穿透角膜移植术各屈光变量及其相互关系

Relationships among different refractive components following penetrating keratoplasty

目的研究穿透性角膜移植(penertrating keratoplasty,PKP)术后各屈光变量间的数量关系,探讨PKP引起眼球屈光状态变化的规律。方法32只新西兰大白兔随机分为A、B、C、D四组分别行PKP术,植孔大小均为7 mm,植片直径依次为7、7.25、7.5和8.0 mm,将屈光变量植片差值、角膜屈折力、角膜厚度、前房深度、晶状体厚度依次设为自变量X1、X2、X3、X4、X5,眼轴长度为应变量Y,分别在术前、术后1周、2周、1月、2月、3月进行观察测量并建立Y与各自变量间的数学模型。结果术前各屈光变量在各组间无显著差异(P>0.05)。综合各时间点的参数获得了屈光变量间的回归方程,如:术后3月Y=15.238+0.199X1+0.544X2-0.060X3+0.129X4-0.094X5。结论PKP术中应用不同植片/植孔大小差值可以引起眼球屈光状态的改变。所建立的回归方程数学模型对PKP术后屈光状态的控制具有一定指导作用。

Objective To explore the relationships among different refractive components following penetrating keratoplasty（PKP） and to evaluate the refractive changes induced by PKP. Methods 32 New Zealand white rabbits were divided into groups A, B, C and D. The diameter of the adopt hole was 7.0 nun in each group, but the donor diameter was 7.0 nun, 7.25 mm, 7.5 nun and 8.0 mm in groups A, B, C and D. The differences of donor button and host bed（△d）, comeal dioptric power, comeal thickness, anterior chamber depth and lense thickness were supposed as cause quantity X1 , X2, X3 , X4 and X5, and the axial length served as the result quantity. All the refractive components were examined before the operations and 1 week, 2 weeks, 1 month, 2 months and 3 months after the operations. Mathematic models of regression equations were built. Results Before the operations, no statistical differences of the refractive components were found in the four groups. After the operations, the math- ematic models of regression equations were built as follows： 3 month after the operations： Y= 15.238 ＋ 0. 199X1 ＋ 0.544X2 - 0.060X3 ＋ 0. 129X4 - 0.094X5. Conclusion Different sizes of donor button and host bed （△d） can induce changes of refractive components during PKP. The established mathematic model of regression equations is helpful in quantifying the refractive error and controlling the refraction of PKP.