A holistic approach to the aging population’s vision is very critical to achieving an overall wellbeing. Maintaining vision for our geriatric patients extends well beyond continuing their activities of daily living – it’s a component of their very basic health. As a retinal provider in our community, I admit to ample bias in suggesting that visual health is truly integral; despite my confessed partiality, the data does, in fact, support this! Our aging patients with severe vision loss significantly increases the risk of falls and fractures, in turn increasing their likelihood of hospital or nursing home admissions or becoming disabled. Challenges with other very basic things that are critical to daily health can become challenging with even moderate visual impairment, including accurately identifying medications, difficulty with bathing, dressing, or safely mobilizing around typically familiar areas like one’s house or the local grocery store. After considering these challenges it becomes very easy to see why there is a significant increase in the risk of depression associated with visual impairment with aging.
When we consider caring for geriatric patients with vision problems, age-related macular degeneration (AMD) is by far the most prevalent and easily the greatest threat to these patients. AMD affects over 10 million people in the United States alone and with the aging of the US population, this number is expected to increase significantly in years ahead. Establishing a basic familiarity with this condition will enable all of us to be more alert for these symptoms and more prepared to protect our patients.
AMD deteriorates the macula, which is located centrally in the retina and responsible for our central vision and focusing on fine detail. The visual decline corresponds to the stages of dry AMD that often progress slowly but can convert unpredictably to the potentially more devastating wet AMD.
Early dry AMD, characterized by small drusen which are small yellow deposits made of lipids, patients may experience slight blurry vision centrally, or metamorphopsia – noticing small wavy lines when trying to focus on a straight line. In intermediate dry AMD, these symptoms become more pronounced, with many patients experiencing significant fatigue with reading, often starting to close one eye due to a slight asymmetry of disease. In advanced AMD, patients develop atrophy typically in the areas where they initially developed drusen. Histologically this corresponds to cell death underneath the drusen, and functionally this translates to gaps in their vision. In the earliest stages of atrophy, patients experience loss of contrast, increased glare, and often describe skipping letters when reading. In the most advanced stage, atrophy becomes confluent throughout the central macula, described as geographic atrophy, and patients can become legally blind and lose the ability to recognize faces.
The typical progression through the stages of dry AMD is slow and occurs over several years to even decades. However, approximately 10-15% of patients with dry AMD can convert to the wet form of AMD, where a new vessel forms right in the center of one’s vision and can lead to severe vision loss literally overnight or over the course of weeks. Our best understanding from research supports that chronic oxidative stress in this aging macula creates a feedback demand for more oxygen, which engenders this harmful vessel to recruit more oxygen. Rather than recruiting any oxygen, this new vessel just bleeds and starts making a blind spot right in the central visual field. Fortunately, we have developed great treatments in the form of intravitreal injections of anti-VEGF for the wet form of macular degeneration. These treatments play superb defense – with over 95% of patients avoiding further severe vision loss after commencing timely treatment. These treatments also are playing better and better offense, with approximately half of patients now enjoying a significant improvement in vision after converting to the wet form of AMD.
In summary, we all need to work together as a team to protect our aging patients. Understanding the most important threat to our geriatric patients’ vision will enable us all to play a greater role in defending against severe vision loss, and deterring all the associated harmful aspects that accompany vision loss. As always, we remain committed to our mission of saving sight and enhancing lives and invite your teamwork in joining this important cause.