AIM: To evaluate the repeatability of central corneal thickness (CCT) measurement by entacam, and agreement of CCT measured by Pentacam and ultrasound pachymetry (USP) in Chinese myopia. Thereby investigate the possib...AIM: To evaluate the repeatability of central corneal thickness (CCT) measurement by entacam, and agreement of CCT measured by Pentacam and ultrasound pachymetry (USP) in Chinese myopia. Thereby investigate the possibility of Pentacam as a substitute for USP in CCT measurement before refractive surgery. The effects of corneal curvature measured by Pentacam on CCT were also evaluated. METHODS: One hundred and forty-eight right eyes of 148 individual with myopia were included in this study. Three successive Pentacam CCT measurements followed by 10 successive ultrasound pachymetry were carried out in the 148 eyes. Mean of CCT taken by each device was calculated for comparison. According to the CCT measured by USP, all the 148 eyes were divided into 3 groups: <520 mu m, 520-560 mu m, >560 mu m. For all eyes and each group the CCT obtained by Pentacam and USP were compared. Anterior corneal curvature of the 148 eyes was also adopted for correlation analysis with CCT obtained by ultrasound pachymetry. In addition, CCT measurement using 60 random selected Scheimpflug images was performed by 3 skilled investigators at different time, and this was repeated for 3 times by a forth investigator to assess repeatability of Pentacam CCT measurement using Scheimpflug images. RESULTS: Intraclass correlation coefficient (ICC) analysis revealed high intraobserver repeatability (ICC=0.994, F=158.60, P<0.001) for CCT measurement by Pentacam. The interobserver (ICC=0.998, F =494.73, P <0.001) and intraobserver (ICC=0.997, F=383.98, P<0.001) repeatability for Pentacam CCT measurements using Scheimpflug images were also excellent. There was high positive correlation between the CCT values measured by Pentacam and ultrasound pachymetry (r=0.963, P<0.001). Bland-altman plots showed that the Pentacam underestimate the CCT by 8.02 mu m compared with ultrasouond pachymetry.The differences between Pentacam and USP increased as the CCT readings by USP increased (Pentacam vs USP: slope=-0.04, P< 0.05). The 95% upper and lower limits of agreement between CCT values obtained from the two devices were +9. 33 mu m and -25.37 mu m. No significant association could be found between CCT and anterior corneal curvature. CONCLUSION: Inter- and intraobserver variability for CCT measurements by Pentacam was considerably below clinically significant levels. CCT of myopia obtained by Scheimpflug camera, Pentacam, were highly correlated to that by ultrasound pachymetry. However, the values obtained are not directly interchangeable between Pentacam and ultrasound pachymetry as the 95% limits of agreement are relatively wide. Pentacam can be a useful instrument for measuring CCT in candidates to refractive surgery in clinic.展开更多
AIM: To determine the repeatability and agreement of stereoacuity measurements made using some of the most widely used clinical tests: Frisby, TNO, Randot and Titmus.METHODS: Stereoacuity was measured in two different...AIM: To determine the repeatability and agreement of stereoacuity measurements made using some of the most widely used clinical tests: Frisby, TNO, Randot and Titmus.METHODS: Stereoacuity was measured in two different sessions separated by a time interval of at least 24 h but no longer than 1wk in 74 subjects of mean age 20.6y using the four methods. The study participants were divided into two groups: subjects with normal binocular vision and subjects with abnormal binocular vision.RESULTS: Best repeatability was shown by the Frisby and Titmus [coefficient of repeatability(COR): ±13 and±12s arc respectively] in the subjects with normal binocular vision though a clear ceiling effect was noted.In the subjects with abnormal binocular vision, best repeatability was shown by the Frisby(COR: ±69s arc)and Randot(COR: ±72s arc). In both groups, the TNO test showed poorest agreement with the other tests.CONCLUSION:Therepeatabilityofstereoacuitymeasures was low in subjects with poor binocular vision yet fairly good in subjects with normal binocular vision with the exception of the TNO test. The reduced agreement detected between the tests indicates they cannot be used interchangeably.展开更多
AIM: To evaluate the intra-operator repeatability of time domain and swept-source Fourier domain anterior segment optical coherence tomography(AS-OCT), namely, Visante ASOCT and Casia SS-1000 OCT, in measuring the pre...AIM: To evaluate the intra-operator repeatability of time domain and swept-source Fourier domain anterior segment optical coherence tomography(AS-OCT), namely, Visante ASOCT and Casia SS-1000 OCT, in measuring the preoperative parameters of implantable collamer lens(ICL) in myopic eyes, as well as the agreement between the two devices.METHODS: A total of 97 eyes from 49 myopes were investigated in this prospective case series study. The anterior chamber depth(ACD), angle-to-angle distance(ATA), pupil diameter(PD) and crystalline lens rise(CLR) in all subjects were measured for three times during one session by the same operator. The repeatability was evaluated using the within-subject standard deviation(Sw), repeatability limits and intraclass correlation coefficients(ICC). The agreement between the two systems was evaluated using the Bland-Altman plots and 95% limits of agreement(Lo A).RESULTS: The repeatability limits of Visante AS-OCT in measuring ACD, ATA, PD and CLR were 0.099, 0.141, 0.304, and 0.079 mm, respectively. The repeatability limits of Casia SS-1000 OCT in measuring ACD, ATA, PD, and CLR were 0.105, 0.127, 0.357, and 0.082 mm, respectively. Excellent repeatability could be attained in both devices, with the ICC>0.8 for all the measured variables. The interdevice agreement was excellent(P>0.05) for ACD and ATA, but poor(P<0.05) for PD and CLR.CONCLUSION: Good repeatability can be attained by time domain and swept-source Fourier-domain OCT for all the measured variables. Moreover, interdevice agreement analysis suggests that interchangeable measurements between two devices can be achieved for ACD and ATA, but not for PD and CLR;but the differences in measurements were not clinically significant.展开更多
目的:探讨Pentacam眼前节分析仪和Keratron Scout角膜地形图仪测量Kappa角的一致性,评价两种仪器测量结果的重复性。方法:前瞻性随机对照研究。选取2018-01-01/30在我院眼视光中心行近视术前检查的患者69例,所有受试者由同一检查者分别...目的:探讨Pentacam眼前节分析仪和Keratron Scout角膜地形图仪测量Kappa角的一致性,评价两种仪器测量结果的重复性。方法:前瞻性随机对照研究。选取2018-01-01/30在我院眼视光中心行近视术前检查的患者69例,所有受试者由同一检查者分别采用Pentacam和Keratron Scout重复测量3次,以(X ,Y)坐标形式记录Kappa角的大小,采用组内相关系数(ICC)、Cronbach s Alpha系数评价两种仪器测量Kappa角的重复性;t 检验比较两种仪器测量结果的差异,Pearson相关分析其相关性;Bland-Altman图评估两种仪器测量结果的一致性。结果:3次重复测量时,两种仪器均表现出很好的重复性,两种仪器测得Kappa角差异无统计学意义( X 值: P =0.17;Y 值: P =0.61),Pearson相关分析表明Kappa角大小具有相关性(X 值: r =0.90, P <0.01;Y 值: r =0.91, P <0.01)。Bland-Altman图显示 X 值和 Y 值95%一致性区间分别为-0.11~0.14mm和-0.10~0.11mm。结论:Pentacam眼前节分析仪和Keratron Scout角膜地形图仪测量角膜屈光手术患者Kappa角重复性好,两种仪器测量的Kappa角结果一致性好,可以相互验证。展开更多
目的比较激光扫描共聚焦显微镜测量中央区和涡状区角膜上皮基底神经丛结果的一致性,从而筛选出更加合理可靠的检查部位。方法前瞻性研究。2018年11月至2019年2月募集年龄在20~40岁的健康志愿者30人作为研究对象,所有受试者经过筛查排除...目的比较激光扫描共聚焦显微镜测量中央区和涡状区角膜上皮基底神经丛结果的一致性,从而筛选出更加合理可靠的检查部位。方法前瞻性研究。2018年11月至2019年2月募集年龄在20~40岁的健康志愿者30人作为研究对象,所有受试者经过筛查排除影响神经功能的全身和局部病变后纳入本研究。入组受试者均选择右眼为受检眼,由2名经验丰富的医师完成3次激光扫描共聚焦显微镜检查。首先于受试当天由操作者A和操作者B各完成1次检查,1周后再由操作者A重复检查1次。所得图像用Adobe Photoshop图像处理软件拼接后,再用Neuron J图像分析软件进行定量分析,得到神经纤维长度(nerve fiber length,NFL)(mm·mm^-2)。然后分别根据涡状区和中央区NFL值绘制Bland-Altman散点图,并计算重复性系数(coefficient of repeatability,CoR)和95%一致性区间(limit of agreement,LOA),用于评估两个部位观察者内和观察者间一致性。结果所有受检眼均可于角膜中央偏鼻下方查见涡状结构,重复检查获得的涡状区图像显示角膜神经形态稳定,中央区图像显示角膜神经形态变异较大。涡状区一致性分析观察者内CoR值为6.6%,观察者间CoR值为6.1%,一致性很高;而中央区一致性分析观察者内CoR值为44.1%,观察者间CoR值为31.8%,一致性较差。Bland-Altman散点图涡状区观察者内和观察者间测量差值均聚集于“0”刻度线附近,且95%LOA较窄,均在平均NFL的1个标准差的区间内,一致性良好;中央区观察者内和观察者间测量差值分布较分散,95%LOA较宽,约为两次检查平均NFL标准差的2~3倍,一致性较差。结论涡状结构在健康人角膜上皮基底神经丛普遍存在,其形态特殊,位置固定,在图像采集时能够作为明确的角膜标记物;涡状区图像重复测量一致性良好,可以应用于角膜上皮基底神经丛的定量分析。展开更多
文摘AIM: To evaluate the repeatability of central corneal thickness (CCT) measurement by entacam, and agreement of CCT measured by Pentacam and ultrasound pachymetry (USP) in Chinese myopia. Thereby investigate the possibility of Pentacam as a substitute for USP in CCT measurement before refractive surgery. The effects of corneal curvature measured by Pentacam on CCT were also evaluated. METHODS: One hundred and forty-eight right eyes of 148 individual with myopia were included in this study. Three successive Pentacam CCT measurements followed by 10 successive ultrasound pachymetry were carried out in the 148 eyes. Mean of CCT taken by each device was calculated for comparison. According to the CCT measured by USP, all the 148 eyes were divided into 3 groups: <520 mu m, 520-560 mu m, >560 mu m. For all eyes and each group the CCT obtained by Pentacam and USP were compared. Anterior corneal curvature of the 148 eyes was also adopted for correlation analysis with CCT obtained by ultrasound pachymetry. In addition, CCT measurement using 60 random selected Scheimpflug images was performed by 3 skilled investigators at different time, and this was repeated for 3 times by a forth investigator to assess repeatability of Pentacam CCT measurement using Scheimpflug images. RESULTS: Intraclass correlation coefficient (ICC) analysis revealed high intraobserver repeatability (ICC=0.994, F=158.60, P<0.001) for CCT measurement by Pentacam. The interobserver (ICC=0.998, F =494.73, P <0.001) and intraobserver (ICC=0.997, F=383.98, P<0.001) repeatability for Pentacam CCT measurements using Scheimpflug images were also excellent. There was high positive correlation between the CCT values measured by Pentacam and ultrasound pachymetry (r=0.963, P<0.001). Bland-altman plots showed that the Pentacam underestimate the CCT by 8.02 mu m compared with ultrasouond pachymetry.The differences between Pentacam and USP increased as the CCT readings by USP increased (Pentacam vs USP: slope=-0.04, P< 0.05). The 95% upper and lower limits of agreement between CCT values obtained from the two devices were +9. 33 mu m and -25.37 mu m. No significant association could be found between CCT and anterior corneal curvature. CONCLUSION: Inter- and intraobserver variability for CCT measurements by Pentacam was considerably below clinically significant levels. CCT of myopia obtained by Scheimpflug camera, Pentacam, were highly correlated to that by ultrasound pachymetry. However, the values obtained are not directly interchangeable between Pentacam and ultrasound pachymetry as the 95% limits of agreement are relatively wide. Pentacam can be a useful instrument for measuring CCT in candidates to refractive surgery in clinic.
基金Supported by the Direction General of Universities and Research(DGUI)of the Community of Madrid(No.CCG10-UCM/BIO-4889)
文摘AIM: To determine the repeatability and agreement of stereoacuity measurements made using some of the most widely used clinical tests: Frisby, TNO, Randot and Titmus.METHODS: Stereoacuity was measured in two different sessions separated by a time interval of at least 24 h but no longer than 1wk in 74 subjects of mean age 20.6y using the four methods. The study participants were divided into two groups: subjects with normal binocular vision and subjects with abnormal binocular vision.RESULTS: Best repeatability was shown by the Frisby and Titmus [coefficient of repeatability(COR): ±13 and±12s arc respectively] in the subjects with normal binocular vision though a clear ceiling effect was noted.In the subjects with abnormal binocular vision, best repeatability was shown by the Frisby(COR: ±69s arc)and Randot(COR: ±72s arc). In both groups, the TNO test showed poorest agreement with the other tests.CONCLUSION:Therepeatabilityofstereoacuitymeasures was low in subjects with poor binocular vision yet fairly good in subjects with normal binocular vision with the exception of the TNO test. The reduced agreement detected between the tests indicates they cannot be used interchangeably.
基金Supported by the Priming Scientific Research Foundation for the junior researcher in Beijing Tongren Hospital,Capital Medical University(No.2018-YJJ-ZZL-034)。
文摘AIM: To evaluate the intra-operator repeatability of time domain and swept-source Fourier domain anterior segment optical coherence tomography(AS-OCT), namely, Visante ASOCT and Casia SS-1000 OCT, in measuring the preoperative parameters of implantable collamer lens(ICL) in myopic eyes, as well as the agreement between the two devices.METHODS: A total of 97 eyes from 49 myopes were investigated in this prospective case series study. The anterior chamber depth(ACD), angle-to-angle distance(ATA), pupil diameter(PD) and crystalline lens rise(CLR) in all subjects were measured for three times during one session by the same operator. The repeatability was evaluated using the within-subject standard deviation(Sw), repeatability limits and intraclass correlation coefficients(ICC). The agreement between the two systems was evaluated using the Bland-Altman plots and 95% limits of agreement(Lo A).RESULTS: The repeatability limits of Visante AS-OCT in measuring ACD, ATA, PD and CLR were 0.099, 0.141, 0.304, and 0.079 mm, respectively. The repeatability limits of Casia SS-1000 OCT in measuring ACD, ATA, PD, and CLR were 0.105, 0.127, 0.357, and 0.082 mm, respectively. Excellent repeatability could be attained in both devices, with the ICC>0.8 for all the measured variables. The interdevice agreement was excellent(P>0.05) for ACD and ATA, but poor(P<0.05) for PD and CLR.CONCLUSION: Good repeatability can be attained by time domain and swept-source Fourier-domain OCT for all the measured variables. Moreover, interdevice agreement analysis suggests that interchangeable measurements between two devices can be achieved for ACD and ATA, but not for PD and CLR;but the differences in measurements were not clinically significant.
文摘目的:探讨Pentacam眼前节分析仪和Keratron Scout角膜地形图仪测量Kappa角的一致性,评价两种仪器测量结果的重复性。方法:前瞻性随机对照研究。选取2018-01-01/30在我院眼视光中心行近视术前检查的患者69例,所有受试者由同一检查者分别采用Pentacam和Keratron Scout重复测量3次,以(X ,Y)坐标形式记录Kappa角的大小,采用组内相关系数(ICC)、Cronbach s Alpha系数评价两种仪器测量Kappa角的重复性;t 检验比较两种仪器测量结果的差异,Pearson相关分析其相关性;Bland-Altman图评估两种仪器测量结果的一致性。结果:3次重复测量时,两种仪器均表现出很好的重复性,两种仪器测得Kappa角差异无统计学意义( X 值: P =0.17;Y 值: P =0.61),Pearson相关分析表明Kappa角大小具有相关性(X 值: r =0.90, P <0.01;Y 值: r =0.91, P <0.01)。Bland-Altman图显示 X 值和 Y 值95%一致性区间分别为-0.11~0.14mm和-0.10~0.11mm。结论:Pentacam眼前节分析仪和Keratron Scout角膜地形图仪测量角膜屈光手术患者Kappa角重复性好,两种仪器测量的Kappa角结果一致性好,可以相互验证。
文摘目的比较激光扫描共聚焦显微镜测量中央区和涡状区角膜上皮基底神经丛结果的一致性,从而筛选出更加合理可靠的检查部位。方法前瞻性研究。2018年11月至2019年2月募集年龄在20~40岁的健康志愿者30人作为研究对象,所有受试者经过筛查排除影响神经功能的全身和局部病变后纳入本研究。入组受试者均选择右眼为受检眼,由2名经验丰富的医师完成3次激光扫描共聚焦显微镜检查。首先于受试当天由操作者A和操作者B各完成1次检查,1周后再由操作者A重复检查1次。所得图像用Adobe Photoshop图像处理软件拼接后,再用Neuron J图像分析软件进行定量分析,得到神经纤维长度(nerve fiber length,NFL)(mm·mm^-2)。然后分别根据涡状区和中央区NFL值绘制Bland-Altman散点图,并计算重复性系数(coefficient of repeatability,CoR)和95%一致性区间(limit of agreement,LOA),用于评估两个部位观察者内和观察者间一致性。结果所有受检眼均可于角膜中央偏鼻下方查见涡状结构,重复检查获得的涡状区图像显示角膜神经形态稳定,中央区图像显示角膜神经形态变异较大。涡状区一致性分析观察者内CoR值为6.6%,观察者间CoR值为6.1%,一致性很高;而中央区一致性分析观察者内CoR值为44.1%,观察者间CoR值为31.8%,一致性较差。Bland-Altman散点图涡状区观察者内和观察者间测量差值均聚集于“0”刻度线附近,且95%LOA较窄,均在平均NFL的1个标准差的区间内,一致性良好;中央区观察者内和观察者间测量差值分布较分散,95%LOA较宽,约为两次检查平均NFL标准差的2~3倍,一致性较差。结论涡状结构在健康人角膜上皮基底神经丛普遍存在,其形态特殊,位置固定,在图像采集时能够作为明确的角膜标记物;涡状区图像重复测量一致性良好,可以应用于角膜上皮基底神经丛的定量分析。
