角膜顶点和最薄点矢量距离与角膜厚度非均匀性分布的关系及其对LASIK矫正散光的影响  

Relationship between vector distance from corneal apex and thinnest point and unevenness distribution of corneal thickness and the influence on correction of astigmatism by LASIK

作　　者：王树林[1] 史伟云[2,3] 刘明娜[2,3] 王海莹[2,3] 李静[2,3] 

机构地区：[1]郑州人民医院眼科,河南省郑州市450003 [2]山东省医学科学院 山东省眼科研究所 [3]山东省眼科医院,山东省济南市250021

出　　处：《眼科新进展》2013年第8期736-739,共4页Recent Advances in Ophthalmology

基　　金：国家自然科学基金资助(编号:11204277)~~

摘　　要：目的采用Pentacam观察并计算角膜顶点和最薄点之间的矢量距离(vector distance from corneal apex to thinnest point,DAT)与角膜厚度非均匀性分布的关系,并探讨其对准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)矫正散光效果的影响。方法选取行LASIK矫正近视合并散光且术后3个月随访资料完整的106眼,分为中低度散光组(-0.25～-2.00D)和高度散光组(-2.25～-4.00D)。根据Pentacam的检测结果计算DAT,并以角膜最薄点为圆心,计算直径为3.0mm(D3.0mm)和6.5mm(D6.5mm)的同心圆与角膜厚度变化最大和最小子午线交点处厚度的差值。利用标准矢量分析法评估LASIK术后3个月时散光的矫正效果。结果 106眼LASIK患者的DAT为(0.67±0.26)mm,D6.5mm为(57.65±19.63)μm,D3.0mm为(16.37±4.59)μm,中低度散光组的D6.5mm为(48.43±16.57)μm,小于高度散光组的(60.79±18.36)μm,差异有统计学意义(P<0.05)。106眼的DAT分别与D6.5mm、D3.0mm呈正相关(r=0.48、0.51,均为P<0.01),D6.5mm和D3.0mm呈正相关(r=0.46,P<0.01)。术后3个月中低度散光组的|矢量误差|(矢量误差的绝对值)小于高度散光组,差异有统计学意义(P<0.05)。高度散光组的|矢量误差|与D6.5mm呈正相关(r=0.52,P<0.05)。结论角膜顶点和最薄点之间的矢量距离可能与角膜厚度的非均匀性分布有关,角膜厚度的非均匀性分布会影响LASIK对高度散光的矫正效果。Objective To observe the relationship between the vector distance from corneal apex and thinnest point （DAT） and unevenness of distribution of corneal thickness by Pentacam, and investigate the influence on the correction of astigmatism by laser in situ keratomilensis （LASIK）. Methods The data of 106 myopic astigmatism eyes, treated with LASIK and followed up for 3 months, were collected, and then they were divided into two groups, low-midrange astigmatism group （ -0.25 ~ -2.00 D）and high astigmatism group （ - 2.25 - 4.00 D）. DAT was calculated by Pentacam, corneal thinnest point was centered, and the unevenness of distribution of corneal thickness of 3.0 mm（D3.0 mm） and 6.5 mm（DS. 5 mm） zone was also calculated. The correction of myopic astigmatism were evaluated by LASIK based on standard vector analysis. Re- i sult The DAT of the 106 LASKI patients was（0.67 ± 0.26） mm, DS. 5mm was（57.55 ± 19.63 ）μm and D3.0 mm was （ 16.37 ± 4.59） pan. The 136.5 mm of low-midrange astigma- tism group（48.43± 16.57 ） μm was significantly lower than that of high astigmatism group （60.79 ± 18.36） pma（P 〈0.05）. In 106 eyes,the DAT was positively correlated with D6.5 mm and D3.0 mm（r =0.48,0.51 respectively,both P 〈0.01 ）. The D6.5 mm was posi- tively correlated with D3.0 mm（ r = 0.46 ,P 〈 0.01 ）. The I EVI （ absolute error vector） of low-midrange astigmatism group was significantly lower than that of high astigmatism , group （P 〈 0.05 ）. The I EV I of high astigmatism group was positively correlated with D6.5 mm（ r = 0.52, P 〈 0.05 ）. Conclusion The vector distance from corneal apex and thinnest point may be correlated with the unevenness of distribution of corneal thickness. The unevelmess of distribution of corneal thickness may influence the out-come of correction of myopia with high astigmatism by LASIK.

关 键 词：角膜顶点 厚度 矢量分析 散光 准分子激光 

分 类 号：R779.6[医药卫生—眼科]