Retina Division, Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
JAMA Ophthalmol. 2018 Mar 1;136(3):286-290. doi: 10.1001/jamaophthalmol.2017.6290.
The Early Treatment Diabetic Retinopathy Study (ETDRS) alphabet chart is not feasible for measuring best-corrected visual acuity (BCVA) for individuals who are unfamiliar with the Roman alphabet. The ETDRS Landolt C chart is an alternative, but it may not reflect true BCVA among those with confusion between left and right. The ETDRS number chart might overcome these limitations, but little is known regarding its reliability.
To evaluate repeatability and agreement of BCVA using the ETDRS number chart or Landolt C chart compared with ETDRS alphabet charts in healthy and diseased eyes.
DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional study was conducted in Thailand from July 1, 2015, to June 30, 2016, among 154 adult Thai individuals. Those who could read Roman alphabets were classified into the following 4 groups, using 1 eye per participant: group A, which comprised 60 healthy eyes (BCVA, 20/20-20/25); group B, which comprised 40 eyes with age-related cataract, diabetic macular edema, or age-related macular degeneration (BCVA, 20/20-20/40); group C, which comprised 40 eyes with age-related cataract, diabetic macular edema, or age-related macular degeneration (BCVA, 20/50-20/100); and group D, which comprised 14 eyes with age-related cataract, diabetic macular edema, or age-related macular degeneration (BCVA, 20/125-20/200).
Two standardized 4-m BCVA measurements with 3 different Precision Vision ETDRS charts (PV number, Landolt C, and alphabet), in random sequence, performed 30 minutes apart.
Repeatability, agreement, and testing duration of BCVA.
Of 154 Thai participants (82 women and 72 men; mean [SD] age, 52.9 [18.2] years), the ETDRS number chart had strong repeatability coefficients (group A, 0.61 [95% CI, 0.42-0.75]; group B, 0.87 [95% CI, 0.78-0.93]; group C, 0.81 [95% CI, 0.67-0.90]; and group D, 0.81 [95% CI, 0.49-0.94]). Concordance correlation coefficients between the number and alphabet charts were also strong (group A, 0.89 [95% CI, 0.82-0.93]; group B, 0.97 [95% CI, 0.94-0.98]; group C, 0.92 [95% CI, 0.86-0.96]; and group D, 0.96 [95% CI, 0.87-0.99]), while the concordance correlation coefficients between the Landolt C and alphabet charts were lower (group A, 0.72 [95% CI, 0.52-0.83]; group B, 0.83 [95% CI, 0.68-0.91]; group C, 0.79 [95% CI, 0.61-0.89]; and group D, 0.89 [95% CI, 0.66-0.97]). The mean letter score difference between the number and alphabet charts was 1 (95% limits of agreement, -4 to +6) compared with -7 (95% limits of agreement, -18 to +5; P < .001) between the Landolt C and alphabet charts.
The repeatability coefficients and concordance correlation coefficients suggest that ETDRS number charts are viable for measuring BCVA in clinical practice and trials for individuals who are unfamiliar with the Roman alphabet.
对于不熟悉罗马字母的人来说，早期糖尿病视网膜病变研究（ETDRS）字母图表并不适合测量最佳矫正视力（BCVA）。ETDRS 兰多克 C 图表是一种替代方法，但对于左右混淆的人来说，它可能无法反映真实的 BCVA。ETDRS 数字图表可能克服这些限制，但对于其可靠性知之甚少。
评估在健康和患病眼中，与 ETDRS 字母图表相比，使用 ETDRS 数字图表或兰多克 C 图表测量 BCVA 的重复性和一致性。
设计、地点和参与者：这是一项在泰国进行的横断面研究，于 2015 年 7 月 1 日至 2016 年 6 月 30 日期间纳入了 154 名成年泰国人。那些能够阅读罗马字母的人被分为以下 4 组，每组使用一只眼睛：组 A，包括 60 只健康眼睛（BCVA，20/20-20/25）；组 B，包括 40 只患有年龄相关性白内障、糖尿病性黄斑水肿或年龄相关性黄斑变性的眼睛（BCVA，20/20-20/40）；组 C，包括 40 只患有年龄相关性白内障、糖尿病性黄斑水肿或年龄相关性黄斑变性的眼睛（BCVA，20/50-20/100）；组 D，包括 14 只患有年龄相关性白内障、糖尿病性黄斑水肿或年龄相关性黄斑变性的眼睛（BCVA，20/125-20/200）。
在 30 分钟的间隔内，使用 3 种不同的 Precision Vision ETDRS 图表（PV 数字、兰多克 C 和字母）进行了 2 次标准化的 4 米 BCVA 测量。
BCVA 的重复性、一致性和测试时间。
在 154 名泰国参与者（82 名女性和 72 名男性；平均[标准差]年龄，52.9[18.2]岁）中，ETDRS 数字图表具有较强的重复性系数（组 A，0.61[95%置信区间，0.42-0.75]；组 B，0.87[95%置信区间，0.78-0.93]；组 C，0.81[95%置信区间，0.67-0.90]；组 D，0.81[95%置信区间，0.49-0.94]）。数字和字母图表之间的一致性相关系数也很强（组 A，0.89[95%置信区间，0.82-0.93]；组 B，0.97[95%置信区间，0.94-0.98]；组 C，0.92[95%置信区间，0.86-0.96]；组 D，0.96[95%置信区间，0.87-0.99]），而兰多克 C 和字母图表之间的一致性相关系数较低（组 A，0.72[95%置信区间，0.52-0.83]；组 B，0.83[95%置信区间，0.68-0.91]；组 C，0.79[95%置信区间，0.61-0.89]；组 D，0.89[95%置信区间，0.66-0.97]）。数字和字母图表之间的平均字母分数差异为 1（95%置信区间的界限，-4 至+6），而兰多克 C 和字母图表之间的差异为-7（95%置信区间的界限，-18 至+5；P < 0.001）。
重复系数和一致性相关系数表明，ETDRS 数字图表在不熟悉罗马字母的个体的临床实践和试验中，可用于测量 BCVA。
