Experimental Study Of The Effect Of X-Ray Radiation On Astrocyte After Optic Nerve Injure Indirectly

Experimental study of the effect of X-Ray radiation onastrocyte after optic nerve injure indirectlyAbstractObjective:The purpose of the present study are as followings: ~D Most cases seen in clinics are indirect injuries. It is an urgent need to replicate the animal model for elucidation of the pathological course and for direction of clinical treatment of indirect optic nerve injuly. ㏕hrough copying the model of adult rabbit's optic nerve injury indirectly, we investigate the effect of X-Ray on reactive astrocyte.Method:?Under general anesthesia, the bilateral supra-orbital notches and orbital walls were surgically exposed. A rectangular gap on either side of orbital walls was made by excision of a portion of orbital lamina (8mm deep and 6 mm wide) from supra-orbital notch downward to the optic foranien, so the underlying optic nerve was left intact. Then a 2 m longs 25mm inner diameter self-made traumatic tube was perpendicularly placed 25 mm above the traumatic clamp. Lastly, a rustless steel ball, (weight 45 g; diameter 22.25mm) was dropped freely from the upper orifice of the traumatic tube and hit upon the upper surface of traumatic clamp. Occurrence of fixed pupil dilatation in company with loss of direct light reflex immediately after the struck was taken as criteria for a successful trauma. The optic nerve on the control side was not struck. ?1, 2, 3, 4week after injuring indirectly optic nerve, we gave irradiation dose of 35,45,55GY on experimentation group, observed all animal's general condition, size of pupil. 60 days after irradiation, optic nerve tissues were obtained for histology examination, quantitative analysis with image analyzer.Result:@the common state of experimental animals were all right, fixed pupil dilatation in company with loss of direct light reflex immediately after the struck was occurrence in 12 traumatic eyes. Coming round after anesthesia, pupil of 9 cases appear anomaly ellipse or pear shape. Pupil of 3 cases appear ellipse, average diameter was 9.3mm. On the control side, there were 4 cases to appear pupil out of the way, Pupil of 3 cases appears anomaly ellipse and Pupil of 1 cases shortens like needlepoint. Incidence of optic nerve injury was 100%, death 8.3% in 7 days, gross anatomy, brain contusion 33.3%, infection 8.3%, bone fractures 83.3%, hemorrhage of neurilemma91.7%, subneunlemma hematoma 75.0%, separation of optic nerve 25.0% and trauma in both optic nerve 33.3%. ﹖here have significant difference of reactive astrocyte number among experimentation groups. the astrocyte number抯 reduce degree is relate to irradiation dose and time. Irradiation in 2 weeks after trauma, there were significant decreases of astrocytes, however, irradiation preponderating over 2 weeks, there were not significant change in number of astrocytes. 2 weeks after injury and dose of 45GY, there were most significant decreases of Gila scar in radiated area.Conclusion:Opening strike is easy to use and of high success rate. Which can replicate animal model approaching clinical features of indirect optic nerve injury, X-Ray irradiation can restrain reactive astrocyte hyperplasia in adult rabbit optic nerve, which provided some experimental basis for optic nerve regeneration after injury.