Reading Random Word Sequences (The SKread Test)

This vision test shows random word sequences that prevent the prediction of upcoming words by linguistic criteria and is simple to score in a clinical setting.

It combines the standardized format of the MNread test with sequences of random words and letters, like in the Pepper test. We have used this test on hundreds of patients with maculopathies and on healthy subjects to measure their reading speed and register errors.

Reading speed was always higher for continuous text than for random word sequences, even in normally sighted subjects. The number of errors made was always higher than for reading continuous text. The type of errors made by patients with a central Scotoma depended on the relative position of the Scotoma to the retinal location used for fixation. Patients with a dense scotoma right of fixation made more “right errors” by missing letters at the end of words, while those with a scotoma left of fixation made more “left errors” by missing letters at the beginning of words.

What have we learned? The unpredictability of random word and letter sequences renders reading performance highly dependent on eyesight and less dependent on reading skill and educational level. Recurrent right or left errors can indicate the presence and location of a scotoma without expensive equipment. This knowledge can be used to teach patients about how the scotoma can interfere with their vision.

Reference

MacKeben M, Nair U, Walker L, Fletcher DC. (2015) Random word recognition chart helps scotoma assessment in low vision. Optom & Vis Sci, April, Vol. 92, No. 4, 421-428