Report

Student creates and commercialises first standardised Arabic reading acuity chart

In an effort to eliminate the potential for inconsistent eye test results and improve eyecare for millions of Arabic speakers, Dr Balsam Alabdulkader created the chart after returning to her clinical job in Riyadh, Saudi Arabia, where she realised the limitations with current testing regimes.“For my masters thesis project, I worked on the gold standard chart in English and learned about the importance of the standardised features in near acuity charts. I wanted to get a standardised chart in Arabic for my testing patients. I then discovered that we don’t have one.” Alabdulkader, a PhD student at the university’s School of Optometry & Vision Science, said.According to Dr Susan Leat, who supervised the project, there were no standard texts in Arabic from which to draw sentences and no standard or accepted font in the language.“Nor is there any standard method of determining the size of Arabic text, as there is in languages, such as English, that use Roman letters,” she said.In the development of reading acuity charts, sentences are selected and tested for grade level, reading speed and other factors. The sentences are then arranged in a standard format, with sentences that gradually become smaller in a logarithmic scale, as the patient reads down the chart.To determine font size, chart designers use the x-height: the distance between the baseline and the top of lower-case letters. This syst was effective for Roman letters, however, Arabic is cursive and there is a wide variation in letter height.To overcome this, Alabdulkader and Leat used a single repeated sentence, and picked one letter to use as a “yardstick” to determine the font size for each line and the spacing between the lines.As there is no way to physically compare the Arabic print size to Roman letters, the researchers pirically scaled the Arabic print against English using the reading performance of participants who could read both languages.The resulting BAL (Balsam Alabdulkader- Leat) chart is available in three different versions. Each chart has fifteen print size levels that are labelled in logMAR and point size.The two researchers have obtained copyright on the BAL chart and have now commercialised it through Precision Vision.