Macular Disease Rehabilitation Improves Visual Reading Ability

By Charles Bankhead
HINES, Ill., 14 may 2008-- Low-vision troubles for patients with macular disease can be eased significantly by a 10-hour multifaceted rehabilitation program, found a study here.
In a four-month controlled randomized trial of the low-vision rehab, every vision-related endpoint improved significantly, Joan A. Stelmack, O.D., of the Hines VA Hospital, and colleagues reported in the May issue of Archives of Ophthalmology.
Participants were randomized to a four-month waitlist or immediate treatment. Because those in the waitlisted control group had vision deterioration during the four months, low-vision rehabilitation should be offered as soon as possible, the authors concluded.
"Based on the large effect sizes observed for a variety of functional domains, [we] conclude that at least 10 hours of outpatient low-vision therapy, including a home visit, is justified for patients moderately and severely impaired by low vision," Dr. Stelmack and colleagues said.
Low vision that limits daily function is one of the top 10 causes of disability. Most cases of low vision are caused by age-related macular diseases, which are treatable, the authors noted, though not curable.
In contrast to private clinics, where trials of low-vision rehabilitation has resulted in only modest overall improvement at best in clinical trials, the multidisciplinary VA study showed almost a seven-fold greater effect size, the authors said.
The VA Low Vision Intervention Trial (LOVIT) involved 126 patients with low vision, defined as worse than 20/100 but better than 20/500 in the better eye.
The patients, whose mean age was almost 80, were randomized to five weekly sessions at low-vision clinics to learn strategies for effective use of remaining vision and how to use assistive devices.
Each patient in the treatment group was assigned five hours of homework between sessions to practice use of assistive devices to perform routine daily activities. Examples of the devices included reading glasses, a monocular telescope, pocket magnifiers, and filters for glare control. Each patient also had one home visit for instruction in use of the assistive devices and environmental adaptation.
The primary outcome was the change in reading ability at four months compared with baseline. Reading ability was assessed by the 48-item VA Low-Vision Visual Function Questionnaire-48 (LV VFQ-48) instrument, which covers four vision-related functional domains: reading, mobility, information processing, and motor behavior. Secondary outcomes were changes in the other three domains of the LV VFQ-48.
The investigators considered an improvement of 0.78 logit (equivalent to 31%) in visual reading ability for the treatment group compared with the control group as the threshold for statistical significance.
For the primary outcome of visual reading ability, the treatment group had 2.06-logit mean improvement versus a 0.37-logit loss in the control group, resulting in an overall difference of 2.43 logits (P<0.001). All secondary outcomes also improved significantly (P<0.001) in the treatment group versus the control group:
Visual mobility, 0.84
Visual information processing, 1.38
Visual motor skills, 1.51
Overall visual function, 1.63
For each outcome, the treatment group demonstrated improvement and the control group had vision loss.
The authors had no financial disclosures.

Primary source: Archives of OphthalmologySource reference:Stelmack JA, et al "Outcomes of the Veterans Affairs Low Vision Intervention Trial (LOVIT)" Arch Ophthalmol 2008; 126: 608-617.