Each day, as optometrists, our patients ask us about ways they can protect their eyes or improve their vision. It can sometimes take more than a new glasses prescription. Vitamins and supplements can be important in improving the sight of our patients, and are often forgotten when addressing patient needs. Most significantly, patients should be reminded that it is preferable to eat foods rich in vitamins if possible, as opposed to adding additional supplements. Foods such as spinach and bell peppers are an easy addition to any diet for improved eye health. This article will act as a quick reference for optometrists on the latest research and what to recommend for specific ocular conditions.
What vitamins are good for the eyes?
Vitamin A is essential for healthy corneal development. Deficiency results from inadequate intake, fat malabsorption, or liver disorders. Common signs of Vitamin A deficiency are night blindness, conjunctival xerosis, Bitot's spots, corneal xerosis, a corneal ulcer covering less than 1/3 of the cornea, a corneal ulcer covering at least 1/3 of the cornea, keratomalacia, and corneal scarring. Vitamin A deficiency is rare in developed countries, and is typically treated by oral supplementation. Fruits and vegetables are rich in vitamin A.
In 2017, a study in glaucoma-prone mice indicated that when the mice were administered B3, the vitamin acted both “prophylactically and as an intervention.” This recent study may indicate that vitamin B3 may be a future addition for eye health and glaucoma management. As B3 treatment is not currently the standard of care, more research must be done in this area before it should be recommended to patients as a supplement. A well-balanced diet of meat, fish, and poultry, as well as avocados, peanuts, whole grains, mushrooms, green peas, and potatoes is a great natural source of B3.
What vitamins/supplements help with Dry Eye?
For years, treating patients with fish oil has been the standard in eye care. In 2015, a study showed that omega-3 fatty acids may improve the signs and symptoms of meibomian gland dysfunction. Meibomian glands provide the component to balancing the tear film, the lipids that reduce ocular surface water evaporation and prevent dry eye. The thought is that the omega-3 in fish oil reduces inflammation, including inflammation of the cornea, the underlying cause of dry eye. Fish oil contains two omega-3 fatty acids called docosahexaenoic acid, or DHA, and eicosapentaenoic acid, or EPA. These are thought to provide many health benefits, which include improving cardiovascular function by decreasing inflammation, mitigating peripheral artery disease, and through anti-coagulation. Additional studies have shown promising results in both weight management and cognitive function in patients with mild Alzheimer's disease.
As of April 2018, the National Institute of Health study found that Omega-3 fatty acids taken orally are no more effective at relieving dry eye symptoms than a placebo. Patients’ symptoms were measured as their change from baseline in the Ocular Surface Disease Index. After 12 months, mean symptom scores for people in both groups had improved substantially, but there was no significant difference in the degree of symptom improvement between the groups.
The verdict is still out on the benefits of omega-3 fatty acids in patients with dry eye. Many doctors still err on the side of precaution and continue to recommend omega-3s because they are unlikely to do harm. Additional research may show them to be beneficial in the future, but recommending omega-3 for dry eye is still the standard of care for these patients.
Patients with a vitamin D deficiency have shown to have dry eye and impaired tear function. Researchers believe that vitamin D may play a protective role by “enhancing tear film parameters and reducing ocular surface inflammation.” Therefore, when patients do not get enough Vitamin D in their diets, they may begin to experience inconsistently blurry vision, eyes that burn and/or tear, and even red eyes. Many suggest that patients with dry eye should be evaluated for vitamin D deficiency. Salmon is an excellent food for increasing Vitamin D, and exposure to sunlight helps, as well.
What vitamins/supplements are good for treating Macular Degeneration?
Vitamin C/Vitamin E/Zinc
The Age-Related Eye Disease Study (AREDS) conducted by the National Institute of Health was to learn more about the history and risk factors of age-related macular degeneration (AMD). Results show that high levels of antioxidants and zinc reduce the risk of advanced macular degeneration. Patients with known macular changes should take a specific eye vitamin, like Ocuvite or PreserVision, that has the recommended levels of Vitamins C, E, antioxidants, and zinc. Additionally, foods such as spinach and bell peppers, daily UV protection, and quitting smoking can possibly reduce progression.
In 2013, researchers conducted AREDS 2, adding omega-3 and lutein and zeaxanthin to the formula. Lutein and zeaxanthin were added in place of beta-carotene. Beta-carotene had shown to increase the risk of lung cancer in smokers. Omega-3 fatty acids did not show to have an affect, but lutein and zeaxanthin were shown to significantly reduce the risk of advanced ARMD and vision loss. Per the AREDs 2 study, eye vitamins for the treatment of ARMD should include: 500 mg of Vitamins C, 400 Iu of Vitamin E, 80 mg Zinc, 2 mg Copper, 10 mg Lutein, and 2 mg Zeaxanthin.
A recent study sought to determine the effects of thiamin, riboflavin, and folate on geographic atrophy in patients with Macular Degeneration. Neither folate nor any B vitamin had any effect on neovascular AMD; however, high folate intake was associated with a reduced risk of progression to geographic atrophy. No effective therapeutic strategy for geographic atrophy (GA) is available at this time. Doctors should monitor research in this area in order to provide the best recommendation for patients as additional research develops.
Are there vitamins or supplements to prevent cataracts?
The idea that vitamins and supplements may prevent cataracts begins with the idea of free radicals. Vitamins may prevent free radical damage. However, as of 2016, research has shown that vitamin supplements are not effective against cataracts. Studies show that patients taking these products developed cataracts just as often as those taking a placebo. The researchers analyzed nine studies involving a total of almost 120,000 people between the ages of 35 and 85. Vitamin C, vitamin E and/or beta-carotene were used for up to 12 years by participants. The researchers considered the results of this study to be so clear that they did not see a need for any further research in this area.
Recommending healthy food options, and/or prescribing vitamins and supplements is just as important for your patients’ vision as the correct glasses prescription. Often, as optometrists, we forget to prescribe for the entire person. As research evolves, we must be alert to new research in order to best care for our patients. Recommend supplements and diets based on current studies to patients with common ocular conditions like ARMD and Dry Eye disease. Closely monitor the addition of B13 for glaucoma patients and omega-3 for dry eye. Don’t forget, it is always important to remind your patients that the best nutrients are found in the foods that we eat. Eating healthy should be the first recommendation!