TRActional DIabetic reTInal detachment surgery with co-adjuvant intravitreal dexamethasONe implant: the TRADITION STUDY.

AIM: Main failure of diabetic tractional retinal detachment (TRD) surgery is the development of proliferative vitreoretinopathy (PVR), causing higher re-detachment rates. We investigated whether the use of dexamethasone (DEX) implant at the end of pars plana vitrectomy (PPV) with silicone oil tamponade might have an impact on these outcomes. DESIGN: Comparative, nonrandomized, retrospective study. PARTICIPANTS: A total of 148 eyes from 148 patients that underwent PPV with silicone oil tamponade for diabetic TRD (with DEX implant, n = 52; without DEX implant, n = 96). METHODS: Consecutive patients' records were reviewed for time between TRD diagnosis and surgery; lens status before surgery and after 6, 12, and 24 months; retina attachment rate after primary PPV; change in postoperative PVR severity; rate of re-detachment at 6, 12, and 24 months; use of IOP lowering treatment after 6, 12, and 24 months; surgery details; intra- and postoperative complications. Correlations between outcome measures, postoperative PVR severity, and re-detachment rates were analyzed. MAIN OUTCOME MEASURES: Change in postoperative PVR severity and retinal re-detachment rates with and without the adjuvant use of DEX implant. RESULTS: Retinal re-detachment rates were significantly higher in the group of patients that did not receive DEX implant [11/96 (11.5%) vs. 0/52 (0%), p = 0.049; 11/84 (12.9%) vs. 4/52 (7.7%), p = 0.007; 14/71 (19.7%) vs. 5/52 (10%) p < 0.001 at 6, 12, and 24 months, respectively]. PVR severity correlated with retinal status at 12 and 24 months (p = 0.018 and p = 0.027, respectively). The difference in PVR severity between the two groups was statistically significant at 6, 12, and 24 months (p < 0.001). CONCLUSIONS: DEX implant at the end of PPV in patients with diabetic TRD improves PVR severity and decreases re-detachment rates. This should be considered as an option in the customized treatment of TRD.

Optic Nerve Sheath Fenestration for Treatment of Retrolaminar Silicone Oil Migration.

The authors report the case of a 75-year-old man with preexisting glaucoma and recurrent retinal detachment who underwent intraocular silicone oil placement OD resulting in subsequent retrolaminar silicone oil migration to the optic chiasm and vision loss OS. MRI showed silicone oil tracking posteriorly along the right optic nerve to the chiasm. He was placed on high-dose corticosteroids and underwent a successful optic nerve sheath fenestration with improvement of vision in the contralateral eye. Clinicians should be cognizant of the potential for translaminar posterior migration of intraocular silicone oil, as well as the utility of optic nerve sheath fenestration to decompress the anterior visual pathways and restore vision.

Cytokine profiling in the sub-silicone oil fluid after vitrectomy surgeries for refractory retinal diseases.

Silicone oil (SO) is an intraocular surgical adjuvant that reduces the surgical complications in refractory retinal diseases, although membrane and cellular proliferation is often seen even in SO-filled eyes. We hypothesised that the fluid in the space between the SO and the retina, named the "sub-silicone oil fluid (SOF)", enhances these biological responses. We proposed a safe method for SOF extraction. We also analysed inflammatory cytokine expressions and SOF osmotic pressures from eyes with rhegmatogenous retinal detachment (RRD), proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR) and macular hole-associated retinal detachment (MHRD). Interleukin (IL)-10, IL-12p40, IL-6, monocyte chemotactic protein-1, and vascular endothelial growth factor (VEGF) in the SOF with PVR were significantly higher than in those with RRD or MHRD. Fibroblast growth factor-2, IL-10, IL-12p40, IL-8, VEGF, and transforming growth factor beta 1 levels in eyes with exacerbated PDR indicated a significantly higher expression than those with simple PDR. IL-6 and tumour necrosis factor alpha in eyes with exacerbated PVR demonstrated a significantly higher expression than in those with simple PVR. However, there was no difference in SOF osmotic pressure between group of each disease. These studies indicate that disease-specific SOF is a significant reflection of disease status.

The use of silicone oil-RMN3 (Oxane HD) as heavier-than-water internal tamponade in complicated inferior retinal detachment surgery.

BACKGROUND: Conventional silicone oil provides suboptimal support of the inferior retina. In this study we evaluated the efficacy of Oxane HD in the management of complex retinal detachments involving lower quadrants of the retina. METHODS: A prospective, interventional, comparative study. Eighteen patients were recruited. Treatment outcomes were compared with a historical control group of 14 patients. Patients with grade C3 PVR or greater and inferior retinal breaks, recurrent inferior retinal detachments (with or without PVR) and giant retinal tears were included. In those patients who re-detached under heavy silicone oil (n = 4), retro-oil epiretinal membranes (ERMs) were obtained at the time of subsequent surgery to analyse the immunopathological response to oxane HD. Immunohistochemistry was used to detect glia, retinal pigment epithelium cells (RPE), macrophages, T lymphocytes, or neural elements in the tissue using well-characterised monoclonal antibodies. RESULTS: Retinal attachment of the posterior pole following removal of silicone oil was achieved in 66.6% of the treatment group (n = 12) and 64.3% of controls (n = 9) (p = 1.0). Post-operative PVR developed in five patients in the treatment group (27.8%) and five control patients (35.8%). Following removal of silicone oil, residual oil was observed in 27.8% of the treatment group and 7.1% of controls. Median visual acuity, 3 months following removal of silicone oil, was 2.0 (IQR 0.9-2.0) in the treatment group and 1.0 (IQR 0.6-1.8) in the control group. Complications in the treatment group included, hypotony (n = 3), uveitis (n = 2), glaucoma (n = 1). All ERMs analysed demonstrated microscopic appearances typical of PVR. The membranes were fibrocellular in nature, contained RPE and glial cells, and variable amounts of intracellular and extracellular pigment. In addition, all had a dense infiltrate of vacuolated (presumed oil-filled) macrophages. CONCLUSION: We failed to observe an advantage following the use of Oxane HD in the treatment of inferior retinal detachments. Moreover, Oxane HD was difficult to remove and was associated with a higher incidence of complications.

The history of injectable silicone fluids for soft-tissue augmentation.

BACKGROUND: The debate over the legitimacy of silicone as a safe tool for soft-tissue augmentation has spanned well over half a century. Proponents concede that injections of questionable purity and/or of massive quantities have produced unfavorable outcomes. They assert that in experienced hands with "injectable-grade" silicone, there are very few problems. Despite these claims, the literature is replete with disastrous outcomes following silicone fluid injection, often many years after the initial treatment. METHODS: An extensive review of the English-language literature was conducted using MEDLINE. RESULTS: A comprehensive review of injectable silicones was completed, revealing the origins, misuses, early clinical trials, and support for and against the injection of silicone fluids for the augmentation of soft tissues. CONCLUSIONS: A better understanding of the history of injectable silicone fluids for soft-tissue augmentation can give insight into the pitfalls and complications surrounding its use. There has been an evolution in the technique and type of products used for soft-tissue augmentation. In its current use, silicone oil for permanent soft-tissue augmentation could be a very powerful tool. There is some literature that supports the use of a small amount of purified, high-viscosity silicone oil; however, there has not been a single longitudinal study to date with appropriate follow-up data. The unanswered question remains: Are the risks worth the potential benefits of silicone oil as a permanent filler?

A pilot study on the use of a perfluorohexyloctane/silicone oil solution as a heavier than water internal tamponade agent.

AIMS: To report a prospective two centred non-comparative interventional pilot study of a solution of perfluorohexyloctane and silicone oil (Densiron-68) as a heavier than water internal tamponade. METHODS: 42 consecutive patients were recruited. The indications include proliferative vitreoretinopathy, retinal detachments arising from inferior retinal breaks, and inability to posture. RESULTS: The success rate with one operation using Densiron was 81% and with further surgery 93%. At the end of the study all tamponade agents were removed in 90% of patients. Visual acuity improved from mean logMAR of 1.41 (SD 0.64) to 0.94 (SD 0.57), p = 0.001. There was little evidence of dispersion and excessive inflammation. CONCLUSION: This new tamponade agent is being compared to conventional silicone oil in a prospective international randomised trial.

Investigation of silicone oil and fumed silica in an adjuvant animal model.

Human adjuvant disease is the label given to a syndrome that resembles a connective tissue disease such as scleroderma and that has been hypothesized to follow augmentation mammoplasty with silicone gel implants or silicone with adulerants. To date, there is no proof that pure silicone is the cause of these symptoms. The cases presented in the literature suggest a comparison to the events seen in the rat adjuvant arthritis model. Male Lew/SsN rats (n = 65) were used. To evaluate both the adjuvant and antigenic properties of the gel implant, variations of the standard Freund's complete adjuvant inoculum were prepared. Tested were the abilities of low molecular weight silicone to act as an adjuvant and for fumed silica to act as an antigen by modifying a rat adjuvant arthritis model to include silicone and fumed silica. On day 0, 0.25 ml of each inoculum was injected intradermally into the plantar aspect of the hindfoot of each rat. The foot diameter was recorded at each time period, compared with the contralateral hindfoot, and normalized to controls at regular time periods over the course of 120 days. Silicone oil did not act as an adjuvant. Furthermore, fumed silica alone did not act as an antigen; however, it is capable of eliciting a reaction that is both delayed and uncharacteristic of the rat adjuvant arthritis model. These results indicate that "human adjuvant disease" may be inappropriate and misleading.

The effect of silicone-gel on the immune response.

Silicone materials have been used in medical applications for at least 30 years. Despite this long history of use the question whether silicones can mediate an immunological reaction that may be detrimental to the host remains unanswered. Most studies on the biocompatability of silicones conclude that silicones are chemically stable compounds, which however are often capable of eliciting a benign chronic inflammatory response. Recently, our laboratory has conducted a series of animal experiments aimed at determining the immunological adjuvancy potential of silicone-gel taken from commercial breast implants. Our previous studies have indicated that silicone-gel is a potent humoral (antibody) adjuvant. Our present studies have found that silicone-gel is capable of eliciting auto-antibodies to rat thyroglobulin and bovine collagen II. However this immune response did not produce any histological evidence of thyroiditis or arthritis. Theories to explain why silicone-gel behaves as an adjuvant are discussed along with discussion of the hypothesis on the desirability of replacing silicone-gel with a more hydrophilic material in bioimplants.