Avetisov S E, Fedorov A A, Vvedenskiĭ A S, Neniukov A K
Oftalmol Zh. 1990(1):54-8.
Investigations were carried out in 4 rabbits. The right eyes of the animals were experimental, the left eyes--tentative (radial keratotomy with 8 incisions, maximum depth of the central zone--3.0 mm in diameter). Mechanical trial of isolated corneas with a scleral rim were made 6 months after surgery by means of a trial machine "Instron-1122" and a special clamping device. After trial, the specimens were investigated by a method of scanning electron microscopy. As a result of mechanical action, the rupture of the cornea in the zone of contact with the punch was recorded in all cases. In the control eyes, the area of the cornea was practically the same as the zone of the punch pressure on the cornea. In tentative eyes, the rupture was connected with keratotomy scars in all cases. The values of destructive load, transference of the punch at the moment pattern destruction and destructive tension along the punch contour were determined. The results obtained have shown that anterior radial and not crossing the limbus incisions in the cornea produce changes in mechanical characteristics of the cornea: in the sites of keratotomy scars, "conditionally" weak places of the corneoscleral coat are formed, the probability of breaks and tears of which in contusions of the increases.
对4只兔子进行了研究。动物的右眼为实验组，左眼为对照组（8条切口的放射状角膜切开术，中央区最大深度——直径3.0毫米）。术后6个月，借助“Instron - 1122”试验机和特殊夹持装置对带有巩膜缘的离体角膜进行力学试验。试验后，通过扫描电子显微镜方法对标本进行研究。在所有情况下，由于机械作用，均记录到角膜在与冲头接触区域发生破裂。在对照眼中，角膜面积实际上与冲头对角膜的施压区域相同。在试验眼中，所有情况下破裂均与角膜切开术瘢痕有关。测定了破坏载荷、冲头在图案破坏瞬间的位移以及沿冲头轮廓的破坏张力值。所得结果表明，角膜前部放射状且不穿过角膜缘的切口会导致角膜力学特性发生变化：在角膜切开术瘢痕部位形成了角膜巩膜层的“条件性”薄弱部位，在挫伤时其破裂和撕裂的可能性增加。
