm diameter were prepared. Retinal viability was determined for each sample by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay. A cell viability <70% was considered the cytotoxicity threshold. Kruskal-Wallis test was used to evaluate the differences in retinal viability between groups. No cytotoxicity was detected in retinal samples in groups A, B and E. Samples from eye bulbs that had undergone surgery with minimal removal of residues (group D) and cytotoxic controls (group C) showed high retinal cytotoxicity. The tested conditions indicated that the combined use of TA, ERM/ILM dye, PFO and SO during PPV does not affect retinal cells viability if all the devices are properly removed, whereas the cytotoxicity detected in group D may suggest that the presence and accumulation of the residues of the compounds used intraoperatively could negatively impact retinal viability due to a cumulative and/or synergistic cytotoxic effect between them, supporting the crucial role of an optimal removal of the intraoperative medical devices to ensure a safe vitrectomy to the patient.

Intraocular perfluorodecalin and silicone oil tamponade (double filling) in the management of complicated retinal detachment: functional and anatomical outcomes using small-gauge surgery.

PurposeTo describe the functional and anatomical results of complicated retinal detachment (RD) treated with small-gauge pars plana vitrectomy (PPV) and combined perfluorodecalin and polydimethylsiloxane tamponade (double filling, DF).MethodsRetrospective analysis of consecutive patients with complex RD (severe proliferative vitreoretinopathy, inferior/posterior/giant retinal tears, and traumatic detachments) treated with small-gauge PPV, membrane peeling, and DF at the Department of Ophthalmology at San Gerardo Hospital, Monza, Italy. Main outcome measures included best-corrected visual acuity (BCVA), rates of retinal reattachment, and complications.ResultsThis study included 15 patients with a median follow-up (FU) of 6 months (range 1–22). Three patients with early retinal redetachment under tamponade and FU shorter than 3 months were excluded from the final functional analysis, but they were considered anatomical failure. At the last examination, BCVA improved in 50% of patients and remained stable in 25% of patients and anatomical success was achieved in 73% of eyes, 64% of them without any endotamponade. Three eyes had retinal redetachment after perfluorodecalin/silicone oil exchange because of diffuse proliferative vitreoretinopathy (PVR) and required reoperation to achieve retinal attachment. In eyes with anatomical success, macular pucker was the most frequent long-term complication (27%).ConclusionIn the management of complex RD, small-gauge pars plana vitrectomy, and double filling endotamponade using wide-angle viewing systems was a well-tolerated and effective technique to preserve visual acuity and achieve anatomical success.