Federal Funding and Research are Key to Addressing Age-Related Macular Degeneration
February is AMD/Low Vision Awareness Month. Join the conversation on social media by sharing this blog post on Facebook and Twitter using the hashtags #AMDAwarenessMonth and #LowVisionMonth.
Age-related macular degeneration (AMD) is the leading cause of vision loss among people aged 50 and older in developed countries. In the United States alone, the number of people with advanced AMD, is over 2 million. This number is expected to increase to 5.4 million by 2050. There is currently no cure for AMD, making it a major public health crisis. As with many kinds of vision loss, especially those involving the central visual field, it is easy to think of the disorder as a loss of acuity – reading becomes difficult, small objects are hard to distinguish, and faces can be a blur. However, AMD also affects most other facets of daily life.
At The Smith-Kettlewell Eye Research Institute, scientists are examining the disease at multiple stages and in the context of multiple aspects of daily living, with funding from the National Institutes of Health. In early stages of the disease, there may be no detectable decrease in visual acuity.
However, studies show that other aspects of vision function are affected, often prior to reduced acuity. One study is assessing a battery of non-standard vision functions in people with early to intermediate AMD, but no standard acuity loss, to determine if any of these measures are predictive of progression to advanced AMD. This longitudinal study could help identify individuals who should be monitored most closely following an early AMD diagnosis.
In other studies, scientists are working to help individuals in later stages of AMD utilize their residual vision. When information from part of the scene is missing due to vision loss, it can be difficult to find everyday objects, such as the correct box of cereal on a store shelf. Training individuals to look in regions that were previously within the blind region can eliminate the frustration of searching repeatedly.
When the pattern of vision loss is not the same in the two eyes, it can impair depth perception, which may impact performance in daily manual tasks. Research has shown that the ability to discriminate differences in depth is related to the ability to manipulate objects. Follow-up studies are underway to determine whether alternate strategies can restore coarse depth perception in individuals with AMD.
The perception of motion due to object or self motion, is another important aspect of visual function. Research into navigation, stability and balance has the potential to improve the safety, activity involvement and engagement of the AMD community. Studies on how individuals with AMD view moving objects with peripheral vision are shedding light on deficits in visual function. Additionally, research indicates that motion direction with respect to the region of visual damage must be considered in any training regimen.
The Smith-Kettlewell Eye Research Institute is a non-profit organization focusing on basic, clinical and rehabilitation research. A unique aspect of AMD research at the Institute is the emphasis on creating training and rehabilitation tools that are accessible, engaging and can be translated to daily life. For more information, visit: www.ski.org.
Click here to read the National Eye Institute’s AMD fact sheet.
Preeti Verghese, Ph.D., is a Senior Scientist at The Smith-Kettlewell Eye Research Institute, Lori A. Lott, Ph.D., is an Associate Scientist at the Institute, and Natela Shanidze, Ph.D., is a Postdoctoral Fellow at the Institute.