Faculty Peer Reviewed
When patients bring up questions or concerns about their vision in the primary care setting, many providers feel ill equipped to handle them. While certain issues are better left for the ophthalmologists, primary care providers can offer patients basic information on how to protect their vision.
The first thing physicians can do is to refer their patients for comprehensive screening eye exams. Certain eye diseases with potentially therapeutic interventions may begin asymptomatically. The availability of pressure-lowering drops for glaucoma, and anti-vascular endothelial growth factor (VEGF) injections for macular degeneration, should impel primary care physicians to encourage screening exams. The American Academy of Ophthalmology recommends that all asymptomatic adults without risk factors for eye disease receive baseline eye exams at age 40. Subsequent eye exams should occur every 2-4 years for adults ages 40-54, every 1-3 years for adults ages 55-64, and every 1-2 years for adults ages 65 or older. Patients with established eye disease should follow their ophthalmologists’ recommendations for frequency of follow-up.
With the increasing comfort and convenience of contact lenses, more and more patients are ditching their glasses. Several types of contact lenses are available with different lengths of wear. Patients may continue to wear their contacts long after they should be thrown away, or wear their “extended wear” lenses overnight. These behaviors can predispose to corneal anoxia and put patients at a significantly greater risk for developing vision-threatening microbial keratitis. Vision loss can be permanent and thus patients should be counseled on proper lens wear and hygiene.
Age-related macular degeneration (ARMD) is the most common cause of visual loss in the United States in the elderly population. Most aging patients have seen a friend or family member lose their vision to this disease and express worry that the same may happen to them. Counseling all patients on smoking cessation is important, as smoking has been identified as a major risk factor for this disease. The Age-Related Eye Disease Study (AREDS) trial showed a significant benefit of daily doses of vitamin C 500 mg, vitamin E 400 IU, beta-carotene 15 mg, zinc oxide 80 mg, and cupric oxide 2 mg in slowing the progression of disease in patients with ARMD. However, supplementation in patients without the disease has not shown any benefit in primary prevention. Furthermore, high levels of beta-carotene have been associated with increased risk of lung cancer in smokers. Thus, primary care physicians should ensure that their patients who smoke are not self-supplementing with beta-carotene. While there is no evidence for the benefit of AREDS-like supplementation in patients without the disease, these patients should be encouraged to consume a healthy diet with moderate amounts of these compounds.
One intervention already encouraged by all primary care providers is tight glucose control in diabetics to prevent the development or progression of diabetic retinopathy. The ACCORD study demonstrated a significantly lower rate of progression of diabetic retinopathy in patients randomized to the tight glycemic control group. Furthermore, it showed a significantly lower rate of retinopathy in patients with dyslipidemia randomized to fenofibrate and simvastatin versus placebo and simvastatin. This is a promising finding; however, further research is needed to explore the effect of fenofibrate on the progression of diabetic retinopathy before this can be recommended in all patients with type 2 diabetes and dyslipidemia.
Hypertension is another chronic, systemic disease with the potential to adversely affect eyesight. Elevated blood pressure has been well established as a cause of retinopathy; it also puts the patient at risk for other vision-threatening conditions such as artery or vein occlusions and ischemic optic neuropathy. It may also be a risk factor for glaucoma and age-related macular degeneration. Thus, controlling hypertension is a simple way to prevent loss of vision from a number of etiologies.
In summary, referring patients for screening eye exams allows for early intervention in asymptomatic disease. By reminding patients of the proper use of contact lenses, physicians can help to prevent permanent corneal damage secondary to microbial keratitis. At this time, the use of high-dose antioxidants and zinc has not been found to be effective in the primary prevention of age-related macular degeneration. Patients should be encouraged to consume a healthy diet consisting of antioxidants and vitamins. Tight glycemic control in diabetics and blood pressure control in hypertensives are two of the most effective ways for primary care physicians to help patients protect their vision. Reminding patients of the visual consequences of uncontrolled diabetes and hypertension may result in better compliance. Oftentimes there is nothing scarier to patients than losing their sight.
Dr. Nora Muakkassa is a recent medical student graduate, class of 2011 at NYU School of Medicine
Peer reviewed by David Howard, MD, Assistant Professor Dept. of Ophthalmology, NYU Langone Medical Center
Image courtesy of Wikimedia Commons.
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