Reading performance in unilateral age‐related macular degeneration

Abstract

Purpose: To compare reading performance as mediated by the healthy eye and the affected eye of individuals with recent onset, unilateral, exudative age‐related macular degeneration.Methods: The reading performance of eight subjects (76.3 ± 5.3 years) was assessed under monocular viewing conditions with the affected and the healthy eye. Eye movements were recorded using a spectacle‐mounted, infrared limbal reflection system whilst the subjects read short stories (65 words) printed in 16 point Times Roman font at a working distance of 25 cm. Comprehension was assessed by ‘free’ recall at the end of each story.Results: Acuity in the affected eyes ranged from 0.40 to 0.80 (log MAR) and in the healthy eyes from 0.00 to 0.20. When using the affected eye, reading speed was reduced by 50%, compared to reading with the healthy eye, though comprehension scores were similar. There was also a significant increase (P < 0.01) in the durations of fixation pauses, the time between the initiation of the return sweep and the first forward saccade on the subsequent line and the numbers of regressive saccades, with each forward saccade covering fewer letters. Fixation durations were positively correlated with the mean depth of the field defect.Conclusions: The results seem to indicate that although the motor aspects of reading are affected in the initial stages of the visual loss, comprehension is relatively unaffected for short, simple passages of text.