Niraimozhi, R (2011) Clinical study on effect of subconjunctival injection of bevacizumab on corneal neovascularization. Masters thesis, Madras Medical College, Chennai.
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Abstract
The cornea has the unique feature of being normally avascular except for small loops which invade the periphery for about 1mm. But under pathologic conditions vessels invade the cornea from the limbal vascular plexus. A wide variety of insults including infection, inflammation, ischemia, degeneration, trauma, and loss of the limbal stem cell barrier can cause corneal neovascularization. Although corneal NV can occasionally serve a beneficial role in the clearing of infections, wound healing, and in arresting stromal melts, its disadvantages are numerous. Corneal NV often leads to tissue scarring, Oedema, lipid deposition, and persistent inflammation that may significantly alter visual acuity. Corneal NV accompanies the most common causes of corneal infectious blindness in both the developed (herpetic keratitis) and developing (trachoma and onchocerciasis) world, which cause millions to lose their sight. Neovascularization is divided into two main processes; Vasculogenesis and Angiogenesis. The former Vasculogenesis is the formation of new blood vessels from bone marrow derived angioblast, while the latter is formation of new blood vessels from already present vascular structures. Corneal NV may not only reduce visual acuity but also it results in the loss of the immune privilege of the cornea, thereby worsening the prognosis of subsequent penetrating keratoplasty (PK). Pre-existing corneal stromal blood vessels have been identified as strong risk factor for immune rejection after corneal transplantation. Although various compounds have been shown to inhibit corneal neovascularization in experimental and clinical situations including steroids, indomethacin, cyclosporine, methotrexate, low molecular weight heparin sulphate, rapamycin and thalidomide there is still no clear consensus about the best treatment of corneal neovascularization. Although steroids are the mainstay of treatment in corneal neovascularization, they are not always effective and without complications. SUMMARY: Briefly, a dramatic regression of corneal NV in all eyes was confirmed by slit-lamp biomicroscopy within just a week after injection and no relapse was seen within the follow-up period of 2–3 months. In this study they used 2.5 mg (0.1 ml) of bevacizumab solution for corneal NV in patients. The results suggested that this dosage may be enough for corneal NV and could be repeated if necessary. Although some portion of bevacizumab might have been passed into the systemic circulation via subconjunctival vessels, a sufficient amount seemed to be maintained to lessen the corneal NV7. Our study findings provide evidence that anti-VEFG therapy could potentially offer a safer and effective alternative to conventional therapies in treating corneal neovascularization without potential adverse effects. The initial impressive short term response and the high tolerance to subconjunctival bevacizumab therapy offer encouraging results for the potential role of subconjunctival anti-VEGF therapy in treating corneal diseases associated with corneal NV. CONCLUSION Subconjunctival injection of Bevacizumab can be used safely and effectively for corneal neovascularization resulting from different types of disorders. It may provide an additional strategy in improving success of corneal grafts in these patients. This is a short term study. However long-term follow-up is necessary to determine whether repeat injections are necessary.
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | subconjunctival injection; bevacizumab; corneal neovascularization |
| Subjects: | MEDICAL > Ophthalmology |
| Depositing User: | Devi S |
| Date Deposited: | 27 Jul 2017 07:41 |
| Last Modified: | 27 Jul 2017 07:44 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/2250 |
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