眶骨折后内壁下壁容积扩大与眼球内陷的关系

Relation between enlarged volume of medial wall and degree of enophthalmos after orbital fracture

目的通过对眶骨折后容积扩大量与眼球内陷值以及分别对眶内壁、眶下壁容积扩大量与眼球内陷值之间完成相关性研究，探讨对眼球内陷影响较大的变量，为临床诊断和治疗提供依据。方法对17例单侧眼眶骨折（内壁下壁联合骨折）继发晚期眼球内陷的患者行螺旋CT扫描（64排），层厚0．625mm，以Dicom格式存储并输入Mimics软件，对眶容积、眼球突出度、眶内壁容积扩大量、眶下壁容积扩大量分别进行测量。对眼眶容积和眼球内陷值进行直线相关与回归分析，对眶内壁扩大量、眶下壁扩大量和眼球内陷值进行多元线性相关与回归分析。结果眼眶容积扩大量（V）和眼球内陷值（E）之间的直线回归方程：E=0．851—0．197（Pearson法，r=0．969，P〈0．01，回归系数95％的可信区间0．732~0．970）；眼球内陷值（E）与眶内壁容积扩大值（VM）、眶下壁容积扩大值（VF）之间的标准化多元回归方程：E=0．690VF＋0．413VM-0．086（Setpwise法，入选为0．5，剔除为0．1，P％0．01）；比较自变量的标准化回归系数，bF（0．690）〉bM（0．413）。结论眼眶骨折后眶容扩大量和眼球内陷值呈高度正相关，眼眶容积每扩大1ml，眼球内陷约0．8mm；眶下壁骨折容积扩大量对眼球内陷值的影响比眶内壁骨折容积扩大量大，前者是后者的1．56倍。

Objective To explore the relation between the enlargement of orbital volume and the degree of enophthalmos, and that between the enlarged volume of floor together with that of medial wall and the degree of enophthalmos. Methods A total of 17 patients of unilarteral orbital fracture were scanned by MSCT （slice width 0. 625mm）, who suffered late enophthalmos as a results of combination fracture of the medial wall and floor. The clinical data were collected, and input into a software named MIMICS in order to measure orbital volume, the degree of enophthalmos, the enlarged volume of medial wall, and that of orbital floor. Simple linear correlation and regression were carried out between the en- largement of orbital volume and the degree of enophthalmos. Mutiple linear correlation and regression were carried out between the enlarging volume of floor together with that of medial wall and the degree of enophthalmos. Results The equation of the enlargement of orbital volume （V） and the degree of enophthalmos （E） was E= 0. 851V--0. 197 （Pearson r=0. 969, P〈0.01, the 95 0% confidence intervals of 0. 732--0. 970）. The standardized equation between the enlarged volume of floor together with that of medial wall and the degree of enophthalmos was E= 0. 690 VF＋ 0.413 VM-- 0. 086 （ setpwise, entry = 0.5, removal= 0.1, P〈0.01） ; Comparing the standardized coefficients of independent variables, the out- come was bF （0. 690） 〉 bM（0. 413） . Conclusion Significant linear correlation between the increment of the orbital volume and the degree of enophthalmos is found that 1.0 ml enlargeement in bony volume causes approximately 0.9 mm of enophthalmos; enlarged volume of floor has more powerful influence on the degree of enophthalmos than enlarged volume of medial wall, the former is 1.56 times of the latter.