van den Brom H J, Kooijman A C, Blanksma L J, van Rij G
Department of Ophthalmology, University of Groningen, The Netherlands.
Doc Ophthalmol. 1995;90(1):61-6. doi: 10.1007/BF01203295.
To compare two different optotypes to measure visual acuity.
Experiment 1: Fifty patients with moderate cataracts were asked to read a chart consisting of letters of the alphabet (Sloan letters) first and a chart comprising Landolt's broken rings afterwards. Experiment 2: Half of patients were instructed to repeat the reading with a second letter chart, the other half was instructed to read the chart with the broken rings again.
Experiment 1: It was found that with the letter chart more optotypes (two to four) were recognized than with the broken ring chart. The different result of visual acuity measurement with the two optotypes is irrespective of the visual acuity. Experiment 2: The re-read instruction revealed that the measurements were reproduced equally for both charts.
比较两种不同的视标以测量视力。
实验1：50名中度白内障患者先被要求阅读由字母组成的视力表（斯隆字母），之后再阅读包含兰多尔特环的视力表。实验2：一半患者被指示用第二份字母视力表重复阅读，另一半患者被指示再次阅读带缺口环的视力表。
实验1：发现与带缺口环的视力表相比，使用字母视力表能识别更多的视标（两到四个）。两种视标测量视力的不同结果与视力无关。实验2：重新阅读的指示表明，两张视力表的测量结果均可重复性相同。
