Management of Active and Established Corneal Neovascularisation to Prevent Visual Impairment
试验速览
- 阶段
- 4 期
- 入组人数
- 40
- 主要终点
- Decreased corneal neovascularisation
研究概览
简要总结
The cornea is the transparent window of the eye, which allows light to enter into the eye and also contributes to the focusing of the light rays. One of the major factors responsible for its transparency is the lack of blood vessels. However, following inflammation new blood vessels (corneal vascularisation [CVas]) grow into the cornea affecting its transparency and impairing vision. CVas leads to further damage in the form of scarring,oedema,fat deposition and is a major cause of corneal graft rejection.
In 2000 with ethical approval (OY129801) the investigators developed and published a clinical technique called Fine Needle Diathermy occlusion of corneal vessels (FND). This has proven very successful for occluding established vessels and is practiced in many centers across the world. Recently it has been demonstrated that by inhibiting a chemical stimulant of vessel formation called vascular endothelial growth factor(VEGF) active new vessel growth in the retina can be suppressed. The approach is also being used for corneal new vessels. Bevacizumab (Avastin) is a chemical inhibitor of VEGF and is used extensively to treat retinal new vessels in macular degeneration. Avastin has been shown to be effective and safe in treating corneal new vessels. The investigators propose to evaluate the efficacy and safety of FND alone and FND combined with Avastin in treatment of CVas.
详细描述
Corneal neovascularisation is a very common problem affecting both sexes at all ages and induced by differing underlying causes. It is considered to be the single most important risk factor for graft rejection. The process of angiogenesis, i.e. the formation of new blood vessels, is similar in any part of the body. Hence principles adopted to alleviate new blood vessels in one area can be applied to blood vessels in other areas using similar drugs.
Over the past 8 years a component necessary for angiogenesis, i.e Vascular endothelial growth factor (VEGF) has been targeted to induce regression of blood vessels in patients with cancer with an intravenous dosage of an anti-VEGF.
More recently, anti-VEGF therapies have targeted eye related neovascularisation, especially in the treatment of age related macular degeneration. This role has been expanded to include all other structures in the eye affected by angiogenesis such as neovascular glaucoma(Iris) and diabetic retinopathy(Retina).
Over the past few years attention has been drawn to the use of antiVEGF therapies to the surface of the eye. Many reports in international peer reviewed literature have commented on the use of anti VEGF therapy in the form of drops or injections on the surface of the eye, subconjunctivally and within the cornea. They have found drops and injections are safe, although injections appear to act more favourably. Avastin has been investigated for treating corneal new vessels and was proved to be both safe and effective.
Fine needle diathermy (FND) is a routine method for occluding corneal vessels that was developed in our department in 2000 and is used worldwide. It has been established that this technique is suitable for active and mature vessels.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Patients over the age of 18
- •Able to give informed consent
- •With corneal neovascularisation non responsive or not suitable for conventional steroid therapy
- •Use of effective contraception in females of childbearing age
排除标准
- •Patients under 18 years of age
- •Patients unable or refusing to provide informed consent
- •Patients who are needle phobic
- •Pregnant women, women aiming for conception and breastfeeding women
- •Patients with hypersensitivity to the active substance or to any of the excipients
- •Patients with active or suspected ocular or periocular infections.
- •Patients with active severe intraocular inflammation.
- •Patients with raised intraocular pressure or on glaucoma medication
研究组 & 干预措施
Fine needle Diathermy
Fine needle Diathermy(FND) will be applied under topical anaesthesia under an operating microscope. This involves the insertion of a fine corneal suture needle in the vicinity of the vessels and using this as an extension of the probe of a monopolar cautery to deliver the energy in the corneal tissue at the site at which it is required to occlude the vessels.
干预措施: Fine Needle Diathermy (Device)
Fine Needle Diathermy and Bevacizumab
Fine needle Diathermy(FND) will be applied under topical anaesthesia under an operating microscope. This involves the insertion of a fine corneal suture needle in the vicinity of the vessels and using this as an extension of the probe of a monopolar cautery to deliver the energy in the corneal tissue at the site at which it is required to occlude the vessels. Patients will receive subconjunctival injections of bevacizumab in the conjunctiva near the limbus in the quadrant(s) affected (total volume of between 0.2 ml-0.3 ml of the 2.5 mg/0.1 ml solution). The subconjunctival injections will be administered after FND in the same treated quadrants.
干预措施: Bevacizumab (Drug)
结局指标
主要结局
Decreased corneal neovascularisation
时间窗: 6 months
A comparison of total vascularisation of the corneal area as measured by our grading system (Faraj LA et al, 2015) before and after treatment.
次要结局
- Reduced episodes of graft rejection(in corneal graft patients)(10 months)
- Improved/maintained Snellen's visual acuity(10 months)
- Decreased corneal opacity related to lipid deposition(10 months)