Abstract：
OBJECTIVE: Clinicians measure the near point of convergence (NPC) and the amplitude of accommodation (AA) from the spectacle plane, the bridge of the nose or the lateral canthus when assessing visual function. These values are compared to standard clinical criteria to diagnose vergence and accommodation deficits, despite varying reference points. This prospective study explored measuring relative to the spectacle plane and from the lateral canthus for NPC and monocular AA, and the resulting clinical implications of diagnosing visual deficits.
METHODS: Participants were seen by a single clinician for an eye examination. NPC was measured from the forehead and the lateral canthus of the right eye. Monocular AA was measured from the brow and the lateral canthus. Differences between measurements were analysed using non-parametric statistical tests including Wilcoxon Signed Rank, as well as linear regression and a linear mixed effects model to adjust for inter-eye correlation and repeated measures. Chi-square tests were used to assess differences in rates of abnormal findings.
RESULTS: Data were collected from 70 participants (53% female, median age 13 [11-15] years). On average, measuring NPC from the lateral canthus yielded a value 1.8 cm higher than measuring from the forehead. Measuring AA from the lateral canthus resulted in an average difference of 1.5 cm compared to measuring from the brow. A total of 39% and 76% of subjects failed NPC compared to clinical norms when measured from the forehead or the lateral canthus, respectively, while 7% and 40% failed AA when measured from the brow or the lateral canthus, respectively.
CONCLUSIONS: With the variable anatomy of the eye, it is imperative to account for the measurement point when assessing visual function. Measuring from the lateral canthus greatly increased the failure rates for NPC and AA compared with measuring from the forehead and brow, respectively.
METHODS: Participants were seen by a single clinician for an eye examination. NPC was measured from the forehead and the lateral canthus of the right eye. Monocular AA was measured from the brow and the lateral canthus. Differences between measurements were analysed using non-parametric statistical tests including Wilcoxon Signed Rank, as well as linear regression and a linear mixed effects model to adjust for inter-eye correlation and repeated measures. Chi-square tests were used to assess differences in rates of abnormal findings.
RESULTS: Data were collected from 70 participants (53% female, median age 13 [11-15] years). On average, measuring NPC from the lateral canthus yielded a value 1.8 cm higher than measuring from the forehead. Measuring AA from the lateral canthus resulted in an average difference of 1.5 cm compared to measuring from the brow. A total of 39% and 76% of subjects failed NPC compared to clinical norms when measured from the forehead or the lateral canthus, respectively, while 7% and 40% failed AA when measured from the brow or the lateral canthus, respectively.
CONCLUSIONS: With the variable anatomy of the eye, it is imperative to account for the measurement point when assessing visual function. Measuring from the lateral canthus greatly increased the failure rates for NPC and AA compared with measuring from the forehead and brow, respectively.
摘要：
目的：临床医生从眼镜平面测量近收敛点（NPC）和调节幅度（AA），评估视觉功能时的鼻梁或外侧can。将这些值与标准临床标准进行比较，以诊断聚散度和调节缺陷，尽管参考点不同。这项前瞻性研究探索了NPC和单眼AA相对于眼镜平面和侧眼角的测量，以及诊断视力缺陷的临床意义。
方法：参与者由一名临床医生进行眼部检查。从右眼的前额和侧眼角测量NPC。单眼AA是从眉毛和眼角测量的。使用非参数统计检验分析测量值之间的差异，包括WilcoxonSignedRank，以及线性回归和线性混合效应模型，以调整眼间相关性和重复测量。卡方检验用于评估异常发现率的差异。
结果：数据来自70名参与者（53％为女性，中位年龄13[11-15]岁)。平均而言,从外侧can测量NPC的值比从额头测量的值高1.8cm。与从眉头测量相比，从外侧眼角测量AA的平均差为1.5cm。当从前额或外侧can测量时，与临床规范相比，总共有39％和76％的受试者失败了NPC。分别,从眉毛或眼角测量时，有7％和40％的AA失败，分别。
结论：随着眼睛解剖结构的变化，在评估视觉功能时，必须考虑测量点。与从额头和眉头测量相比，从侧面测量NPC和AA的失败率大大提高。分别。
方法：参与者由一名临床医生进行眼部检查。从右眼的前额和侧眼角测量NPC。单眼AA是从眉毛和眼角测量的。使用非参数统计检验分析测量值之间的差异，包括WilcoxonSignedRank，以及线性回归和线性混合效应模型，以调整眼间相关性和重复测量。卡方检验用于评估异常发现率的差异。
结果：数据来自70名参与者（53％为女性，中位年龄13[11-15]岁)。平均而言,从外侧can测量NPC的值比从额头测量的值高1.8cm。与从眉头测量相比，从外侧眼角测量AA的平均差为1.5cm。当从前额或外侧can测量时，与临床规范相比，总共有39％和76％的受试者失败了NPC。分别,从眉毛或眼角测量时，有7％和40％的AA失败，分别。
结论：随着眼睛解剖结构的变化，在评估视觉功能时，必须考虑测量点。与从额头和眉头测量相比，从侧面测量NPC和AA的失败率大大提高。分别。
