As we reviewed Margaret’s ultra-widefield retinal images with her, we pointed out the small yellow deposits in her macula. She breathed in sharply, and her hand covered her mouth when we said that these were, “early signs of age-related macular degeneration (AMD).” Margaret asked me what could be done to prevent it. Her history revealed both her father and uncle had suffered from AMD; she didn’t want it to happen to her.
All of us have had similar discussions with patients. As the population continues to age, more people will be at risk for developing AMD, requiring us to have even more conversations with patients.
Here, we provide a primer on AMD and a discussion of our crucial role in the care of these patients.
According to a recent study by researchers at the University of Wisconsin School of Medicine and Public Health and the CDC, approximately 6.5% of Americans age 40 and older have some degree of AMD. Most experts suggest that non-exudative (dry) AMD (explained below) accounts for about 80% to 90% of diagnosed cases, with conversion to exudative (wet) AMD (also explained below) at about 10% to 15%. Age is the major factor in raising this conversion percentage, but diabetes is also a critical factor.
The primary risk factor for developing AMD is aging. In fact, the condition is the leading cause of severe vision loss in people older than age 50. Genetics also play a large role in predicting risk. Caucasians are more at risk for developing AMD than any other race. Other risk factors include smoking and sedentary life with a poor diet.
AMD is a progressive blinding disease, which has two primary presentations: The non-exudative type and the exudative type. Even though fewer people have the exudative type, it accounts for 90% of the cases of legal blindness due to AMD.
The non-exudative type appears as amyloid deposits (drusen) in the macula. The larger and more prevalent the drusen, the greater the risk of vision loss: The macula deteriorates, and the retinal pigmented epithelium breaks down. This process leads to loss of central vision and decreased VA. Usually this process takes several years, with the end stage, geographic atrophy, resulting in severe vision loss. Thus, non-exudative AMD may convert to exudative, as the disease progresses.
Identifying early AMD changes has become easier with advanced OCT and auto-fluorescence in-strumentation. These technologies, along with new research and education in school and CE have allowed O.D.s to identify AMD risk earlier. Combined with genetic testing for AMD risk, O.D.s have a plethora of tools to help educate and counsel patients on risk mitigation and early intervention. In addition, O.D.s can better diagnose conversion to exudative AMD, allowing retinal specialists to preserve more vision in the affected eye and, perhaps, keep the vision in the other eye from deteriorating.
Non-exudative AMD treatments are comprised of dietary supplements, which may contain antioxidants, zinc, lutein, zeaxanthin and mesozeaxanthin. Lifestyle modifications, such as not smoking, eating a healthy diet and exercising regularly, have been shown to decrease the incidence of AMD. In addition, several in-vestigational treatments, such as micro-current stimulation and eye drops that reduce the retinal amyloid deposits, hold future promise for these patients.
Exudative AMD appears as choroidal neovascularization. These choroidal vessels may leak either serous fluid or blood into the sub-retinal space, which causes separation of the retinal layers. This results in distortion of central vision and potential death of the macular cells with associated vision loss. Patients may wake with distorted vision if the fluid leak occurred while they were sleeping.
Exudative AMD treatments are comprised of anti-VEGF injection options and laser photocoagulation, provided by our ophthalmology colleagues.
As the primary care providers of ocular health, we see the vast majority of patients entering the early and intermediate stages of AMD. As early intervention can delay the onset and slow the progression of this dreaded disease, we owe it to our patients, and ourselves, to become actively involved in the care of AMD patients. How can we, as optometrists, be prepared to help patients like Margaret?
First, we must be able to accurately diagnose AMD. The sooner we do this and treatment is implemented, the better the outcome. An array of diagnostic devices are available to aid us in this endeavor, with patient buy-in to prescribed management achieved via patient education regarding the purpose and findings of each device. In “Explain Diagnostic Devices,” p.21, Laurie Sorrenson, O.D., F.A.A.O., tackles this.
Additionally, we must prescribe dietary supplements, where needed, to enable patients at risk and who have AMD to maintain their vision. One way to increase the likelihood of patient compliance is to offer the supplements we believe in, in our practices. Harvey P. Hanlen, O.D., F.A.A.O., discusses this in “Support Eye Health,” p.25.
Also, Kenneth Lawson, O.D., describes how to best bring these facets of care all together with “The AMD Experience,” p.28.
MAKE IT HAPPEN
Patients who can avoid severe vision loss from AMD can maintain their independence, travel, enjoy all the visual stimuli that our world offers, see their grandchildren grow up; in short, have a higher quality of life. This has certainly been the case with Margaret. We urge you to take the opportunities in the articles that follow in this issue to help your patients and help your practice. OM