Abstract
Abstract: :
Purpose: Much of the reading rehabilitation in patients with low vision has focused on providing magnification aids and training patients to be aware of the location of their preferred retinal locus (PRL). These training curricula have concentrated on letter identification and reading practice using the eccentric location. There has been little experimental work on training the basic eye movement skills involved in reading. In this study, we designed a program that emphasizes eye movement training and secondarily trains cognitive function based on information derived from the peripheral retina. Methods: We trained eye movements in 11 patients with AMD (age range 46 to 82 years) in eight 2–hour sessions. The patients’ visual acuities ranged from 0.48 to 1.3 logMAR. We trained reading eye movements by beginning with small horizontal saccades to cognitively easy stimuli and then progressed to larger eye movements in response to pairs of letters, words, and sentence targets. The font size used for training was 0.5 log units above the letter acuity threshold for the subject's PRL. Throughout the training session, the subject's pupil was monitored using a camera and recording system. Immediate feedback was given about the direction and appropriateness of saccades. Results: We measured the reading speed for sentences (adapted from the Woodcock Johnson III Tests of Achievement, Reading Fluency Test) presented on a computer monitor. The reading speed versus character font size data were fit with a sigmoid equation: y = a/1 + exp (–(x – b)/c), where a quantifies the horizontal position of the curve, b is the maximum reading speed, and c is the slope of the function. The differences in these parameters pre– and post–training were calculated. After training, the maximum reading speed increased and the size of the font that the subjects could read decreased for 10 of the 11 patients. The increase in speed and decrease in size were statistically significant (t = –2.3, P = 0.045 and t = 5.4, P < 0.001, respectively). Conclusions: Our results suggest that eye movement training can improve reading speed in patients with AMD.
Keywords: low vision • age–related macular degeneration • reading