The purpose of this study is to measure the effectiveness of a newly-designed oculomotor training program for patients with macular disease, including age-related macular degeneration.
Age-related macular degeneration (AMD) is currently among the top three leading causes of central vision loss in veterans (Chomsky et al., 1995) and is the most prevalent cause of blindness among veterans (37.2%, Quillen \& Henry, 2000). The loss of central vision associated with these diseases has a profound impact on the quality of life to those affected, with many suffering depression. It is devastating to no longer be able to read a newspaper or recognize facial expressions. The use of preferred retinal locations (PRLs) to compensate for diseased foveae has offered hope to these patients in regaining some function. The investigators have developed a protocol that includes training in two major visual skills areas: * Visual awareness and eccentric viewing; and * Reading practice with sequentially lexical information Module 1 focuses on making the patient aware of better vision at an eccentric location relative to degraded vision at the diseased fovea. Module 2 is focused on reading practice without eye movements. These program curriculums and preliminary results are provided in the present proposal. The primary aim of this proposal is to quantitatively assess the relative effectiveness for improving reading and to establish the minimum training time need for skill improvement. One hundred and twenty patients with macular disease who are already using a PRL and similar in visual characteristics (e.g., visual acuity, contrast sensitivity, size of scotoma, duration of the disease) will be included the study. All patients will be trained with both modules using a repeated measures-completely counterbalanced - design to control for training order effects. In addition, all patients will be assessed using the same outcome measures of reading (using MNRead Acuity Charts and the View Sentences Test). The performance of the patients on the outcomes battery post-training will be compared to their pre-training performance on the same battery. Questionnaires (the Veterans Administration Low Vision Visual Functioning Questionnaire, CES-D, Short Form-36, and Adaptation to Vision Loss Scale) will also be administered to assess perceived abilities to perform everyday tasks, adaptation to vision loss, moods, and general health. In addition, patients will also be assessed on the exercises practiced during the module at the end of each daily training session to determine exactly when in the training protocol an improvement in performance on the exercises being trained has occurred. These daily performance measures provide for a finer scale for detecting performance changes. Statistical analyses will be conducted to answer the following questions: * Does a combination of eccentric viewing awareness and oculomotor training produce significant improvements in reading rate? * Which exercises are most effective in training the visual skills associated with reading and at what point during the course of training do the patients reach asymptotic performance? * How do co-factors such as age, PRL size and location, and cognitive capabilities relate to training outcomes? Advancements are being made in the area of retinal cell transplantation, gene therapy, and retinal prosthetics. When these techniques become part of the standard clinical care, it is likely that all the patients will require vision rehabilitation techniques to help them make sense of their potentially fragmented percepts. This research offers an evaluation of relative successes of the components of reading rehabilitation and will lead to the design of an efficient and effective composite training strategy.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Masking
SINGLE
Enrollment
36
In this module, awareness of the PRL location and eccentric viewing were trained. Exercises based on published sources were administered. One example of these exercises is the clock face display adapted from Holcomb and Goodrich and Maplesden. This module also focused on awareness of the perceptual consequences of using a PRL. The purpose of these training exercises was to allow the subjects to appreciate perceptual alterations that occur when using a PRL and to practice making perceptual discriminations with the peripheral retina. Previously published work has demonstrated that perception in the peripheral retina can be affected by practice.
In this module, control of eye movements was trained. These exercises began with a series of saccade tasks to nonalphabetical stimuli and then progressed to single letter, letter pairs, and word stimuli. Subjects were instructed to make a saccade between the dots. The experimenter provided feedback concerning the appropriateness of the saccades, and the alternation rate of the dots was increased as performance improved.
Jesse Brown VAMC (WestSide Division)
Chicago, Illinois, United States
Sentence Reading
To assess reading performance, after each training module (1-3), two lines of text were presented at the center of the monitor. Each subject was seated with his or her forehead on a head rest at a viewing distance of 40cm. The subject read each sentence aloud and indicated whether it made sense by responding true or false. Reading speed was calculated using an algorithm similar to that used for the MNRead test. The number of words read correctly was divided by the time required to read the sentence to yield a measure of reading speed in words per minute (wpm). Sentences were displayed at sizes of 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 log units above the subject's letter acuity threshold. Five sentences were presented at each font size. We used 105 different sentences so that no sentence was repeated for any subject. Average speed of reading (log wpm) was plotted as a function of font size (logMAR).
Time frame: Pre-training, 6 weeks, 12 weeks, 18 weeks
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
In module 3, we wanted to assess only the higher-level effects of reading practice. Subjects practiced reading using stimuli that did not require reading eye movements. An example is short sentences that were presented one word at a time at a single location on a screen (Rapid Serial Visual Presentation \[RSVP\]). At the end of the sentence, subjects reported whether the sentence made sense or not. We also had our subjects practice reading scrolled text. Although, eye movements and saccades may spontaneously occur under the text presentation conditions of this module, they are not the efficient saccades necessary for reading.