Laboratory of Experimental Ophthalmology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
PLoS One. 2024 Feb 8;19(2):e0288512. doi: 10.1371/journal.pone.0288512. eCollection 2024.
To describe the development and investigate the accuracy of a novel smartphone-based Contrast Sensitivity (CS) application, the K-CS test.
A total of 67 visually impaired and 50 normal participants were examined monocularly using the novel digital K-CS test and the Pelli-Robson (PR) chart. The K-CS test examines letter contrast sensitivity in logarithmic units, using eight levels of contrast from logCS = ~0,1 to logCS = ~2,1 at two spatial frequencies of 1.5 and 3 cycles per degree (cpd). The K-CS test was compared to the gold standard, PR test and intra-session test repeatability was also examined.
The K-CS test in normally sighted was found to agree well with the PR, providing comparable mean scores in logCS (±SD) (K-CS = 1.908 ± 0.06 versus PR = 1.93 ± 0.05) at 1.5 cpd and mean (± SD) logCS at 3 cpd (K-CS = 1.83 ± 0.13 versus PR = 1.86 ± 0.07). The mean best corrected visual acuity of visually impaired participants was 0.67 LogMAR (SD = 0.21) and the K-CS was also found to agree well with the Pelli-Robson in this group, with an equivalent mean (±SD) logCS at 1.5 cpd: (K-CS = 1.19 ± 0.27, PR = 1.15 ± 0.31), 3 cpd: K-CS = 1.01 ± 0.33, PR = 0.94 ± 0.34. Regarding the intra-session test repeatability, both the K-CS test and the PR test showed good repeatability in terms of the 95% limits of agreement (LoA): K-CS = ±0.112 at 1.5 cpd and ±0.133 at 3 cpd, PR = ±0.143 at 1.5 cpd and ±0.183 in 3 cpd in visually impaired individuals.
The K-CS test provides a quick assessment of the CS both in normally sighted and visually impaired individuals. The K-CS could serve as an alternative tool to assess contrast sensitivity function using a smartphone and provides results that agree well with the commonly used PR test.
描述一种新型基于智能手机的对比敏感度（CS）应用程序，即 K-CS 测试的开发并探究其准确性。
共有 67 名视力障碍者和 50 名正常参与者分别使用新型数字 K-CS 测试和 Pelli-Robson（PR）图表进行单眼检查。K-CS 测试以对数单位检查字母对比敏感度，使用从 logCS=0.1 到 logCS=2.1 的八个对比度水平，在两个空间频率 1.5 和 3 个周期/度（cpd）下进行。将 K-CS 测试与金标准 PR 测试进行比较，并检查了同一批次内的测试可重复性。
在正常视力者中，K-CS 测试与 PR 测试结果吻合良好，在 1.5 cpd 时，K-CS 测试的平均（±SD）logCS 得分（K-CS=1.908±0.06 与 PR=1.93±0.05）和 3 cpd 时的平均（±SD）logCS 得分（K-CS=1.83±0.13 与 PR=1.86±0.07）具有可比性。视力障碍者的最佳矫正视力平均值为 0.67 LogMAR（SD=0.21），且 K-CS 测试与该组中的 Pelli-Robson 测试结果也吻合良好，在 1.5 cpd 时具有相同的平均（±SD）logCS 值：（K-CS=1.19±0.27，PR=1.15±0.31），在 3 cpd 时：K-CS=1.01±0.33，PR=0.94±0.34。关于同一批次内的测试可重复性，K-CS 测试和 PR 测试在 95%一致性界限（LoA）方面都显示出良好的可重复性：在 1.5 cpd 时 K-CS=±0.112，在 3 cpd 时 K-CS=±0.133，在视力障碍者中，PR=±0.143 在 1.5 cpd 和±0.183 在 3 cpd。
K-CS 测试可快速评估正常视力者和视力障碍者的 CS。K-CS 可以作为使用智能手机评估对比敏感度功能的替代工具，并提供与常用的 PR 测试结果吻合良好的结果。
