Low Vision Study Comparing EV Training vs. CCTV for AMD Rehabilitation (AMD)
|AMD||Behavioral: eccentric viewing (EV) training Device: Closed circuit television (CCTV)||Phase 2|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Supportive Care
|Official Title:||A Randomized Controlled Trial of Eccentric Viewing Training vs. Closed Circuit Television Use for Visual Rehabilitation From Age-Related Macular Degeneration|
- The primary outcome measures reading speed for 1.3M print (in correct words per minute). [ Time Frame: 6 weeks intervention ]
- The secondary outcomes measures 1. Reading accuracy for 1.3M; [ Time Frame: 6 weeks intervention ]
- 2. Reading speed and accuracy for 1M [ Time Frame: 6 weeks intervention ]
- 3. Reading performance tests. [ Time Frame: 6 week's intervention ]
- 4. Reading Behavior Inventory [ Time Frame: 6 week's intervention ]
- 5. VFQ-25 plus 2 extra questions). [ Time Frame: 6 week's intervention ]
- 6. Geriatric depression scale [ Time Frame: 6 week ]
|Study Start Date:||September 2009|
|Study Completion Date:||September 2011|
|Primary Completion Date:||September 2011 (Final data collection date for primary outcome measure)|
Experimental: Eccentric viewing
Eccentric viewing is the use of a retinal locus other than the anatomical fovea for fixation in cases when there is central vision loss. This other area (or areas) is called the preferred retinal locus (PRL). In eccentric viewing the patient is aware that they are "looking to the side" or "using their side vision". Most patients with a dense central scotoma will develop eccentric viewing naturally over time. It is thought, however, that, in many cases the naturally developed PRL is not in the ideal position. The four components of eccentric viewing that will be taught are: 1) The optimal direction for eccentric viewing 2) Using large objects to teach eccentric viewing 3) Repetitive practicing of the technique and 4) Maintaining the eye in the eccentric viewing position.
Behavioral: eccentric viewing (EV) training
Eccentric viewing training for 6 weeks, minimum two 10 minutes per day.
Other Name: eccentric fixation training, vision training
Active Comparator: CCTV arm
A CCTV is an electro-optical device mainly used for reading, but which can also be used for writing or viewing pictures. It is comprised of a video camera which faces downwards towards the reading material and which inputs the image to a digital monitor. Magnification is variable over a large range. By means of a zoom lens and the brightness, contrast, and image polarity (black letters on white or white on black) can be controlled to provide the best combination of viewing conditions for an individual user. The significant advantages of CCTV over optical magnifiers are that it provides high levels of magnification with a greater field of view (compared to the equivalent optical device), allows reading at a more normal viewing distance of about 40 - 50 cms and allows binocular viewing.
Device: Closed circuit television (CCTV)
A CCTV is an electro-optical device mainly used for reading.
Other Name: EVES, electronic vision enhancement system
Age-related macular degeneration is the single most common cause of visual impairment in Canada, affecting people over the age of 55 years. It causes loss of central, detailed vision, resulting in difficulty with fine vision tasks, such as reading and writing. At present there is no fully effective prevention or treatment for this condition, but people do benefit from visual rehabilitation. Two of the most common rehabilitation techniques are eccentric viewing training and an electronic magnification system called a Closed circuit television (CCTV). In eccentric viewing training the person is taught to use his or her remaining side vision, instead of central vision. The CCTV provides high levels of magnification to compensate for the loss of detail vision. The purpose of this randomized clinical trial is to compare the effectiveness of these two interventions. In the study people will be randomly assigned to either receiving eccentric viewing training or a CCTV. This will happen after they have received basic, optical low vision services and training through the CNIB. We will assess their performance with either the CCTV or EV training with a variety of reading tasks and questionnaires. The results will give evidence for how it is most beneficial to use resources and as such will be very important in future planning of low vision services.
Hypothesis: Eccentric Viewing Training will improve reading speed over CCTV by at least 10 words per minute in patients with advanced AMD.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00971464
|CNIB, Toronto Branch|
|Toronto, Ontario, Canada, M4G 3E8|
|Principal Investigator:||William Hodge, MD, PhD||University of Western Ontario, Canada|