背景：目前已有研究报道了一种MATLAB的定制算法，用于Triton光学相干断层扫描血管成像(optical coherence tomography angiography，OCTA)图像的中心凹无血管区(fovea avascular zone，FAZ)的自动测量。由于这种算法非开源，且难以获取，因而大大限制了其在临床实践和科学研究中的应用。本研究提出一种用于Triton OCTA图像的FAZ自动分割的开源算法，即Smooth Level Sets macro(SLSM)算法，并将其测量结果与MATL AB和人工方法相比较，评估该算法分割的准确性和可靠性。方法：纳入35位健康受试者的35只健眼，选用Triton OCTA机器中的3 mm×3 mm扫描模式，对其黄斑区进行连续4次扫描。分别用人工和自动方法(包括MATL AB和SLSM)，测量浅层毛细血管图像中FAZ的面积、周长和圆度。分析各种自动算法的准确性、重复性，以及与人工方法结果的一致性。结果：SLSM算法的准确性仅低于人工方法，而高于MATLAB算法(Dice系数：人工方法，0.9568；SLSM，0.9506；MATL AB，0.9483)。SLSM和MATL AB测量FAZ面积的重复性均很高[组内相关系数(intraclass correlation coefficient，ICC)：SLSM，0.987；MATLAB，0.983]。SLSM、MATLAB测量FAZ面积的结果均与人工方法呈很高的一致性(ICC：SLSM，0.973；MATL AB，0.968)。结论：SLSM在Triton OCTA图像的FAZ自动分割中的准确性高于MATL AB，其测量结果与人工测量结果很相近。作为免费和开源的资源，SLSM有望成为Triton OCTA图像中有效可靠的FAZ自动分割和测量方法。
Background: Previous studies have proposed an automated customized program named MATLAB used in the foveal avascular zone (FAZ) measurements in Triton optical coherence tomography angiography (OCTA) images. But it is not open-source and not easy to obtain, which will largely restrict its application in clinical practice and medical research. In this study, we aimed to investigate the feasibility of the Smooth Level Sets macro (SLSM), a free and open-source program, and compared with the manual measurements and MATLAB in the FAZ quantification in Triton OCTA. Methods: Thirty-five eyes of 35 healthy subjects were scanned four times continuously using Triton OCTA. Manual and automated methods including the SLSM and MATLAB were used in the FAZ metrics (area, perimeter, and circularity) of the superficial capillary plexus. The accuracy, repeatability of all methods, and agreement between automated and manual methods were analyzed. Results: The SLSM presented higher accuracy with a higher average Dice coefficient (0.9506) than MATLAB (0.9483), which was just second to the manual method (0.9568). Both the SLSM [intraclass correlation coefficient (ICC) =0.987; coefficient of variation (CoV) =3.935%] and MATLAB (ICC =0.983; CoV =4.165%) showed excellent repeatability for the FAZ area. They also had excellent agreement with manual measurement (SLSM, ICC =0.973; MATLAB, ICC =0.968). Conclusion: The SLSM exhibits better accuracy than MATLAB in the automated FAZ measurement in Triton OCTA, the results of which were comparable to those obtained by manual measurement. This free and open-source program may be an accessible and feasible option for automated FAZ segmentation on Triton OCTA images.
目的：在硅油取出联合白内障手术患者中，使用扫频源光学相干断层扫描生物测量仪OA-2000进行生物测量，比较10种人工晶状体(IOL)屈光力计算公式的准确性。方法：回顾性分析2021年3月—7月于中山大学中山眼科中心接受硅油取出联合白内障手术的患者共62例(62眼)，所有患者均使用扫频源光学相干断层扫描生物测量仪OA-2000进行生物学参数测量。计算并比较新公式[Barrett Universal II (BUII)、Emmetropia Verifying Optical(EVO) 2.0、Hill-Radial Basis Function (Hill-RBF) 3.0、Hoffer QST、Kane、Pearl-DGS]及传统公式(Haigis、Hoffer Q、Holladay 1、SRK/T)的预测准确性，主要评价指标为绝对预测误差中位数(MedAE)及平均绝对预测误差(MAE)。按眼轴长度≤23 mm(组1)，>23 mm且≤26 mm(组2)与>26 mm(组3)进行亚组分析。结果：6个新公式、Haigis、SRK/T公式均出现近视漂移(-0.47 ~-0.27 D，P<0.05)，而HofferQ及Holladay 1公式无系统误差(P>0.05)。Kane公式的MedAE(0.55 D)及MAE(0.81 D)最小，但公式间比较差异无统计学意义(P>0.05)。组1中所有公式均出现近视漂移(-1.46~ -1.25 D，P<0.05)，而其他亚组比较差异无统计学意义(-0.32 ~ 0.41 D，P>0.05)。在组1中，Pearl-DGS公式的MedAE(0.97 D)及MAE(1.26 D)最小，且优于Hill-RBF 3.0(P=0.01)及SRK/T公式(P=0.02)；组2中，Kane公式具有最小的MedAE(0.44 D)及MAE(0.66 D)；组3各个公式屈光预测准确性比较差异无统计学意义(P>0.05)。结论：在使用OA-2000进行术前生物测量时，Kane公式在接受硅油取出联合白内障手术患者中的预测准确性较高；而眼轴长度≤23 mm时，Pearl-DGS公式可能更为准确。
Objective: To compare the accuracy of 10 intraocular lens (IOL) power calculation formulas in patients undergoing combined silicone oil removal and cataract surgery, biometry is performed using the swept-source optical coherence tomography biometer OA-2000. Methods: A retrospective analysis. A total of 62 patients (62 eyes) who underwent combined silicone oil removal and cataract surgery in Zhongshan Ophthalmic Center, Sun Yat-sen University from March to July in 2021 were enrolled. Preoperative biometry was performed by OA-2000 in all patients. New-generation formulas (Barrett Universal II [BUII], Emmetropia Verifying Optical [EVO] 2.0, Hill-Radial Basis Function [Hill-RBF] 3.0, Hoffer QST, Kane and Pearl-DGS) and traditional formulas (Haigis, Hoffer Q, Holladay 1 and SRK/T) were evaluated. The median absolute prediction error (MedAE) and mean absolute prediction error (MAE) were the main parameters used to assess accuracy. Subgroup analyses were performed based on the axial length of 23 mm and 26 mm. Results: Six new-generation formulas, Haigis, and SRK/T showed myopic shift (-0.47 ~ -0.27 D, P<0.05), while no systematic bias was found in Hoffer Q and Holladay 1 displayed (P>0.05). The smallest MedAE (0.55 D) and MAE (0.81 D) were found in Kane formula, but there was no statistically significant difference compared with other formulas (P>0.05). The myopic shift (-1.46 ~ -1.25 D, P<0.05) in eyes shorter than 23 mm were found in all formulas, while there was no significant systematic bias (-0.32 ~ 0.41 D, P>0.05) in other subgroups. In axial length shorter than 23 mm, the Pearl-DGS formula stated the smallest MedAE (0.97 D) and MAE (1.26 D), and was significantly more accurate than Hill-RBF 3.0 (P=0.01) and SRK/T (P=0.02). In eyes with an axial length between 23 mm and 26 mm, the Kane formula had the lowest MedAE (0.44 D) and MAE (0.66 D). No significant difference was found in eyes longer than 26 mm. Conclusion: The Kane formula showed the highest accuracy in patients undergoing combined silicone oil removal and cataract surgery measured by OA-2000, whereas the Pearl-DGS formula could be more accurate in eyes with an axial length shorter than 23 mm.
目的：比较Pentacam三维眼前节分析仪与iTrace视觉分析仪在暗室环境中检测近视眼Kappa角的一致性。方法：采用回顾性研究，对近视门诊的86例志愿者共172眼使用iTrace视觉分析仪和Pentacam三维眼前节分析仪，分别测量其Kappa角，收集所测数据采用SPSS软件进行一致性分析。结果：Pentacam三维眼前节分析仪与iTrace视觉分析仪的Kappa角测量结果中，横坐标X值、纵坐标Y值和方位角度值比较差异有统计学意义(P<0.05)；弦距离值比较差异无统计学意义(P>0.05)。结论：Pentacam三维眼前节分析仪与iTrace视觉分析仪在近视患者Kappa角测量结果一致性存在差异，临床上应谨慎替换使用。
Objective: To compare the consistency of Pentacamand iTrace in detecting anglekappa. Methods: A retrospective study was carried out on a total of 172 eyes of 86 volunteers to measure the anglekappa by iTrace visual analyzer and Pentacamanterior section analyzer in Zhengzhou Aier Eye Hospital. The measured data were collected and analyzed by SPSS software. Results: In the measurement results between Pentacam and iTrace , there was a statistically significant difference in the X value, Y value, and azimuth angle values of the horizontal axis (P<0.05); There was no statistically significant difference in chord distance values (P>0.05). Conclusions: 3-D anterior section analyzer the significant difference is found in the concordance of the anglekappa measurement results between the Pentacam and iTrace. It should be caution to replace two kinds of equipment in clinical practice.
近视防控已经上升到我国国家战略层面，高度近视引起的视神经病变会损害视功能，但在临床上常常被忽视。OCT可以非侵入、高分辨率、快速以及可重复地定量视网膜各层厚度，是评估高度近视相关视神经病变的有力工具。由于高度近视常合并视盘和盘周的改变，视神经纤维层厚度的定量常出现误差。近年来，学者开始聚焦于黄斑区神经节细胞复合体(ganglion cell complex,GCC)厚度的研究，但其在高度近视眼中的变化规律尚不统一。该文针对近年来高度近视眼黄斑区GCC的测量规范、诊断价值、变化规律等进行综述，以期提高眼科医师对高度近视视神经病变的重视和研究水平。
Myopia prevention and control has risen to the national strategic level in China. Optic neuropathy caused by high myopia can damage visual function, but it is often ignored in clinical practice Optical coherence tomography (OCT) characterized by non-invasiveness, high resolution, rapid, and repeatable quantifying the thickness of each layer in the retina has emerged as a powerful tool for evaluating high myopia related optic neuropathy. Due to the changes in and near the optic disc in high myopia, errors often occur in the quantification of the thickness of the optic nerve fiber layer. In recent years, researchers have gradually focused on the study of the thickness of ganglion cell complex (GCC), but the regularity of its changes in high myopia is not yet unified. This article reviews the measurement specifications, diagnostic values, and change rules of GCC in the macular region of high myopia in recent years, in order to improve the attention and research level of ophthalmologists on high myopia optic neuropathy.
调节是人眼非常重要的功能，通过调节能随时改变人眼屈光系统的光学参数，与眼屈光不正及老视都有着密切的关系。测量眼调节力的常用方法分为主观测量法和客观测量法。主观测量法以移近移远法、负镜片法为代表。客观测量法以动态视网膜检影法和自动屈光仪法为代表。本文就调节力测量方法、测量准确度和调节力的最新研究进展进行综述，为眼科临床研究和应用提供选择依据。
Accommodation is an important function of the human eye, which can change the parameters of ocular refractive system and also has a strong correlation with the development of myopia and presbyopia. Several subjective measurements have been applied in accommodation assessment such as push-up test, push-down test and minus-lens procedures. It can be measured objectively by measuring the change in refraction of the eye with dynamic retinoscopy or autorefractor. This article reviews the application of measurement of accommodative amplitude and research progress in accommodation, providing clinical information for further studies．
目的: 探讨泪膜改变对 Goldmann 压平眼压计测量值的影响。方法: 将 68 例(136 只眼) 受检者随机分为 2 组, 每组 34 例。随机选择一只眼作为实验眼, 另一只眼作为对照眼。A 组的实验眼采用右旋糖苷 70 滴眼液滴眼, B 组的实验眼采用粘弹剂 Viscoat 滴眼。采用 Goldmann 眼压计测量 2 次眼压, 比较滴眼前、后测量值的差异。结果: A 组对照眼第 1、2 次的眼压测量值分别为(14.44±2.68) mmHg(1 mmHg = 0.133 KPa) 、(14.47 ± 2.69) mmHg, 两次眼压测量值的差异无统计学意义(t = - 0.329, P = 0.744) 。实验眼滴右旋糖苷 70 滴眼液前、后的眼压测量值分别为(14.41 ±2 .63) mmHg、(12.94 ± 2.59) mmHg, 两次眼压测量值的差异有统计学意义 (t = 13.949, P = 0.000) 。B 组对照眼第 1、2 次的眼压测量值分别为(14.29 ± 2.96) mmHg、(14.35 ± 3.12) mmHg, 两次眼压测量值的差异无统计学意义(t = - 0.466, P = 0.644) 。实验眼滴 Viscoat 前、后的眼压测量值分别为 (14.53 ± 3.13) mmHg、(11.18 ± 3.07) mmHg, 两次眼压测量值的差异有统计学意义( t = 22.126, P = 0.000) 。两组的实验眼滴眼后的眼压均呈一致性的下降。结论: 泪膜的改变可以使 Goldmann 压平眼压计的测量值产生偏差。
Purpose: To explore the effect of tear film changes on the intraocular pressure (IOP) measurement by Goldmann applantion tonometer.Methods: Sixty-eight normal subjects were randomly divided into two groups (Gruop A and B) , 34 in each group. One eye of each subject by random selection was given Dextran (in Group A) and Viscoat (in Group B) , respectively. And the fellow eyes were used as controls. IOP was measured in all subjects twice using Goldmann applantion tonometer. And the difference between first and second measurements was compared.Result: In the control eyes of Group A, the average IOP of first and second measurements were (14.44 ± 2.68) mmHg (1 mmHg= 0.133 KPa) and (14.47 ± 2.69) mmHg, there was no difference between the two measurements (t =- 0.329, P = 0.744) . In eyes given Dextran, the average IOP of two measurements were (14.41 ± 2.63) mmHg and (12.94 ± 2.59) mmHg, there was significant difference between the two mea-surements (t =13.949, P= 0.000) . In control eyes of Group B, the average IOP of first and second measurements were (14.53 ± 3.13) mmHg and (11.18 ± 3.07) mmHg, and there was no difference between the two measurements (t = -0.466, P = 0.644) . In eyes given Viscoat, the average IOP of two measurements were (14.53 ± 3.13) mmHg and (11.18 ± 3.07) mmHg, and there was significant difference between the two measurements (t = 22.126, P = 0.000) . After being given Dextran or Viscoat, the IOP values decreased consistently in both Group A and Group B.Conclusions: The change of tear film components can affect IOP values by Goldmann applantion tonometer.
目的：比较四种不同原理的仪器在暗室中对年龄相关性白内障患者Kappa角测量的一致性。方法：对年龄相关性白内障术前60例(60只眼)，暗室中适应10 min后，分别应用iTrace视觉分析仪、Pentacam HR、Lenstar900、IOLMaster700测量瞳孔直径和Kappa角。四种仪器间所测量的数据比较采用单因素方差分析检验和Kruskal-Wallis非参数检验，一致性比较采用Bland-Altman分析。结果：iTrace、Pentacam HR、Lenstar900、IOLMaster700测量瞳孔直径分别为(4.64±0.71) mm，(2.96±0.47) mm，(4.86±0.76) mm，(4.66±0.92) mm；Kappa角大小分别为(0.227±0.121) mm，(0.161±0.09) mm，(0.2±0.124) mm，(0.203±0.104) mm；大于0.5 mm的Kappa角比例分比为3.33%、3.33%、1.67%、1.67%；Pentacam和iTrace的Kappa角测量结果有统计学意义(P=0.001)，Pentacam和Lenstar900、IOLMaster700的Kappa角测量结果差异无统计学意义(P=0.044，0.036)，其他三种仪器之间Kappa角测量结果差异均无统计学意义(P=0.181，0.245，0.860)； 60例被检测者对iTrace、PentacamHR、Lenstar900、IOLMaster700四种仪器测量过程中光强度主观评分结果显示60例(100%)被检测者认为Pentacam HR在测量过程中有明显的不适感，40例(66.67%)被检测者认为IOLMaster700检测过程中舒适感最好，结果差异有统计学意义(χ2=191.236，P<0.001)。结论：Pentacam HR与iTrace、Lenstar900和IOLMaster700三种仪器在暗室中Kappa角的测量结果一致性稍差，临床上需谨慎替换使用。
Objective: To compare the consistency of Kappa Angle measurements in patients with age-related cataracts using four instruments of different principles in a dark room. Methods: Sixty cases (60 eyes) of age-related cataract were adapted in the darkroom for 10 minutes. The pupil size and angle Kappa were measured by iTrace, Pentacam HR, Lenstar900 and IOLMaster700. One-way ANOVA test and Kruskal-Wallis nonparametric test were used to compare the measured data among the four instruments, and Bland-Altman analysis was used for consistency comparison. Results: The measured pupil diameters of iTrace, Pentacam HR, Lenstar900 and IOLmaster700 were 4.64±0.71 mm, 2.96±0.47 mm, 4.86±0.76 mm and 4.66±0.92 mm. The Angle Kappa sizes were 0.227±0.121 mm, 0.161± 0.09 mm, 0.2±0.124 mm, 0.203±0.104 mm. The proportion of angle Kappa larger than 0.5 mm was 3.33%, 3.33%, 1.67% and 1.67%. The measurement results of angle Kappa between Pentacam and iTrace were statistically significant (P=0.001). There was no significant difference in the measurement results of angle Kappa between Pentacam and Lenstar900, Pentacam HR and IOL-Master700 (P=0.044, 0.036). There was no significant difference in the results of angle Kappa measurement among the other three instruments. The subjective score of light intensity in the process of measurement of iTrace, Pentacam HR, Lenstar900 and IOLMaster700 showed that during the process of measurement, 60 cases (100%) experienced obvious discomfort caused by the light intensity in Pentacam HR, while 40 cases (66.67%) felt comfort in IOLMaster700. The differences among the subjective score of light intensity of four instruments were statistically significant (P<0.001). Conclusion: The consistency of the measurement results of Kappa angle between Pentacam HR and iTrace, Lenstar900, IOLMaster700 in the darkroom is relatively poor, so it is necessary to be careful to replace them in clinic.
近视防控已经上升为国家战略，眼轴长度是近视防控的重要建档参数。眼轴长度的测量有多种方法，受到年龄、性别、脉络膜厚度等因素的影响。目前，眼轴长度的定义尚未统一，建议建立标准化的定义和方法学，以指导近视防控的临床和科研工作。
The prevention and control of myopia has become a national strategy, and the axial length is an important parameter in the documentation of myopia prevention and control. This review summarized the measurement technology and factors associated with axial length. Axial length can be measured in various ways and can be influenced by age, gender, choroidal thickness, and other factors. A standardized definition of axial length is warranted to be established for clinical and scientific purposes.
目的：评价不同操作者使用视网膜自动图像分析(automated retinal image analyzer，ARIA)软件测量糖尿病患者视网膜血管管径和迂曲度的重复性和再现性。方法：采用前瞻性诊断性试验研究设计，由2名熟练操作者应用ARIA软件对49名糖尿病患者以视盘为中心的45°数码眼底彩照进行视网膜血管半自动分析。通过测量距离视盘0.5~1.0个视盘直径内的视网膜动静脉血管参数，各选取6条最粗的动静脉综合计算得到中央动脉管径当量(central retinal artery equivalent，CRAE)、视网膜中央静脉管径当量(central retinal vein equivalent，CRVE)、视网膜动静脉比值(arteriole-to-venule ratio，AVR)、平均视网膜动脉迂曲度(mean retinal arteriolar tortuosity，MRAT)、平均视网膜静脉迂曲度(mean retinal venular tortuosity，MRVT)。在此基础上，评价同一操作者与不同操作者间测量结果的重复性和再现性，并绘制Bland-Altman图进行一致性分析。结果：操作者A两次测量的CRAE、CRVE、AVR差异无统计学意义(t= -0.089、-1.425、1.214，均P>0.05)，重复性良好(ICC≥0.725)且高度正相关(r≥0.721)。操作者A与操作者B对同一受试者2次测量的CRAE、CRVE、AVR差异无统计学意义(t= -1.169、-0.050、0.941，均P>0.05)，再现性良好(ICC≥0.750)且高度正相关( r≥0.697)。同一操作者和不同操作者间的MR AT、MRVT差异无统计学意义(P≥0.05)，Spearman非参数相关性分析重复性和再现性较好(r≥0.571，r≥0.588，均P<0.01)。结论：利用ARIA软件测量糖尿病患者视网膜血管管径及迂曲度具有良好的重复性和再现性。
Objective: To assess the repeatability and reproducibility in measurements of retinal vessel diameter and tortuosity in diabetic patients using the Automated Retinal Image Analyzer (ARIA). Methods: A prospective diagnostic trial was performed; 2 skilled researchers performed a semi-automatic analysis of retinal vessels in digital color fundus photography (45° field of view centered on the optic disc) from 49 diabetic patients using ARIA software. Six largest arterioles and venules coursing through an area of 0.5–1.0 disc diameter surrounding the optic disc were selected. Then the retinal vessel parameters were calculated into the central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), arteriole-to-venule ratio (AVR), mean retinal arteriolar tortuosity (MRAT) and mean retinal venular tortuosity (MRVT). To evaluate the repeatability of those values in 2 measurements by the same researcher and the reproducibility between different researchers. Bland-Altman analysis was employed to assess the agreement of the outcomes. Results: There was no significant difference in the CRAE, CRVE, and AVR values in the two-time measurements of researcher A (t= -0.089, -1.425 and 1.214, all P>0.05). It also showed a good repeatability and a highly positive correlation (ICC≥0.725, r≥0.721). There was no significant difference in those measurements between researcher A and B (t= -1.169, -0.050, 0.941, all P>0.05). It also showed a good reproducibility and a highly positive correlation (ICC≥0.750, r≥0.697). Results showed that there was no significant difference in the MRAT and MRVT values both in intraobserver and interobserver measurements (P≥0.05). Besides, Spearman’s nonparametric correlation analysis showed good repeatability and reproducibility (r≥0.571, r≥0.588, all P<0.01). Conclusion: ARIA software yields good repeatability and reproducibility in the measurements of retinal vessel diameter and tortuosity in diabetic patients.
目的：评价StarEyes 900(万灵帮桥，中国)与IOLMaster 500(蔡司，德国)2种眼科光学生物测量仪测量健康受试者眼部参数的差异性、相关性及一致性。方法：前瞻性观察2021年6月至7月于中山大学中山眼科中心进行眼部检查的62例健康受试者共124只眼，分别通过StarEyes 900与IOLMaster 500完成眼轴长度(axial length，AL)、最小角膜屈光力径线上角膜曲率(keratometry for the flattest meridian，Kf)、最大角膜屈光力径线上角膜曲率(keratometry for the steepest meridian，Ks)、平均角膜曲率(mean keratometry，Km)、角膜白到白直径(white-to-white corneal diameter，WTW)等参数的测量，采用配对t检验、Pearson相关分析和Bland-Altman法对其测量结果的差异进行评价。结果：StarEyes 900与IOLMaster 500测量的AL分别为(24.18±1.08) mm和(24.16±1.08) mm；Kf分别为(42.84±1.65) D和(43.04±1.57) D；Ks分别为(44.34±1.90) D和(44.17±1.80) D；Km分别为(43.59±1.73) D和(43.61±1.64) D；WTW分别为(11.64±0.29) mm和(11.64±0.30) mm。StarEyes 900与IOLMaster 500在测量Km、WTW时，其差异无统计学意义(P>0.05)，而在AL、Kf、Ks的测量上差异有统计学意义(P<0.01)。其中StarEyes 900所测的AL和Ks值大于IOLMaster 500，而Kf、Km和WTW值则小于IOLMaster 500。经Pearson相关分析，2种仪器的测量结果均表现出较高的相关性；经Bland-Altman法评价，2种仪器的测量结果均表现出较高的一致性。结论：StarEyes 900与IOLMaster 500测量的Km、WTW均表现出较高的一致性，2种方法可互为参考；测量的AL、Kf、Ks存在的差异具有统计学意义；各项参数的测量均具有较好的相关性和一致性。
Objective: To evaluate the difference, correlation and agreement of eye parameters measured by StarEyes 900 visual function analyzer (Wan Ling Bang Qiao, China) and IOLMaster 500 (Carl Zeiss, Germany) swept-source optical coherence tomography biometer. Methods: A prospective study was designed involving 62 healthy subjects (124 eyes) undergoing ophthalmic examinations in Zhongshan Ophthalmic Center from June 2021 to July 2021. Data from their both eyes were selected for analysis in all patients. Axial length (AL), keratometry for the steepest meridian (Ks), keratometry for the flattest meridian (Kf), mean keratometry (Km) and corneal diameter (WTW) were measured by the StarEyes 900 visual function analyzer and IOLMaster 500 swept-source optical coherence tomography biometer. A paired t-test was used to analyze the differences in measurement results. The Pearson correlation coefficient was used to analyze the correlation. Bland-Airman method was used to assess the agreement of the instruments. Results: The AL, Kf, Ks, Km and WTW obtained by StarEyes 900 and IOLMaster 500 were (24.18±1.08) mm and (24.16±1.08) mm, (42.84±1.65) D and (43.04±1.57) D, (44.34±1.90) D and (44.17±1.80) D, (43.59±1.73) D and (43.61±1.64) D, and (11.64±0.29) mm and (11.64±0.30) mm, respectively. The Km and WTW of the two devices showed no significant difference (P>0.05), while the AL, Ks and Kf showed significant differences (all P<0.01). The AL and Ks obtained by StarEyes 900 were higher than by IOLMaster 500, while the Kf, Km and WTW were lower. The measurements of five aforementioned biometric parameters by both devices showed good correlation by Pearson correlation coefficient and good agreement by Bland-Airman. Conclusion: The Km and WTW measured by the two devices showed no significant difference, and provided references to one another. The difference in AL, Kf and Ks between the two devices showed significant differences. All of the measurements showed good correlation by Pearson correlation coefficient and good agreement by Bland-Airman.
