[Comparison of the threshold interpolation and whole-line method on logMAR chart and Snellen chart for visual acuity testing].

The main goal of our study was to prove the statistical significant difference between the threshold interpolation logMAR method on ETDRS chart and the whole-line method on Snellen chart with Sloan letters. We had 108 measurements with the threshold interpolation method and the whole-line method on ETDRS chart and the whole-line method on Snellen chart. The average value measured with the threshold method in ETDRS was 1,132 (min. 0,660, max. 1,580), with the whole-line method on ETDRS it was 1,134 (min. 0,630, max. 1,580) and with the whole-line method on Snellen chart it was 1,183 (min. 0,630, max. 1,600). We have proved statistical significant difference between the threshold interpolation method made on ETDRS chart and the whole-line method made on Snellen chart (p < 0.001). The values measured with the whole-line method on Snellen chart were overvalued. The exact and reliable measuring of visual acuity is an important component of further examinations (e.g. contrast sensitivity, perimetry, tonometry), which enable us to make a correct diagnosis of pathological changes on human eye structures.