Clinical Trial: Strategies for Management of Corneal Neovascularisation

Study Status: Not yet recruiting
Recruit Status: Not yet recruiting
Study Type: Interventional

Official Title: Management of Active and Established Corneal Neovascularisation to Prevent Visual Impairment

Brief Summary:

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.


Detailed Summary:

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.


Sponsor: University of Nottingham

Current Primary Outcome: Decreased corneal neovascularisation [ Time Frame: 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.


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Improved/maintained Snellen's visual acuity [ Time Frame: 10 months ]
    Visual acuity is assessed using Snellen chart and vision is expressed in LOGMAR units
  • Decreased corneal opacity related to lipid deposition [ Time Frame: 10 months ]
    The response to treatment will be judged clinically by biomicroscopy examination and quantitatively by comparison with pre-treatment slit lamp photographs. The comparison of the pre and post treatment slit lamp images will be done by two independent blind reviewers.
  • Reduced episodes of graft rejection(in corneal graft patients) [ Time Frame: 10 months ]
    Number of rejection episodes will be recorded


Original Secondary Outcome: Same as current

Information By: University of Nottingham

Dates:
Date Received: October 27, 2015
Date Started: December 2015
Date Completion: August 2018
Last Updated: December 1, 2015
Last Verified: December 2015