Treat AMD at first detection
Small changes can make a big difference, one clinician says.
When do you initiate treatment for age-related macular degeneration? Do you wait until you are 100% certain that the patient has intermediate stage disease before you suggest supplements or lifestyle changes? Or do you try to treat AMD before it progresses to the intermediate stage? And what about the patient’s role in decision-making? Should he or she be given an opportunity to decide how proactive intervention should be?
Some doctors may say there are no right or wrong answers to these questions. However, the data suggest we may be making poor use of proven methods to avoid or delay vision loss. Why? For me and for many of my colleagues, it had a lot to do with the overly complex manner in which basic standards are traditionally taught. However, this should not stand in our way of making what would otherwise be simple, evidence-based decisions.
Treating AMD before it is too late is not complicated at all. In fact, when you start experiencing the impact this has on the lives of patients, their families and your practice, you will wonder why everyone is not doing it.
We are failing
If there were ever any doubt that we are not doing enough for our AMD patients, a recent study published in JAMA Ophthalmology put those illusions to rest (Neely et al.). This cross-sectional study, which included 1,288 eyes (644 adults) from patients enrolled in the Alabama Study on Early Age-Related Macular Degeneration (ALSTAR) (Owsley et al., 2014, and Owsley et al., 2016), revealed that doctors are missing AMD about 25% of the time. Also quite concerning is the fact that 30% of the undiagnosed eyes in the study had large drusen, a known risk factor for wet AMD (Neely et al.).
If we are going to start treating AMD more effectively, first we have to learn to diagnose it sooner. In fact, the authors of the JAMA study point out that improved AMD detection strategies may be needed because many of the patients with missed diagnoses would have been candidates for therapeutic intervention with nutritional supplements.
Nonexudative AMD is often not diagnosed until the patient presents with drusen and visual acuity loss. By this criterion, the patient likely has had the disease for years. The patient has lost some of the potential benefits of treatment and is at higher risk of central visual loss, especially in the first eye that progresses to choroidal neovascularization (CNV). There is no cure for AMD, so we must try harder to halt or slow the disease progression. Earlier detection allows earlier treatment, which leads to better patient outcomes. With proper care, significant visual acuity loss may be prevented in many patients.
Currently, as many as 78% of patients are first diagnosed with AMD having already suffered irreversible vision loss, and nearly half of them are first diagnosed with an acuity of 20/200 or worse (Olsen et al., Cervantes-Castañeda et al.).
A better plan
Based upon our current understanding of AMD pathogenesis, the stages of subclinical, early and intermediate AMD all represent different clinical manifestations of the same underlying disease process. As such, the treatment of the disease should be initiated at first detection, regardless of stage. The following treatment recommendations should, therefore, be offered to patients with all stages of AMD.
Quit smoking. Encouraging smoking cessation is the best method to reduce risk of central vision loss. In fact, smoking is the largest modifiable risk factor for the progression of both CNV and geographic atrophy. Current smokers carry a 2.5 to 4.8 times higher risk than nonsmokers for late AMD (Chakravarthy et al.).
Initiate supplementation. Evidence strongly suggests that patients should be prescribed nutritional supplements because, on average, treated patients have better outcomes than untreated patients (Hobbs et al., Carneiro et al.). There are three primary options for the selection of an appropriate nutritional supplement. The first option is to prescribe a macular pigment supplement (the xanthophylls: lutein, zeaxanthin, mesozeaxanthin). The second option is to prescribe a supplement containing both xanthophylls and antioxidants, including zinc and vitamins E and C (eg, an AREDS2 supplement). The third option is to prescribe a xanthophyll supplement to patients with subclinical and early AMD and a xanthophyll-antioxidant combination supplement to patients with intermediate AMD or patients that progress to intermediate AMD.
Make necessary lifestyle modifications. Following a healthy diet, exercising regularly and maintaining overall health may prevent or delay onset or progression of AMD. One study found that women who followed a healthy diet, engaged in physical exercise and avoided smoking had substantially lower risk of early AMD compared with women who did not follow these healthy lifestyles (Mares et al.). Specifically with regard to exercise, an active lifestyle has been shown to reduce the risk of progression to CNV (Seddon et al., Williams et al.). With regard to diet, epidemiological studies have found substantial benefit from higher dietary intake of essential fatty acid-rich foods, especially DHA, found in many species of fish (Querques et al.). Studies also 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 traditionally Western diet (Merle et al.). In our practice, we discuss diet, BMI and supplementation with high quality, highly bioavailable omega-fatty acid products and macular pigment supplements.
Manage systemic disease. As you know, several systemic conditions carry an increased risk of development of AMD. For example, cardiovascular disease, diabetes, hypocholesteremia and obesity have all been associated with increased risk of AMD or progression of AMD (Seddon et al., Sun et al.). Body mass index and abdominal obesity are also independent risk factors for progression to advanced AMD (Seddon et al.). Explain the connection between risk of vision loss and any comorbid systemic diseases, as this may enhance patient adherence to your prescribed care regimens.
Consider retinal light protection options. Epidemiological evidence suggests that chronic sunlight exposure increases the risk of incident AMD and its progression (Sui et al.). Prescribe full-spectrum UV protection for patients and consider high energy visible light (HEVL) blocking (sometimes referred to as blue light-blocking) eyeglass lenses. HEVL IOLs have been widely implanted during cataract surgery for more than a decade. One study found reduced progression of geographic atrophy in patients who had blue-blocking IOLs (Pipis et al.). Likewise, there may be a potential benefit of protective eye wear, which has a few advantages over blue-blocking IOLs. First, the amount of tint can be made task-appropriate (eg, a darker tint for driving) and, second, eye wear is removable should the patient choose to discontinue use.
AMD is a devastating disease that has been complicated by diagnostic and treatment uncertainty for far too long. It is time for optometry to step up and more aggressively address the disease for the good of our patients. Small changes can make a big difference.
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- For more information:
- Laurie Sorrenson, OD, FAAO, opened Lakeline Vision Source in 1995 and is a part-time faculty member at the University of Houston College of Optometry, where she teaches practice management to fourth-year optometry students. She can be reached at email@example.com.
Disclosure: Sorrenson reports she is a consultant for Maculogix.