摘要
目的研究老年性白内障患者模拟角膜曲率计散光和总角膜散光大小及轴位的差异,评价角膜后表面散光对总角膜散光的影响。方法 80例老年性白内障患者(105眼,左47眼,右58眼)手术前行Pentacam检查,记录角膜前后表面散光,并对角膜前后表面散光行相关性分析。模拟角膜曲率计散光用屈光指数1.337 5及角膜前表面曲率半径计算,总角膜散光由前→后表面散光在角膜后表面的矢量合计,计算模拟角膜曲率计散光和总角膜散光的矢量差E、大小差E和轴位差A。结果角膜前表面散光和后表面散光大小间无明显相关性(P=0.98),后表面散光对前表面散光的平均补偿作用为5.79%。总角膜散光及模拟角膜曲率计散光大小分别为(1.12±0.65)D和(1.07±0.64)D,差异具有统计学意义(t=-2.40,P=0.02);两者轴位分别为(67.93±56.50)°和(68.90±59.68)°,差异无统计学意义(t=-0.27,P=0.79)。散光值大小及轴位差异的算术均值分别是(0.05±0.23)D和(-0.57±13.02)°,绝对值是(0.19±0.15)D和(7.00±10.97)°。两者散光大小差别大于0.50 D或轴位差别大于10°的有30眼,占28.57%。结论老年性白内障患者忽略角膜后表面测量可能会导致具有临床意义的角膜散光值估计的差异。
Objective To evaluate the effects of posterior astigmatism（ PA） on total corneal astigmatism by the difference of magnitude and axis between simulated keratometry astigmatism and total corneal astigmatism in age-related cataract. Methods A rotating Scheimpflug camer a（ Pentacam Oculus,Wetzlar,Germany） was used to measure 105 eyes of 80 patients for cataract surgery. Both anterior stigmatism（ AA） and PA were recorded. The simulated keratometry astigmatism（ KA） was calculated by the anterior corneal surface measurement and the index of 1.3375,while the total corneal astigmatism（ TA） was derived by doubled-angle vector analysis of the astigmatisms on both corneal surfaces. Then,the differences of vector,magnitude,axis were calculated between KA and TA. Results AA and PA had no obvious relationship（ P〉 0. 98）,the compensation effects of PA on AA was 5. 79%. The magnitude of KA and TA were（ 1. 12 ±0. 65） D and（ 1. 07 ± 0. 64） D,respectively,and there was significant difference（ t =- 2. 40,P= 0. 02）. The axis of KA and TA were（ 67. 93 ± 56. 50） ° and（ 68. 90 ± 59. 68） °,respectively,there was no significant difference（ t =- 0. 27,P = 0. 79）. The mean arithmetic and absolute error of KA for TA magnitude were（ 0. 05 ± 0. 23） D and（ 0. 19 ± 0. 15） °,respectively. The mean arithmetic and absolute error of KA for TA axis were（- 0. 57 ± 13. 02） D and（ 7. 00 ± 10.97） °,respectively. In the whole study,30 eyes（ 28. 57%） had either a magnitude difference more than 0. 50 D or an axis difference more than 10° between KA and TA. Conclusion Omission of PA may lead to clinical significant inaccuracies in estimating of the corneal astigmatism in age-related cataract patients.
出处
《眼科新进展》
CAS
北大核心
2015年第7期652-655,共4页
Recent Advances in Ophthalmology
关键词
角膜后表面散光
总角膜散光
模拟角膜曲率计散光
老年性白内障
posterior corneal astigmatism
total corneal astigmatism
simulated keratometry astigmatism
age-related cataract
