Heavy silicone oil and intraocular inflammation.

In the past two decades, many advances have been made in vitrectomy instrumentation, surgical techniques, and the use of different tamponade agents. These agents serve close retinal breaks, confine eventual retinal redetachment, and prevent proliferative vitreoretinopathy (PVR). Long-acting gases and silicone oil are effective internal tamponade agents; however, because their specific gravity is lower than that of the vitreous fluid, they may provide adequate support for the superior retina but lack efficacy for the inferior retina, especially when the fill is subtotal. Thus, a specific role may exist for an internal tamponade agent with a higher specific gravity, such as heavy silicone oils (HSOs), Densiron 68, Oxane HD, HWS 45-300, HWS 46-3000, and HeavySil. Some clinical evidence seems to presume that heavy tamponades are more prone to intraocular inflammation than standard silicone if they remain in the eye for several months. In this review, we discuss the fundamental clinical and biochemical/molecular mechanisms involved in the inflammatory response after the use of heavy tamponade: toxicity due to impurities or instability of the agent, direct toxicity and immunogenicity, oil emulsification, and mechanical injury due to gravity. The physical and chemical properties of various HSOs and their efficacy and safety profiles are also described.

Anti-TNF therapy for juvenile idiopathic arthritis-related uveitis.

Juvenile idiopathic arthritis-related uveitis is the most common type of uveitis in childhood and one of the main causes of visual impairment in children. The introduction of biological treatment has widened the range of therapeutic options for children with uveitis refractory to standard nonbiologic immunosuppressants. Data from clinical trials suggest that both adalimumab and infliximab have demonstrated effectiveness and safety in open-label studies, although no large, randomized, controlled trials have been reported so far. The role of etanercept in treating juvenile idiopathic arthritis-related uveitis is not yet well defined. In our experience, anti-tumor necrosis factor therapy has been shown to be more effective than steroids and/or methotrexate in treating uveitis. Up to now, tumor necrosis factor blocking compounds have been reserved for the treatment of the most severe cases of refractory uveitis, and larger prospective clinical trials are required in order to better assess the safety of these new compounds.

Systemic thromboembolic adverse events in patients treated with intravitreal anti-VEGF drugs for neovascular age-related macular degeneration.

INTRODUCTION: The consistent association between choroid neovascularization (CNV) and increased VEGF-A expression provides a strong reason for exploring the therapeutic potential of anti-VEGF agents in the treatment of neovascular age-related macular degeneration (AMD). The authors report the systemic side effects secondary to intravitreal administration of these compounds, that is, the main cardiovascular effects, as well as the less frequent cerebrovascular accidents, myocardial infarction, transient ischemic attacks, deep vein thrombosis, pulmonary embolism and thromboflebitis. AREAS COVERED: The authors reviewed major Clinical Trials and publications concerning systemic adverse events of anti-VEGF drugs in order to identify the main thromboembolic events related to the use of these agents and their occurrence. Anti-VEGF efficacy, safety and tolerability are also discussed. EXPERT OPINION: Three compounds (pegaptanib, ranibizumab and aflibercept) have been approved for the treatment of AMD; a fourth agent, bevacizumab, is used off-label. Anti-VEGF therapy has not shown the ability to fully eradicate the CNV, so that recurrences are common when the intravitreal injections are suspended. Although no evident rise in anti-VEGF-induced thromboembolic side effects was reported, more data are required to evaluate hemodynamic and pharmacokinetics of these compounds. Since only few studies have focused on these aspects, further researches are mandatory to determine distribution, effects and duration of these substances.

Systemic adverse drug reactions secondary to anti-VEGF intravitreal injection in patients with neovascular age-related macular degeneration.

The wet form of age related macular degeneration (AMD), known also as exudative or neovascular, is characterized by the formation of a pathological choroidal neovascular membrane (CNV) responsible for most cases of severe blindness. Vascular endothelial growth factor (VEGF) is a homodimeric glycoprotein acting as a growth factor selective for endothelial cells; it regulates angiogenesis and enhances vascular permeability and plays a leading role in this disorder. The consistent association between CNV and increased VEGF-A expression provides a strong reason for exploring the therapeutic potential of anti-VEGF agents in the treatment of neovascular AMD. The importance of VEGF for the development of AMD-related CNV has led to the development of a strategy able to block its pathologic effects. The rationale is that a blockade of VEGF actions could be effective in arresting choroidal angiogenesis and also reducing the vascular permeability, which is frequently the main cause of visual acuity deterioration. However, VEGF has also important functions in vascular physiology. The effects of anti-VEGF therapy may inhibit these functions. Herein we report the systemic adverse events secondary to intravitreal administration of these compounds i.e. the main cardiovascular effects (thrombosis, hemorrhage, hypertension, proteinuria), as well as the less frequent cerebrovascular accidents, myocardial infarction, transient ischemic attacks, deep vein thrombosis, pulmonary embolism and thrombophlebitis.