28 AMD Facts That May Surprise You
Here are 28 facts about age-related macular degeneration for each day in February to celebrate AMD Awareness Month. Let’s resolve to make AMD knowledge the focus of every month moving forward!
78% of AMD patients have irreversible vision loss by the time they seek treatment
According to recent studies, as many as 78% of patients are first diagnosed with age-related macular degeneration (AMD) having already suffered irreversible vision loss. Nearly half of them are first diagnosed with an acuity of 20/200 or worse.
February was established as AMD Awareness Month in 2008 by Prevent Blindness
Prevent Blindness, the nation’s leading volunteer eye health and safety organization dedicated to fighting blindness and saving sight established AMD Awareness Month. The mission behind this is to disseminate information and promote regular testing. When caught in its initial stages, we’re better able to prevent vision loss that occurs as the disease progresses. Early detection and treatment are critical. Visit Prevent Blindness’s page on AMD here.
Difficulty seeing at night is the first symptom of AMD
Per multiple peer-reviewed articles, loss of photoreceptor cells, particularly rod cells involved in night vision, occurs before structural physiological changes are visible upon examination.
Age-related macular degeneration is the leading cause of adult blindness in the U.S.
A study published in British Journal of Ophthalmology assessing prevalence and causes of blindness and vision impairment in high-income regions in 1990 and 2010 found that macular degeneration has become the most important cause of blindness.
AMD is much more prevalent than glaucoma and dry eye combined
According to the American Academy of Ophthalmology, dry eye affects 4.88 M US adults over age 40 and glaucoma affects 2.7M. Meanwhile, AMD affects 11.2M Americans, making it much more prevalent than dry eye and glaucoma combined.
Smoking is the biggest modifiable risk factor of AMD
Current smokers carry a 2.5 to 4.8 times higher risk than non-smokers for developing AMD. Sadly, less than 50% of smokers know smoking may contribute to blindness caused by AMD.
Delayed dark adaptation indicates subclinical AMD at least three years before it’s clinically evident
The ALSTAR study, published in Ophthalmology, prospectively tracked two cohorts of adults age 60 and older: one having abnormal dark adaptation at baseline and one having clinically normal retinal health at baseline. Three years later, the subjects with abnormal dark adaptation at baseline exhibited clinically detectable AMD at twice the rate of individuals with normal dark adaptation at baseline and had advanced beyond the earliest stages of AMD at eight times the rate. The relationship between dark adaptation impairment and incident AMD was robust and not affected by aging or smoking status. The study demonstrates that dark adaptation impairment indicates subclinical AMD at least three years before it is clinically evident.
Impaired dark adaptation is the earliest biomarker of AMD
Studies show delayed rod-mediated dark adaptation in older adults with normal macular health is associated with incident early AMD three years later, making impaired dark adaptation a functional biomarker for early disease.
AdaptDx Pro measures impaired dark adaptation, the earliest biomarker of AMD, with 90% sensitivity and 90% specificity, making it more accurate than visual field tests.
The AdaptDx Pro is an automated tool that sensitively measures dark adaptation in AMD.
In a pivotal study of dark adaptation conducted at Harvard, Johns Hopkins, and Penn State universities, it was found that the AdaptDx Pro Rapid Test for dark adaptation is a highly accurate measure of impaired dark adaptation and gives a clear, objective measurement of retinal function with 90% sensitivity and 90% specificity for the presence of AMD.
At least 25% of clinical AMD is going undiagnosed in primary eye care today
A landmark study published in JAMA Ophthalmology shows at least 25% of clinical AMD is going undiagnosed in primary eye care today, even with visible clinical signs (drusen).
There is specialized care for patients with AMD
Equipped with the most current knowledge and advanced technology, an AMD Center of Excellence has dedicated staff that receives ongoing training to best serve patients with AMD.
Chronic sunlight exposure increases the risk of incident AMD
Epidemiological evidence suggests that chronic sunlight exposure increases the risk of incident AMD and its progression. Likewise, there may be a potential benefit of protective eyewear.
Rates of AMD are expected to double by 2050
The number of people living with macular degeneration is expected to reach 196 million worldwide by 2020 and increase to 288 million by 2040.
High cholesterol is a risk factor for AMD
Other factors include age, ethnicity, family history, obesity, and smoking.
Before drusen are visible, a thin layer of cholesterol is building up along Bruch’s Membrane for several years, causing oxidative stress and inflammation
Panmacular cholesterol (basal laminar deposits and basal linear deposits) starts to build up along Bruch’s Membrane. While not visible with imaging, this layer of cholesterol deposits affects photoreceptor health, causing oxidative stress and inflammation. In addition, it impairs normal transport, including that of vitamin A, across Bruch’s membrane. In effect, AMD causes a localized deficiency of vitamin A, and dark adaptation is the best test to measure this change. Peaks in these cholesterol deposits eventually become clinically visible drusen.
AMD negatively impacts the U.S. economy by $30 billion annually
AMD is a major public health problem that has a devastating effect on patients and marked adverse financial consequences for the economy. An economic analysis based upon losses to the gross domestic product suggests that AMD has approximately a $30 billion annual negative impact. The return on investment is therefore potentially high for both treatments with current AMD therapies and the research costs invested in the development of new AMD treatment modalities.
As a biomarker of AMD, dark adaptation impairment indicates the disease is already present
Impaired dark adaptation is NOT a risk factor, it is the earliest manifestation of the disease. Genetic testing and macular pigment density (MPOD) can indicate a heightened risk for developing AMD, but neither indicates the actual presence of disease.
Nutraceuticals slow the progression of AMD
Early detection and intervention through regular monitoring, vitamin therapy, and lifestyle changes have shown in practice to slow the progression of AMD.
People who regularly consume a Mediterranean-like diet carry an overall lower risk of developing advanced AMD
Studies suggest that subjects who regularly consume a Mediterranean-like diet carry an overall lower risk of development of advanced AMD as compared to those who regularly consume a traditional Western diet. A recommendation should be made that patients avoid traditionally “Western” dietary pitfalls (high glycemic index foods, high-fat dairy products, fried foods, and processed meats), and instead, follow healthier eating styles like the Mediterranean diet. This diet includes high intake of fruits, legumes, vegetables, nuts, seeds, and other grains; olive oil as the main source of monounsaturated fat; dairy products, fish, poultry, and wine in moderate amounts; and limited intake of red and processed meats.
Exercising regularly and maintaining overall health may prevent or delay the onset or progression of AMD
An active lifestyle has been shown to reduce the risk of progression to CNV. For those who participated in cardiovascular exercise of any intensity three or more times per week, the incidence of CNV was reduced by 33 percent. For those who walked one or more blocks per day, the incidence of CNV was half compared with those who walked less than one block per day.
Systemic disease management may help ward off AMD
Based on epidemiological studies, several systemic conditions carry an increased risk of developing AMD. Keeping cardiovascular disease, diabetes, hypercholesteremia, and obesity in check may help preserve vision in these patients, as well as improve their quality of life.
Age, ethnicity, and gender play a role in the development of AMD
Not only does the risk of AMD increase with age, data suggests ethnicity and gender also influence the likelihood of developing the disease. According to the National Eye Institute, AMD is more prevalent among white Americans as compared to other races. Perhaps partly due to life expectancy discrepancies, 65 percent of AMD cases in the US were women in 2010.
Oxidative damage to the retinal tissue can contribute to both the onset and progression of AMD
The retina becomes more susceptible to oxidative damage as we age, which contributes to age-related retinal cell dysfunction and loss associated with decline in visual function. Current therapeutic strategies are largely focused on increasing antioxidant levels to offset oxidative damage.
AMD disrupts vitamin A absorption in the retina
Cholesterol accumulation, trademark pathophysiological aspect of AMD, causes 3 primary insults to the retina: inflammation, oxidative stress, and disruption of oxygen and nutrition supplied to the outer retina. A consequence being, compromised vitamin A absorption. Resulting vitamin A deficiency impairs dark adaptation, the first functional symptom of AMD.
Wet AMD accounts for approximately 90% of the severe vision loss caused by macular degeneration
Although it affects only 10-15 percent of those who have the condition, wet AMD accounts for approximately 90 percent of the severe vision loss caused by macular degeneration. In this advanced stage, the membrane underlying the retina thickens and breaks, disrupting oxygen supply to the macula. The body tries to compensate by growing new blood vessels, but these are fragile and their malfunction causes permanent damage to the macula.
Approximately 70% of adults over age 50 experience difficulty with night time vision
Anecdotal evidence indicates nearly two-thirds of older adults will report experiencing nighttime difficulties if asked during routine eye care examination.
Although visual acuity becomes impaired as AMD progresses, it is not usually affected in earlier stages of the disease
Changes in visual acuity usually signify that AMD has progressed to intermediate or late stage disease. Because of this, 37% of AMD patients have visual acuity of 20/200 by the time they first seek medical attention.
The AdaptDx Pro is an accurate, advanced tool to help detect AMD at its earliest stages – at the onset of night vision problems, three years before drusen are visible, and before irreversible vision loss occurs
Numerous studies have shown that declining retinal function – specifically the ability to adapt to darkness – is impaired by AMD at least 3 years before it can be seen clinically. AdaptDx Pro detects dark adaptation impairment, a biomarker for AMD, using a proprietary parameter called the Rod Intercept (RI). The AdaptDx Pro technology – supported by more than 20 years of research-validated at major medical centers including Johns Hopkins, Harvard and Penn State – is shown to be 90% sensitivity and 90% specificity for the presence of AMD.