目的 探讨A超和IOL Master测量人工晶状体度数的精确性,为白内障手术提供客观的临床数据。方法 选取300例300眼老年性白内障患者,术前采用A 超和IOL Master测量眼轴长度、自动验光仪测量角膜曲率,A超组利用自动验光仪的角膜曲率数据,IOL Master组利用仪器自带的角膜曲率数据,均使用SRK-T公式计算需要植入的人工晶状体度数,观察术后3 m的屈光状态,使用自动验光仪检测患者屈光状态并分析。结果 所有被列入研究的患眼随机分为A超组和IOL Master组, A超组测得的平均眼轴长度为(23.21±0.59)mm,IOL Master组测得的眼轴长度为(23.22±0.59)mm,两组数据对比差异无统计学意义(P>0.05);利用自动验光仪测量的术前平均角膜曲率为(44.01±1.79)D,利用IOL Master测量的术前平均角膜曲率为(44.13±1.62)D,两者比较差异无统计学意义(P＞0.05);A超组和IOL Master组术后的平均绝对屈光误差(mean absolute refractive error,MAE)分别为(0.43±0.26)D、(0.42±0.17)D,两组比较差异无统计学意义(P>0.05)。结论 IOL Master在操作上略优于A超,但在人工晶体度数测量上与A超比较没有发现明显优势,不能完全取代A超,两者结合更能确保人工晶体度数测量的精确性。

Objective By discussing the accuracy of A-scan and IOL Master in intraocular lens power measurement, to offer Objective clinical data for cataract surgery.Methods Three hundred patients(300 eyes)with age-related cataract were included in the study. Before surgery,axial length was measured by A-scan and IOL Master respectively and corneal curvature was measured by auto refractometer. A-scan group used the corneal curvature data of the auto refractometer. IOL Master group used the corneal curvature data from the instrument. Intraocular lens power was calculated according to the SRK-T formula.We observed the refractive state of 3m after operation, detected and analyzed the patient's refractive data by the auto refractometer.Results All patients who were included in the study were randomly divided into A-scan group and IOL Master group.The mean axial length was (23.21±0.59) mm measured by A-scan, the mean axial length was (23.22±0.59) mm measured by IOL Master. There was no significant difference between them (P>0.05). The preoperative mean corneal curvature measured by the auto refractometer was (44.01±1.79)D. The preoperative mean corneal curvature measured by IOL Master was (44.13±1.62)D. There was no statistically significant difference between them (P＞0.05). The mean absolute refractive error ( MAE) in A－scan group was (0.43±0.26)D and in IOL Master group was (0.42±0.17)D. There was no statistically significant difference between them (P＞0. 05).Conclusion IOL Master group operated slightly better than A-scan group, but we did not find a significant advantage in intraocular lens power measurement with A-scan group. IOL Master may not completely replace A-scan. The combination of the two ensures the accuracy of the measurement in intraocular lens power.

目的 探讨Sirius与A超对不同程度近视患者中央角膜厚度(CCT)的测量差异。方法 对225例(450眼)拟行角膜屈光手术的近视患者,按低、中、高度近视分三组,依次用Sirius和A超测量CCT。 测量结果行配对t检验、 Pearson相关及 Bland-Altman分析。结果 低、中、高度近视组中,Sirius所测CCT均数分别为(542.61±29.19)μm、(543.96±27.02)μm、(547.25±22.53)μm;A超CCT均数分别为(538.51±29.12)μm、(540.98±26.56)μm、(542.19±21.64)μm。不同近视组中,Sirius测量值均略大于A超值,且两者高度正相关,差异有统计学意义(P<0.05)。Bland-Altman分析,不同近视组中,两种仪器测量CCT的一致性较好。结论 Sirius在绝大多数情况下能够替代传统的A超角膜测厚仪,但对拟行激光手术的高度近视患者应该综合考虑两种仪器测量结果。

Objective To study the measurement differences of central corneal thickness(CCT) in different degree of myopia by Sirius and ultrasound pachymetry(UP). Methods 225 myopic subjects(450 eyes)were recruited and divided into three groups according to the degree of refractive errors. The CCT were obtained from the eyes for each subjects using the Sirius and UP. Data were compared by using paired t-tests and the Pearson correlations. Bland- Altman analysis of all pairs were determined. Results The mean CCT in low myopic group obtained from Sirius and UP were (542.61±29.19)μm and(538.51±29.12)μm,respectively. The mean CCT in medium myopic group by Sirius and UP were(543.96±27.02)μm and(540.98±26.56)μm.The measured mean CCT in high myopic group were(547.25±22.53)μm and(542.19±21.64)μm by Sirius and UP. The mean CCT measurements between the two instruments were high correlated and statistically different(P<0.05) in the three groups respectively. In different myopia groups Sirius has good coincidence with UP in measuring CCT according to the Bland-Altman plot. Conclusion In vast majority of cases,Sirius can replace traditional UP in measuring CCT. But for the preopreative examination of the high myopia patients, we need to think twice about the difference between the two measurements.