Vision loss under silicone oil tamponade

Retinal Toxicity Assessment Following Vitreoretinal Surgery: A Comparison of Silicone Oil and Perfluoropropane Tamponade Using Diopsys® NOVA™

PURPOSE

This 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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Vision loss associated with silicone oil endotamponade in vitreoretinal surgery - a review

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.

Functional and perfusion changes associated with silicone oil tamponade after macula-off rhegmatogenous retinal detachment surgery: an optical coherence tomography angiography/microperimetry study

PURPOSE

The current study utilizes microperimetry and optical coherence tomography angiography (OCTA) to assess the optic nerve head vasculature, retinal microvasculature, and retinal sensitivity before and after silicone oil (SO) removal.

METHODS

This prospective observational case series study involved 30 eyes subjected to silicone oil endotamponade. Microperimetry and OCTA were utilized to assess the vascular density (VD) of the macula and optic nerve head, as well as the retinal sensitivity (RS), of the participants preoperatively and 1 month following SO removal. The correlation between the various parameters of OCTA and microperimetry was evaluated.

RESULTS

There was a significant improvement in the postoperative best-corrected visual acuity (BCVA) (p-value < 0.001) and the postoperative total RS, which was 6.38 ± 2.34 dB as compared to a mean preoperative total RS of 5.04 ± 2.06 dB (p-value < 0.001) and showing a significant increase in all rings. However, there was no significant difference in the pre and postoperative macular VD. On the other hand, there was a significant increase in the postoperative VD of the whole disk and the peripapillary capillary plexus, p-values < 0.001 and 0.002, respectively.

CONCLUSION

The removal of SO resulted in significant improvements in retinal sensitivity, vision, and optic nerve perfusion. However, no significant change was observed in macular VD.

CLINICAL TRIALS

gov Identifier: NCT04928196.

Macular Parameters Change during Silicon Oil Tamponade for Retinal Detachment Surgery

Background and Objectives: To evaluate possible changes in macular thickness parameters during and after silicon oil tamponade and in pars plana rhegmatogenous retinal detachment surgery. Materials and Methods: Our retrospective study included 34 consecutive patients who underwent 23-gauge retinal detachment surgery with silicon oil tamponade. Central macular thickness (CMT), central macular volume cube (CMV) and average macular thickness cube (AVG) were measured by optical coherence tomography (OCT) before rhegmatogenous retinal detachment surgery with silicon oil tamponade during tamponade (seven days, one month and three months after surgery), and one month after silicon oil removal. Results: In our sample, macular parameters CMT, CMV and AVG in patients who underwent retinal detachment surgery were statistically reduced during silicon oil tamponade (p < 0.05). After silicon oil removal, all parameters recovered, reaching numeric values which were not statistically significant compared to preoperative values. The average span of silicon oil tamponade was 162 +/- 23 days. Conclusions: Silicon oil tamponade during 23-gauge rhegmatogenous retinal detachment surgery leads to a transitory reduction of central macular thickness, central macular volume cube and average macular thickness cube in eyes that underwent retinal surgery. After silicon oil removal, macular parameters returned to preoperative values in most of the patients.

A reminder about silicone oil toxicity: three cases over five years in a tertiary hospital

PURPOSE

Presumed silicone oil-related retinal toxicity causes central vision loss with a reported incidence of 1-33% in the first month after oil removal and 10% in the first six months of having silicone oil in-situ. This report examines local rates in a tertiary hospital that manages many geographically distanced patients. A miniature literature review, audit and case series are presented.

METHODS

A retrospective audit of all patients who underwent a 'removal of silicone oil' surgery at the Royal Brisbane and Women's Hospital between 2016 and 2021. Inclusion criteria were that the oil was inserted for primary or recurrent rhegmatogenous retinal detachment. Visual acuity was analysed at presentation, at 1 and 3 months of oil in-situ, preoperatively to removal of oil and up to 6 months after oil removal. Ocular coherence tomographic parameters were examined at each time interval, including nerve fibre layer (NFL) and ganglion cell layer and inner plexiform layer (GCL + IPL) thicknesses in the 3 mm parafoveal zone, presence of inner retinal microcystic changes or intraretinal silicone oil globules. Patients were identified who had unexplained vision loss of two or more Snellen lines. Further analysis and case review were performed.

RESULTS AND CONCLUSIONS

Between January 2016 and May 2021, 101 patients met the inclusion criteria. Three patients had significant and unexplained visual loss. They are presented in this paper. Presumed silicone oil toxicity is an increasingly recognised and potentially devastating phenomenon that vitreo-retinal surgeons should be wary of. Patients should be specifically consented for it and hospitals should perform local auditing to determine their own rates and inform this discussion.

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.

Endophthalmitis at a tertiary referral center: Characteristics and treatment outcomes over three decades

Purpose: To explore the incidence, pathogens, treatment, and prognosis of endophthalmitis.

Methods: Patients who were diagnosed with endophthalmitis from January 1990 to October 2020 at Peking Union Medical College Hospital were retrospectively reviewed and examined. Subgroup analysis was conducted regarding different initial treatment methods for eyes without concurrent retinal detachment (RD) at presentation.

Results: A total of 249 eyes of 233 patients were included in this retrospective study. The most common clinical scenario was exogenous endophthalmitis (60.6%). The most frequent bacteria and fungi were coagulase-negative staphylococci (10.0%) and candida (6.8%), respectively. Retinal with/without choroid detachment was the most common complication after treatment. Patients with endogenous endophthalmitis were more likely to have binocular involvement; there were also more patients with diabetes mellitus or immunosuppressive diseases, and the prognosis of visual acuity (VA) was poorer. There were more eyes with concurrent RD at presentation that underwent serious complications after treatment (p < 0.05), and the visual outcome was worse than that without concurrent RD (p < 0.05). Subgroup analysis was conducted according to different initial treatments in eyes without concurrent RD. Group 1 received pars plana vitrectomy (PPV) with intravitreal injection of antibiotics (IVI) as initial treatment, Group 2 was initially treated with IVI only, and Group 3 was initially treated with nonsurgical treatment. More eyes that initially received IVI alone and nonsurgical treatment required additional treatments, especially additional PPV. VA in both Groups 1 and 2 significantly improved by the final VA. However, there was no significant difference in final VA between the two groups. There was an insignificant trend that serious posttreatment complications were more common in Group 1. In Group 1, 17 eyes received silicone oil or gas tamponade at the same time, whereas 62 did not. Eyes that were initially treated with PPV + IVI while without tamponade needed more additional treatments and additional IVI.

Conclusion: Endophthalmitis is a devastating intraocular disease and requires early intervention. Endogenous endophthalmitis has a poorer visual prognosis than exogenous entity. PPV + IVI as an initial treatment may reduce additional therapy.

[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.

Changes of retinal ganglion cell complex after vitrectomy in rhegmatogenous retinal detachment patients and its correlation with inflammatory blood biomarkers

Purpose

To compare retinal ganglion cell complex (GCC) parameters between rhegmatogenous retinal detachment (RRD) eyes and normal contralateral eyes after vitrectomy and to evaluate their correlation with inflammatory blood markers.

Methods

We investigated 25 eyes that underwent vitrectomy due to RRD. Venous blood samples were collected from all participants before 08:00 a.m. on the second day of admission after a 12-hour fast for blood counts. The differences of retinal structure between RRD and contralateral eyes were compared 1 week postoperatively.

Results

Focal loss volume (FLV) (2.009 ± 1.286)% was significantly increased compared with the contralateral eyes (p <  0.001). Monocyte-to-high-density lipoprotein was significantly positively correlated with GCC thickness parameters, and negatively correlated with FLV and global loss volume (GLV). Postoperative best-corrected visual acuity was negatively correlated with GLV (p = 0.039, R² = 0.172).

Conclusion

Retinal ganglion cells (RGCs) loss might present early postoperatively in RRD eyes, and was associated with systemic inflammation. RGCs loss might affect postoperative vision.

Early Pars Plana Vitrectomy in Acute Endophthalmitis: The Manchester Series

BACKGROUND AND OBJECTIVE

Current literature lacks good-quality evidence regarding the outcomes of early pars plana vitrectomy (PPV) for acute exogenous endophthalmitis. The aim for this study was to analyze and discuss the outcomes of PPV for endophthalmitis in a UK tertiary hospital.

PATIENTS AND METHODS

This study was a retrospective case series. The clinical records of consecutive patients who had PPV for acute exogenous endophthalmitis were reviewed. Demographic data, etiology, timing of onset, timing of PPV, intraand postoperative complications, baseline and final best-corrected visual acuity (BCVA), therapeutic regimens, and microbiology details were collected. Primary efficacy and safety outcome measures were BCVA improvement of two or more logMAR lines and intra- or postoperative complications, respectively.

RESULTS

Forty-one patients with a median age of 76 (interquartile range, 64 to 82) years were studied. The most common etiology was intravitreal injection (41%), followed by phacoemulsification (34%). Median interval to PPV was 1.0 (interquartile range, 1.0 to 3.0) days. In a multivariate model controlling for age, baseline BCVA, microbiology positivity, and etiology (post-intravitreal injection), PPV after 24 hours was seven times more likely to achieve significant BCVA improvement (odds ratio, 7.47; 95% confidence interval, 1.12 to 49.66; P = .038). PPV within 24 hours of presentation was associated with more intraoperative complications.

CONCLUSIONS

Favorable outcomes may be achieved with current antibiotic regimens and PPV for endophthalmitis. The series suggests that an early surgical intervention may be associated with poorer functional outcomes. Tap and inject at presentation, followed by a semi-urgent PPV as required, seems to be a sensible approach. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:96-102.].

Longitudinal evaluation of retinal thickness and OCTA parameters before and following silicone oil removal in eyes with macula-on and macula-off retinal detachments

BACKGROUND

To investigate the longitudinal retinal vascular and structural alterations by using OCTA following successful repair of retinal detachment (RD) by using silicone oil (SO) endotamponade.

METHODS

A prospective cohort study was performed on 24 eyes of 24 subjects; 17 of them with macula-off and seven with macula-on RD. At least four OCTA scans were generated for each study eye; two before and two after SO removal (SOR). At each session, retinal thickness (RT), vascular density (VD) in the superficial (SCP) and deep capillary plexuses (DCP) and foveal avascular zone(FAZ) size were measured within the fovea, parafovea and whole macular image. The changes in repeated measures of the same parameters especially before and after SOR were performed and compared within macula-on and macula-off groups and between fellow eyes.

RESULTS

"In the macula-off eyes, RT measurements within the whole macula, fovea and parafovea reduced as compared with their fellow eyes(p < 0.0001, p = 0.001 and p < 0.0001, respectively) and did not improve after SOR. Additionally, all of the whole macular, foveal, and parafoveal VD measurements at SCP and foveal VD at DCP were less than their fellow eyes after SOR (p = 0.026, p = 0.023 p = 0.026, and p = 0.002, respectively). In macula-on eyes, RT measurements decreased within the parafovea and whole macular area before SOR (p = 0.018 and p = 0.011, respectively) but improved after SOR. Also, VD measurements did not change during follow-up and were not statistically different than their fellow eyes (p > 0.05). FAZ enlargement was found in eyes with macular-off RD after SOR, whereas it was not observed with macular-on RD (p = 0.038and p = 0.237, respectively).

CONCLUSIONS

Treatment of macula-off RD with SO tamponade has been associated with vascular retinal abnormalities which did not improve following SOR. On the contrary, successful treatment of RD with SO tamponade in macula-on eyes VD measurements of SCP and DCP were not statistically different than their fellow eyes.

The effect of silicone oil tamponade on retinal layers and choroidal thickness in patients with rhegmatogenous retinal detachment: a systematic review and meta-analysis

Background

To evaluate the effects of intravitreal silicone oil (SO) on the retinal and choroidal thickness in eyes with rhegmatogenous retinal detachment (RRD).

Methods

A literature search was performed in Web of Science, Scopus, ProQuest, Embase, Clinical Key, Science Direct, Cochrane Library, and Springer, as well as Persian databases, including IranDoc, MagIran, SID, MOH thesis, and MOH articles until June 2020. Two reviewers independently searched and extracted the data.

Results

Sixteen studies (n = 391) met the inclusion criteria. The meta-analysis showed that the SO tamponade could significantly reduce the central macular thickness (CMT) in patients with RRD as compared to gas tamponade WMD = − 14.91; 95% CI: − 22.23, − 7.60; P < 0.001, I² = 71%). No significant change was found in CMT between the eye with SO tamponade (after SO removal) and the fellow healthy eye in patients with RRD (WMD = − 3.52; 95% CI: − 17.63, 10.59; I² = 68.6%). Compared to the preoperative stage, the SO tamponade could significantly reduce the subfoveal choroidal thickness in patients with RRD (WMD = − 18.67, 95% CI: − 30.07, − 1.28; I² = 80.1%). However, there was no significant difference in the subfoveal choroidal thickness before and after SO removal (WMD = − 1.13, 95% CI: − 5.97, 3.71; I² = 87.6%).

Conclusion

The SO tamponade had a significant effect on the reduction of retinal layers and the subfoveal choroidal thickness.

Changes of macular vessel density and thickness in gas and silicone oil tamponades after vitrectomy for macula-on rhegmatogenous retinal detachment

Purpose

To investigate the macular vessel density and thickness in macular-on rhegmatogenous retinal detachment (RRD) after vitrectomy with gas and silicone oil (SO) tamponade.

Methods

Patients with macular-on RRD eyes, treated with a single successful vitrectomy with gas or SO tamponade and a minimum 30 months follow-up, were reviewed. Best-corrected visual acuity (BCVA), macular vessel density and retinal thickness by using optical coherence tomography angiography, were compared to the contralateral eyes.

Results

Sixteen eyes with gas tamponade and 17 eyes with SO tamponade were included in the study. LogMAR best-corrected visual acuity (BCVA) slightly improved from 0.25 ± 0.18 (Snellen 20/36) to 0.17 ± 0.23 (Snellen 20/30) in eyes with gas tamponade, and decreased from 0.30 ± 0.22 (Snellen 20/40) to 0.49 ± 0.28 (Snellen 20/62) in eyes with SO tamponade. The parafoveal vessel densities in superficial vascular complex (SVC) and the corresponding inner retinal thickness (IRT) were similar between the affected eyes and the contralateral eyes in gas tamponade group (P = 0.578, P = 0.943), while significantly reduced in the affected eyes, compared to the contralateral eyes in SO tamponade group (P < 0.001, P < 0.001).

Conclusion

Eyes in SO tamponade group had worse BCVA, lower SVC vessel densities and thinner corresponding IRT after vitrectomy for macular-on RRD, than those in gas tamponade group.

Effectiveness and Safety of Coadministration of Intravitreal Dexamethasone Implant and Silicone Oil Endotamponade for Proliferative Diabetic Retinopathy with Tractional Diabetic Macular Edema

Purpose: To investigate the efficacy and safety of coadministered intravitreal dexamethasone (IVD) implant and silicone oil endotamponade during pars plana vitrectomy (PPV) for the treatment of proliferative diabetic retinopathy (PDR) with tractional diabetic macular edema (DME). Methods: In this prospective, controlled, and randomized clinical study, the eyes with PDR and vitreomacular traction syndrome that underwent PPV with silicone oil endotamponade were divided into 2 groups. Group 1 was defined as the control group, and no other procedures were performed. IVD was implanted to the eyes in Group 2. In both groups, panretinal photocoagulation was completed to the missed areas during PPV. All cases followed for 6 months, postoperatively. Retinal findings were followed with optical coherence tomography and fluorescein fundus angiography. Results: A total of 52 eyes of 52 patients were included in the study. Twenty-six eyes of 23 patients were included in both groups. The improvement in best corrected visual acuity was statistically significantly higher in Group 2 (P > 0.05). In the postoperative period, the DME development rate and intravitreal ranibizumab (IVR) injection requirement were significantly higher in Group 1 (P > 0.05). There was no statistically significant difference in the proliferative vitroretinopathy development rate between the groups (P < 0.05). Conclusion: Coadministration of IVD implant and silicone oil endotamponade to the eyes with PDR during vitrectomy seems to be safe and effective application and may decrease the rate of DME and the requirement of IVR injection.

Unexplained Visual Loss After Silicone Oil Removal: A 7-Year Retrospective Study

Introduction

Unexplained visual loss after removal of silicone oil from the eye has been described. The purpose of this study is to determine the incidence of unexplained loss of visual acuity after SO removal and to provide possible explanations for this phenomenon.

Methods

This retrospective study included patients that underwent vitreoretinal surgery, at Centro Hospitalar São João, between January of 2012 and October of 2018. Inclusion criterion was vitreoretinal surgery in which the chosen endotamponade was SO, followed by removal of SO and exchange with balanced salt solution (BSS) or air. After SO removal, patients with documented loss of best corrected visual acuity (BCVA) on two or more Snellen lines were analyzed and patients in which the cause of the visual loss was identified, namely OHT (intraocular pressure > 21 mmHg), retinal re-detachment, glaucoma, retinal proliferative membrane formation, or corneal decompensation, were excluded. All patients with unexplained visual loss underwent spectral domain optical coherence tomography (SD-OCT) to exclude causes of visual reduction such as cystoid macular edema, epiretinal membrane, or ellipsoid/interdigitation zone disruption. A p value less than 0.05 was considered statistically significant.

Results

A total of 46 eyes underwent SO tamponade and SO removal during the study period. In 34.8% of the cases (n = 16) there was visual acuity loss in at least two Snellen lines. Of 46 eyes, 23.9% (n = 11) showed vision loss due to known secondary causes. Unexplained loss of visual acuity after SO removal occurred in 10.9% of cases. OHT during silicone endotamponade (p = 0.046) and silicone emulsification (p = 0.001) were identified as factors associated with unexplained visual loss after SO removal.

Conclusion

Unexplained loss of visual acuity after SO removal occurred in 10.9% of cases. OHT during silicone endotamponade and SO emulsification were identified as important factors in the ethology of this phenomenon.

Optical coherence tomography angiography changes in macula-off rhegmatogenous retinal detachments repaired with silicone oil

PURPOSE

To evaluate the changes on optical coherence tomography angiography (OCTA) in macula-off rhegmatogenous retinal detachments (RRD) treated with pars plana vitrectomy (PPV) and silicone oil (SO) 5000-cSt tamponade.

MATERIALS AND METHOD

Forty-five eyes with macula-off RRD treated with PPV and SO tamponade were enrolled with the fellow eye being used as a control. OCT-A was obtained using the RTVue XR 100 Avanti (Optovue, Inc., Fremont, CA, USA) at the 1-week, 1-month, and 3-month postoperative visit. Retinal vascular density, choroidal flow area, retinal thickness, and foveal avascular zone area were evaluated at each follow-up visit. Changes in these parameters in the postoperative eye were tracked at each follow-up visit as were the relative differences between the postoperative eye and the contralateral eye.

RESULTS

Vascular density of parafoveal superficial capillary plexus and total retina demonstrated significant decrease in the postoperative silicone-filled eye when compared to the fellow eye (P < 0.0001). Although there was some improvement in these values at subsequent follow-ups, they remained less than the fellow eye. Foveal (P = 0.002) and parafoveal (P < 0.0001) thickness were less than the fellow eye. Choroidal flow area did not show a significant change in operated eye compared with the fellow eye.

CONCLUSION

Eyes with macula-off RRD repaired with PPV and SO, at 3-month follow-up, demonstrated less retinal vascular density at parafoveal area as well as lower retinal thickness at fovea when compared to the healthy fellow eyes.

Central posterior lens capsule used instead of inverted ILM flap: a clinic-pathological case report

PURPOSE

To present immunocytochemical characterization of a surgically excised central posterior lens capsule (PLC) that was transplanted to close a secondary refractory full-thickness macular hole (FTMH) as an epiretinal flap. For comparison, tissue of both an unaffected internal limiting membrane (ILM) and unexposed PLC was processed.

METHODS

Clinical-pathological case report.

RESULTS

We report of a 38-year-old patient who underwent pars plana vitrectomy (PPV) with PLC tissue for patching secondary FTMH and silicone oil tamponade after tractional retinal detachment. The PLC was peeled off during a vitrectomy one year after positioning. For immunocytochemistry, the removed PLC was prepared as flat-mount and showed a positive immunofluorescence of the Müller cells marker glutamine synthetase (GS) and for vimentin. The microglia marker IBA and the neuroprotective neurotrophic marker glia cell-derived neurotrophic factor (GDNF) were tested positive, too. There was no immunoreactivity of cellular retinaldehyde-binding protein (CRALBP) and glial fibrillary acidic protein (GFAP). In comparison, tissue of a control ILM that was obtained during standard FTMH surgery showed few single cells that were likewise positive for GS, GDNF and IBA. The control specimen of unexposed PLC showed rarely cells that were without positive immunostaining for the tested markers.

CONCLUSION

Our analysis revealed positive immunoreactivity of macro- and microglia cells of PLC tissue that was used to patch a refractory FTMH. Similar immunostaining of PLC material and ILM suggests the PLC transplantation as an alternative treatment option for refractory FTMH.

Emulsified silicone oil is taken up by and induces pro-inflammatory response in primary retinal microglia

Purpose

Silicone oil is used as endotamponade in combination with vitrectomy. Thinning of retinal layers and loss of retinal cells under silicone oil use have been found. Here, we investigate the influence of silicone oil on primary microglia cells.

Methods

Primary microglia cells were prepared from the porcine retina. Microglia identity was assessed with Iba1 staining. Silicone oil was emulsified by sonification. Cell morphology and silicone oil uptake were evaluated by light microscopy after Coomassie blue staining. Cytokine secretion was evaluated with ELISA. Toxicity of silicone oil on microglia and toxic effect of silicone oil–treated microglia on neuronal cell line PC12 were evaluated by MTT or WST assay, respectively.

Results

Microglia took up silicone oil droplets after 72 h of incubation. Silicone oil induced no toxicity but increased the metabolism in microglial cells. In addition, the secretion of IL-6 and IL-8, but not of IL-1ß or TNF-α, was induced. Silicone oil–treated microglia did not exert any neurotoxic effect on differentiated PC12 cells but induced an increase in metabolism.

Conclusion

Emulsified silicone oil changes the activity level of microglia and induces the secretion of IL-6 and IL-8. Neurotoxicity is not induced. Further experiments are required to investigate the long-term effect of silicone oil on microglia and their consequent effect on neuronal cells.

Foveal Microvascular Structures in Eyes with Silicone Oil Tamponade for Rhegmatogenous Retinal Detachment: A Swept-source Optical Coherence Tomography Angiography Study

Silicone oil (SO) is widely used as a long-term intravitreal tamponading agent for rhegmatogenous retinal detachment (RRD) repair. This study investigated the structural changes of the foveal microvasculature using optical coherence tomography angiography (OCTA) in patients with RRD treated with vitrectomy and SO tamponade. Thirty-eight patients with unilateral RRD who were treated with vitrectomy and SO tamponade and were followed up for ≥3 months after SO removal were included. En face OCTA images were obtained and foveal avascular zone (FAZ) area and vascular density (VD) were compared between study eyes and unaffected contralateral eyes. The FAZ area in deep capillary plexus (DCP) was larger (P < 0.001) and the VD in DCP was lower (P = 0.022) in the study eyes than in the fellow eyes. The duration of SO tamponade was significantly correlated with the enlargement of FAZ area (P = 0.034) and reduction of VD in DCP (P = 0.015). These changes could reflect vascular insufficiency in eyes with SO tamponade and may represent a potential explanation for the pathogenesis of retinal thinning and unexplained visual loss.

Silicone Oil Tamponade in Rhegmatogenous Retinal Detachment: Functional and Morphological Results

Purpose: To evaluate the functional and morphological outcomes of patients with SO tamponade due to primary rhegmatogenous retinal detachment (primRD) and recurrent rhegmatogenous detachment (recRD).Methods: Seventy-five eyes were enrolled in this prospective study between January 2009 and December 2016. Patients with primRD and recRD were evaluated in a complete ophthalmic examination including best-corrected visual acuity (BCVA) and OCT before and after silicone oil removal (SOR).Results: The primRD group comprised 35 eyes and the recRD group 40 eyes with a duration of SO tamponade of 9 ± 4/12 ± 11 months in the primRD/recRD groups (p = .088). The preoperative OCT revealed a high rate of morphological changes such as ERM (primRD: 24%; recRD: 69%) and CME (primRD: 10%; recRD: 55%) in the recRD compared with the primRD group (ERM: p = .18; CME: p = .04). No such difference was observed postoperatively. Disruption of the ellipsoid zone (EZ) was similar in both groups (primRD: 52%; recRD: 72%) before SOR and was restored in 66%/58% (primRD/recRD) after SOR. No difference was found regarding pre- and postoperative VA (0.91 ± 0.54/0.90 ± 0.54logMAR primRD/recRD preoperative; 0.76 ± 0.56/0.71 ± 0.53logMAR primRD/recRD at the last follow-up; p = .96/p = .70). EZ integrity (0.43 ± 0.31logMAR) was associated with better functional results than an interrupted EZ (0.86 ± 0.43logMAR; p < .001). A significant positive correlation of the duration of SO tamponade and the final VA was found in the primRD (r = 0.396, p = .02) whereas none in the recRD group (r = 0.196; p = .31).Conclusion: Morphological changes including ERM and CME were more pronounced in the recRD group, but only before SOR. Interestingly, the pre- and postoperative BCVA were similar in both groups with EZ integrity being a factor of good functional outcome. The duration of SO tamponade had a statistically significant negative impact on the postoperative VA in the primary detachments.

Silicone oil-associated retinal light exposure under a surgical microscope

PURPOSE

Based on the hypothesis that silicone oil (SO) with a higher refractive index than water induces unexpected vignetting effects during surgeries, we aimed to investigate the relationship between the volume of SO and light intensity using a surgical microscope.

METHODS

Using a light-sensitive paper and model eye filled with varying volumes (0%, 50%, 62.5%, 75%, 87.5% and 100%) of SO, the light intensity of intraocular lens (IOL) with various refractive powers (0, 10 and 20 dioptres) illuminated by a surgical microscope was measured.

RESULTS

Light exposure density with 1.0% coaxial and oblique light was approximately 22-fold higher than that with 0.1% coaxial and oblique light. Further, it was approximately 34-fold higher in eyes with +20 D IOL than in those with no IOL. The density in eyes with 75% SO was the highest among all groups followed by that with 0% SO. Light exposure densities in the eyes with 75% and 0% SO were significantly higher than those with other volumes of SO. In SO-filled eyes, a microscope set with only an oblique light and a filter successfully reduced light exposure.

CONCLUSION

Silicone oil-related vision loss (SORVL) during SO removal surgeries might be due to increased light exposure on the macular retina caused by the SO-associated vignetting effect. SORVL could be prevented by placing a filter in the microscope during SO removal surgeries.

Retinal Sensitivity before and after Silicone Oil Removal Using Microperimetry

The purpose of the study is to assess the retinal sensitivity, using microperimetry, before and after silicone removal. It included 22 patients admitted for silicone removal after vitrectomy for macula-off retinal detachment. Patients were divided into 2 groups according to the duration of silicone tamponade: Group A: <3 months (included 10 patients), and Group B: 3–6 months (included 12 patients). Retinal sensitivity was tested, using microperimetry, one day before and one month after silicone removal. The best-corrected visual acuity (in LogMAR) significantly improved postoperatively (0.69 versus 1.06 and 0.69 versus 1.07 in Groups A and B, respectively). The mean intraocular pressure (IOP) was 12.89 ± 1.05 mmHg postoperatively versus 14.89 ± 1.76 mmHg preoperatively in Group A (p=0.011) and was 13.33 ± 1.30 mmHg postoperatively versus 15.33 ± 3.11 mmHg preoperatively in Group B (p=0.008). In Group A, the mean postoperative overall retinal sensitivity was 8.70 ± 2.56 dB versus 5.68 ± 2.00 dB preoperatively (p=0.008). In Group B, it was 9.83 ± 3.36 dB versus 7.00 ± 2.55 dB (p=0.002). No statistically significant difference was found between the two groups as regards improvement in overall retinal sensitivity. We concluded that the overall retinal sensitivity significantly increased following silicone removal in both groups. This trial is registered with ISRCTN43187564.

Macular Changes on Optical Coherence Tomography Before, During, and After Silicone Oil Tamponade for Macula-On Retinal Detachment: A Case Series

Purpose:

Assess changes on spectral domain optical coherence tomography (OCT) before, during, and after removal of silicone oil (SO).

Methods:

Retrospective series of patients who underwent SO tamponade for macula-on rhegmatogenous retinal detachment. OCT scans of the affected eye were taken before, during, and 3 months after SO tamponade. Qualitative assessment of foveal contour and quantitative comparison of OCT parameters (central macular, cube, ganglion cell layer [GCL], and outer retinal thicknesses) were done between 3 time points.

Results:

Ten eyes of 9 patients were included. Flattening of the foveal contour during SO tamponade was completely reversed after SO removal. Average cube and GCL thicknesses decreased with SO tamponade and increased after SO removal ( P = .01 and P = .02, respectively). Outer retinal thicknesses did not vary among 3 time points ( P = .09).

Conclusions:

SO tamponade causes foveal flattening and thinning of the inner retinal layers, which is reversible on removal.

Final anatomic and visual outcomes appear independent of duration of silicone oil intraocular tamponade in complex retinal detachment surgery

AIM

To report anatomic and visual outcomes following silicone oil removal in a cohort of patients with complex retinal detachment, to determine association between duration of tamponade and outcomes and to compare patients with oil removed and those with oil in situ in terms of demographic, surgical and visual factors.

METHODS

We reported a four years retrospective case series of 143 patients with complex retinal detachments who underwent intraocular silicone oil tamponade. Analysis between anatomic and visual outcomes, baseline demographics, duration of tamponade and number of surgical procedures were carried out using Fisher's exact test and unpaired two-tailed t-test.

RESULTS

One hundred and six patients (76.2%) had undergone silicone oil removal at the time of review with 96 patients (90.6%) showing retinal reattachment following oil removal. Duration of tamponade was not associated with final reattachment rate or with a deterioration in best corrected visual acuity (BCVA). Patients with oil removed had a significantly better baseline and final BCVA compared to those under oil tamponade (P=0.0001, <0.0001 respectively).

CONCLUSION

Anatomic and visual outcomes in this cohort are in keeping with those reported in the literature. Favorable outcomes were seen with oil removal but duration of oil tamponade does not affect final attachment rate with modern surgical techniques and should be managed on a case by case basis.

Outer Retinal Changes on Spectral-Domain Optical Coherence Tomography Pre- and Post-Silicone Oil Removal

BACKGROUND AND OBJECTIVE

To evaluate outer retinal changes present on spectral-domain optical coherence tomography (SD-OCT) in eyes pre- and post-silicone oil (SiO) removal (SOR).

PATIENTS AND METHODS

Retrospective case series of patients who underwent pars plana vitrectomy with SiO instillation and had SD-OCT completed pre- and post-SOR. SD-OCT parameters included presence of subretinal fluid, epiretinal membrane, ellipsoid zone disruption (EZD), external limiting membrane disruption, central subfield thickness (CST), and choroidal thickness. Visual acuities (VAs) and duration of SiO instillation were recorded.

RESULTS

Thirty eyes of 30 patients were included. Mean Snellen VA pre- and post-SOR was 20/762 and 20/206, respectively (P < .001). Eyes with EZD under SiO had significantly longer duration of SiO tamponade (P = .029) along with worse VA post-SOR (P = .002). EZD was noted in 20 eyes with SiO and only 10 eyes post-SOR. Of these 10 eyes with resolution of EZD post-SOR, mean VA was significantly better (Snellen equivalent 20/133) compared to eyes with persistent EZD (Snellen equivalent 20/513; P = .01). CST and choroidal thickness decreased post-SOR (P = .117, P = .07).

CONCLUSION

Outer retinal abnormalities on SD-OCT in SiO-filled eyes may improve in some patients following SOR. Some changes may be related to duration of SiO tamponade. EZD in SiO-filled eyes may portend a worse clinical outcome post-SOR despite surgical success. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:978-982.].