Comparison of ETDRS Charts Letter Recognition Difficulty for Russian and English-Speaking Subjects

Chedly Mehdi
Postgraduate¹

Golovchenko A. V.
Postgraduate¹

Siplivy V. I.
MD, PhD, Assistant Professor, Chair for Eye Diseases¹

1 - I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation

Chedly Mehdi e-mail: Chedly.mehdi91@gmail.com.

None declared.

The study had no sponsorship.

We compared the difficulty of letter recognition in ETDRS charts for English-speaking (according to literature) and Russian-speaking (own data) subjects. In both cases, the proportion of incorrect recognitions was calculated for each letter by dividing the total number of times that letter was read incorrectly on discriminant lines by the total number of times that letter appeared on discriminant lines. Comparison of recognition difficulty for each letter was performed by Fisher's exact test. Among the letters, that significantly differ in recognition difficulty and absent in the Russian alphabet, symbol S was recognized better by Russian speakers, and symbol Z was better recognized by native English speakers. At the same time, the symbol H (common to both alphabets) was significantly easier to recognize by English speakers. Obtained results indicate that native language may affect the ability to recognize optotypes. This may present some difficulty in comparing the results of visometry in different populations, even if charts with letters common to different alphabets are used.

visometry, visual acuity, ETDRS tables, complexity of optotypes

10.29234/2308-9113-2022-10-1-11-18

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