Training to improve reading speed in patients with juvenile macular dystrophy: a randomized study comparing two training methods

Purpose: In this study, we examined the clinical application of two training methods for optimizing reading ability in patients with juvenile macular dystrophy with established eccentric preferred retinal locus and optimal use of low-vision aids. Method: This randomized study included 36 patients with juvenile macular dystrophy (35 with Stargardt's disease and one with Best's disease). All patients have been using individually optimized low-vision aids. After careful ophthalmological examination, patients were randomized into two groups: Group 1: Training to read during rapid serial visual presentation (RSVP) with elimination of eye movements as far as possible (n = 20); Group 2: Training to optimize reading eye movements (SM, sensomotoric training) (n = 16). Only patients with magnification requirement up to sixfold were included in the study. Training was performed for 4 weeks with an intensity of 1/2 hr per day and 5 days a week. Reading speed during page reading was measured before and after training. Eye movements during silent reading were recorded before and after training using a video eye tracker in 11 patients (five patients of SM and six of RSVP training group) and using an infrared reflection system in five patients (three patients from the SM and two patients of RSVP training group). Results: Age, visual acuity and magnification requirement did not differ significantly between the two groups. The median reading speed was 83 words per minute (wpm) (interquartile range 74-105 wpm) in the RSVP training group and 102 (interquartile range 63-126 wpm) in the SM group before training and increased significantly to 104 (interquartile range 81-124 wpm) and 122, respectively (interquartile range 102-137 wpm; p = 0.01 and 0.006) after training, i.e. patients with RSVP training increased their reading speed by a median of 21 wpm, while it was 20 wpm in the SM group. There were individual patients, who benefited strongly from the training. Eye movement recordings before and after training showed that in the RSVP group, increasing reading speed correlated with decreasing fixation duration (r = -0.75, p = 0.03), whereas in the SM group, increasing reading speed correlated with a decreasing number of forward saccades (r = -0.9, p = 0.01). Conclusion: Although the median effect of both training methods was limited, individual patients benefited well. Our results may indicate a difference in the training effect between both methods on the reading strategy: the RSVP method reduces fixation duration, the SM method decreases the number of forward saccades. Patients can apply their newly learned reading strategy in the natural reading situation, e. g. in page reading without special presentation of the text. These results can be used as a basis for further improvement in training methods for optimizing reading performance in patients with a central scotoma.