ARE THERE TRUE REASONS TO CONSIDER ETDRS CHARTS AS A “GOLDEN STANDARD” FOR MEASURING VISUAL ACUITY?

The charts having different design and containing various optotypes - geometrical forms, sinusoidal gratings letters, figures, simplified object images, textual fragments - are used traditionally in clinical practice for visual acuity assessment. Visual tasks are also various: detection, localization, recognition, reading. The visual acuity values obtained by means of each chart reflect inevitably not only the quality of the images created on the photoreceptor matrix, but also functioning of different brain path- ways tuned to the images of different types. The choice of the chart depends on the aim of measurement. Despite evident impossibility of creating a universal chart, the best in all respects, recently, there appeared a tendency to promote ETDRS charts with letters into clinical and educational practice as some “gold standard” for measuring visual acuity. However, objective optometric qualities of the ETDRS charts as the instruments for clinical examination - comfort of the procedure, accuracy of measurements, test-retest reliability - are not better than of many other charts and their usefulness is limited. In the present work, some shortages of the ETDRS charts are discussed and the necessity of employing different charts for screening, monitoring, diagnostics and expertise is outlined (2 figs, bibliography: 10 refs).

criteria of quality, ETDRS charts, golden standard, methods of measurement, visual acuity