Clinical Observation Of Beta Irradiation On Corneal Neovascularization

Corneal neovascularization was due to trauma, chemical burns, immune and inflammatory response, infection and lack of oxygen and so on, undermining the balance of promoting angiogenesis factor and inhibiting angiogenesis factor, capillaries grew into peripheral corneal 1-2mm, also known as the CNV. Despite the CNV has cleared infection, promote wound healing and prevent corneal stroma dissolved advantage, but can reshape the cornea of the micro-environment in which the anterior segment of the associated immune deviation pardon disappeared, is the high risk factor of corneal transplant rejection. Its structure and function is not perfect, and plasma leakage can occur easyly, cause corneal edema, fibrosis and sustained inflammation then influence visual capacity, serious blinding. Therefore the treatment of corneal neovascularization is of great significance for reduce corneal edema and turbidity, improve the transparency of the cornea and increase transplant achievement ratio in such corneal diseases. At present, foreign scholars have suggested various ways to inhibit the formation of CNV and promote regression of neovascularization. Such as: glucocorticoids, immunosuppressants, antimetabolite and various neovascularization associated cytokines antibody drug treatment; Laser, Photodynamic therapy and ocular surface reconstruction surgery. However, a variety of treatment methods are there so many flaws. The search for a safe and effective, economic and facility, easy to engage in clinical extensively treatment is the urgent issue what us ophthalmic workers are facing. Based on the application of beta radiation treatment of experimental corneal neovascularization achieved positive effect, for the clinical observation ofexploratory beta irradiation on CNV. 8 eyes of 8 peoples are selected in patients with CNV to the third affiliated hospital of Jilin university for treatment, to give beta irradiation one time per day, 7-10 day course of treatment, efficacy little can be duplication of treatment, the total dose not more than 16Gy. Through the slit lamp microscope record CNV changes, eye complications and photographed. Based on corneal neovascularization area (A) formula A area (mm2) = C/12 x 3.1416[r2-(r-l) 2] compared neovascularization area before and after the irradiation to evaluate the efficacy, C to represent the bell points that neovascularization involving corneal circumference, r to represent corneal radius =5.5mm, l to represent the length of the longest corneal neovascularization branch penetrated the cornea by corneal limbal. All the patients with congestive level were significantly reduced, 6 eyes corneal neovascularization area (A) were reduced by more than 50% compared with before. Two eyes which have adopt lamellar keratoplasty, after the first beta irradiation, CNV area was respectively reduced 12.47% and 14.85% than before, after repeated treatment was respectively decreased 24.78% and 26.74%; One eye which has adopt amniotic membrane transplantation, after the first treatment neovascularization area was decreased 32%, after repeated treatment was decrease 68%. Congestive level was significantly reduced. It is suggest that beta irradiation on CNV is an effective treatment, for the CNV that located in deep stromal layer, has rich transport support, intensive vascular, appropriate radiation dose increased access to good effect. The effective range of 90/Sr-90/Y ray emission in the water and the tissue is about 2mm, but 80% of the energy in the tissues of 2mm be absorbed. It has been reported that to utilize dose of 35Gy irradiation for the prevention of eye pterygium recurrence noserious complications. The complication such as corneal edema, peripheral neovascularization bleeding was occured during the treatment in the case. But self-absorbed and dissipated in the period of follow-up. And there is not lens injury, uveitis response, and other complications. The Application for ophthalmic 90/Sr-90/Y is compact, and easy to carry. Application beta irradiation is expected to become a safe,effective and economic facilities, easy to extensively promote way.