聚焦超声辐照兔眼角膜的生物效应研究

Biological effects of focused ultrasound on rabbit's cornea

目的:利用聚焦超声(focused ultrasound,FU)热效应对兔眼角膜进行辐照,观察其生物效应的变化。方法:13只新西兰兔(26眼)根据辐照功率及辐照角膜直径的不同随机分为A、B、C组。设计A组辐照功率为1 W,辐照角膜直径为9 mm;B组辐照功率为1.5 W,辐照角膜直径为9 mm;C组辐照功率为1 W,辐照角膜直径为7 mm。分别于术前及术后3、10 d、1月、2、3月对术眼进行裂隙灯、自动验光仪、角膜地形图、内皮细胞计数仪及非接触眼压的检查及记录。结果:术后即刻24眼(92.3%)角膜辐照区上皮缺损,术后3 d 26眼(100%)角膜上皮完整。角膜中央曲率于术后1月开始降低,随观察时间延长呈逐渐降低趋势;屈光度术后呈正向增加趋势,向远视方向发展,与角膜中央曲率变化趋势一致。非接触眼压术后3、10 d降低,术后1、2、3月恢复到术前水平。角膜内皮细胞计数术前术后无明显变化。结论:辐照兔眼周边角膜引起角膜中央曲率降低。FU应用于兔眼角膜安全性较高。

Objective：To study the biological effects of focused ultrasound（FU）on rabbit’s cornea. Methods：Totally 26 eyes of 13 New Zealand rabbits were randomly divided into A,B,C groups according to FU power and corneal diameter. Group A was irradiated using power of 1 W and corneal diameter of 9 mm;group B was irradiated using power of 1.5 W and corneal diameter of 9 mm;group C was irradiated using power of 1 W and corneal diameter of 7 mm. Rabbits were examined with slit-lamp microscope,auto refractometer,corneal topography,specular microscopy and non-contact tonometer before the operation and on 3,10 d and at 1,2,3 months after the operation respectively. Results：Twenty-four eyes（92.3%）had corneal epithelium defect in irradiated area immediately after the operation and all 26 eyes（100%）got complete corneal epithelium on 3 d after the operation. Curvature of the central corneal was reduced gradually 1,2,3 months postoperatively（P＆lt;0.05）;diopter was increased gradually（P＆lt;0.05）,presenting a trend to hyperopia,the same as the change of central corneal curvature. Non-contact intraocular pressure was reduced on 3,10 d postoperatively（P＆lt;0.05）and was recovered at 1,2,3 months postoperatively. Corneal endothelial cell density was not statistically significant between preoperative and postoperative observation. Conclusions：FU irradiation at the peripheral cornea of rabbits can reduce central corneal curvature and is safe when applied in rabbit’s cornea.