【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。更多还原

【Abstract】 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 keratomileusis(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(D6.5 mm) zone was also calculated.The correction of myopic astigmatism were evaluated by LASIK based on standard vector analysis.Results The DAT of the 106 LASKI patients was(0.67±0.26)mm,D6.5mm was(57.65±19.63)μm and D3.0 mm was(16.37±4.59)μm.The D6.5 mm of low-midrange astigmatism group(48.43±16.57)μm was significantly lower than that of high astigmatism group(60.79±18.36)μm(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 positively correlated with D3.0 mm(r=0.46,P<0.01).The |EV|(absolute error vector) of low-midrange astigmatism group was significantly lower than that of high astigmatism group(P<0.05).The |EV| 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 unevenness of distribution of corneal thickness may influence the outcome of correction of myopia with high astigmatism by LASIK.更多还原