The Nutritional Therapy Practitioner’s Guide to Supporting Dry Eye Syndrome
By Kat Carroll, NTP and reviewed by Donald A. Carroll, OD, NTP
Dry eye syndrome (DES) is the most common complaint to eye doctors. If you’ve ever experienced dry eyes, especially while trying to wear contact lenses, it is a real nuisance. But maintaining healthy terrain on the ocular surface is not just inconvenient; if DES goes untreated, it can cause fluctuations in vision, and the cornea can become scratched, scarred, and ulcerated.
The typical symptoms of DES include dryness, irritation, grittiness, burning, and difficulty reading for extended periods of time. Strangely enough, excessive tearing and watering are also indicative of DES. In extreme cases, light sensitivity, pain and diminished vision can result. DES is particularly common among peri and postmenopausal women; there is a gender bias and a hormonal aspect to this syndrome. How empowering would it be to have the proverbial “three easy steps to end dry eye” to offer your clients? How much more so if those steps avoided the use of any artificial tears, drugs like corticosteriods, or surgical procedures such as punctal plugs that prevent tear drainage from the punctum?
Medical solutions don’t reach the core of the problem. Only restoration of proper structure and function to the tear film will provide a permanent resolution to DES. Only after diet and lifestyle have been assessed carefully and addressed fully should we perhaps consider using remedial means to alleviate dry eye such as topical lubricant eye drops, corticosteroid eye drops, oral anti-inflammatory drugs or surgical methods like insertion of punctual plugs.
DES is best addressed first by nutritional therapy, supplementation and lifestyle education; particularly as there is a strong correlation between DES and systemic inflammatory processes such as diabetes and auto immune diseases like rheumatoid arthritis.
In our experience at the Medical Vision Center and Nutritional Visions Natural Health Center in Morton, Washington, the patients who take a disciplined and educated course of action to rectify their DES show remarkable success in eradicating the root of the dysfunction and thus effectively resolve their symptoms. We can’t treat the eye naturally without raising the general level of health in the rest of the body, and patients enjoy this added benefit.
In this article, we will discuss a few strategies the Nutritional Therapy Practitioner can employ (as part of the total body care that NTPs provide) which will restore structure and function to the eye. But first, let’s look at the characteristics of DES, its common causes, and the ocular layers that make up the tear film.
There are two types of dry eye:
Aqueous Dry Eye: caused by aqueous (water) insufficiency, which causes a decrease in tear production.
Evaporative Dry Eye: caused by blockage of the meibomian glands that line the lash margin. The limited secretion of oil by these glands leads to quick evaporation of tears. Tears that simply evaporate too fast.
Dry eyes can result from:
- Being in a perimenopausal or postmenopausal status
- Deficiencies in fatty acids and vitamins and minerals
- Longterm contact lens wear
- A side effect of many medications
- LASIK or cataract surgery
- Diabetes, rheumatoid arthritis (RA), and systemic inflammatory diseases
Environmental impacts affecting DES:
- Dry office environment
- Irritation from smoke or smoking
- Staring at the computer without blinking
Our tears are made up of three different layers: mucin or mucus layer, aqueous or water layer, and lipid or fat layer
- The mucin layer, which touches the cornea, nourishes the front of the eye. This layer serves as an anchor for the tear film, helping it adhere to the eye and keeps the eye moist.
- Aqueous from the lacrimal gland forms the middle layer of tear film, incorporating the water-soluble components. It provides moisture, oxygen, and nutrients to the cornea.
- The lipid layer is produced by the meibomiam glands of the eyelids. It is our first line of defense against evaporation, infection, solar radiation and injury to the outside of the ocular surface. It creates a smooth surface for light to pass through the eye. It also keeps the tears from evaporating and provides a smooth tear film over the cornea when we blink.
Each of the three layers is driven by nutrition. Each has varying concentrations of vitamins and minerals which promote proper structure and function to each of the segments. Educated Nutritional Therapy Practitioners already understand how to restore and/or maintain structural integrity in order to influence function at each level of the tear film. Repletion of nutrients that saturate ocular tissues is vital for influencing structure and creating proper function. As a result, vision is improved and contact lens wearers find a more comfortable fit.
The mucin layer requires Vitamin A in (the form of retinol) which plays a central role in the development of the mucin of the tear film. Vitamin A deficiency is a cause of Goblet cell atrophy and loss of the important innermost lubricating mucin layer.
The lacrimal gland’s secretions are promoted by micronutrients like zinc, magnesium, Vitamin C, Vitamin B6 and Vitamin B3 (niacin). Amazingly, the lacrimal gland has hormone receptors in it and tear film is influenced by hormonal fluctuations.
The oily layer needs essential fatty acids (both Omega 3 from flax, cod liver oil, and algae, and Omega 6 in the form of evening primrose oil, borage oil or black currant seed oil) in order to create structural integrity in its segment of the three part layer that makes up the ocular terrain.
Zinc is a major player in construction of a healthy corneal surface, as it has the highest concentration in the entire body in the cornea of the eye.
As we know, many people are deficient in zinc. We can administer the Zinc Challenge test as one measure in assessing the integrity of the cornea.
Bioindividuality is key
Bioindividuality is key when considering treatment options for DES; strategies become complex when we factor in:
- Smoking, which disrupts the way carotenoids are used in the eye and the smoke itself is an irritant which exacerbates DES
- Inflammatory, allergenic and/or nutritionally deficient dietary pattern
- Gallbladder removal surgery and subsequent diminished fat processing
- Gender bias to DES with predilection to peri and postmenopausal women
- DES occurring secondary to systemic illness such as diabetes or rheumatoid arthritis (RA).
- DES as a result of prescription and over-the-counter drug use.
- DES in post surgery (Lasik, PRK and Cataract) patients
Reducing systemic inflammation becomes the number one therapy for treating DES, which has an inflammatory component.
We teach a modified Mediterranean diet, removing gluten, dairy and known sensitivities to reduce inflammation. The Hale Project reported in JAMA in 2004, confirming the success of diet and lifestyle modifications (non-smoking, moderate exercise and whole foods, largely plant-based diet) in reducing mortality and morbidity from all causes after ten years in individuals aged 70-90. What a successful lifestyle program! What is good for the body is good for the eyes.
Initially a healthy inflammatory reaction serves purposes of tissue isolation and protection from further injury so that the body can initiate a healing response. However, an inflammatory response that does not turn itself off upsets the balance in our body. Through the modified Mediterranean Diet, our goal is to limit systemic inflammation by calming inflammation signals. One particular Medical Food we prescribe employs selective kinase response modulation to calm inflammation systemically which has a positive impact on supporting proper tear film layers as well as the whole system.
Combined with the Mediterranean Diet, currently the most effective treatment for DES we’ve used is a combination of Omega 3 and Omega 6 fatty acids, a blend of A, D, E, C and the cofactors B6, Biotin, magnesium and zinc.
But getting the materials to the “jobsite” is only half the picture. Transporting them to their optimal location is the rest of the goal. Adding digestive enzymes assures proper digestion and assimilation.
Gender bias and DES:
In a March 2007 study out of Bologna, Italy researchers determined that “subjective symptoms, tear production and stability, surface dryness and inflammation were significantly related to hormonal fluctuations in the menstrual cycle in perimenopausal women. In particular, the impairment of these functions appeared to be related to the estrogen peak occurring during the follicular phase, especially in patients with dry eye.”
Hormone balancing is an often overlooked aspect of repletion of nutrients. Both peri and postmenopausal women report an increased incidence of dry eye. Recall that there are hormone receptors in the lacrimal glands which respond to support. We also know that DES is correlated with hormone replacement therapy (HRT) use in postmenopausal women. Now that synthetic HRT has fallen out of favor, we can impact dry eye by aiming to regulate estrogen, progesterone, DHEA and testosterone naturally. I would encourage everyone to read Douglas Hall, M.D’s. excellent article entitled Nutritional Influences on Estrogen Metabolism to master this important and often overlooked aspect of repletion of nutrients.
The concept of macro and micro nutrient deficiency secondary to systemic disease and its impact on DES is fascinating to consider. DES can accompany systemic diseases like diabetes and RA. DES is made worse by prescription and OTC drugs and can also emerge as the result of multiple micronutrient deficiencies that occur as a result of their use. The resulting deficiencies can manifest as ocular disease, visual dysfunction or ocular conditions such as DES.
Those with diabetes have a higher incidence of DES and are a great example of being aware that certain disease states will require repletion of nutrients over and above a healthy population. Diabetics typically have about 30% less circulating Vitamin C than non diabetic individuals and less magnesium as well. They are already experiencing greater oxidative stress due to the disease process, and are compromised in vitamins and minerals unless they are eating exceptionally well or supplementing.
Studies reporting on nutrition and supplementation impact on DES are encouraging and growing in number. In an Indian study reported in 2006, we see the effect of deficiencies associated with systemic disease. Ophthalmic Epidemiology finds “Patients with RA in the Indian population have a significantly higher prevalence and severity of dry eye when compared to age and sex-matched controls.” If we are in a pro inflammatory state, we may develop other conditions.
Another 2006 study found that flax seed oil worked to reduce DES equally as well as the oral anti-inflammatory drug Doxycycline prescribed for severe dry eye. Colin C.K. Chan. MD speculated in the publication that the reason may be due to its anti-inflammatory, lipid-modifying properties. He presented his ideas at the annual meeting of the American Society of Cataract and Refractive Surgery.
We have much at our disposal today in the form of research, healthy dietary options, and supplements that can resolve even tough-to-resolve issues like Dry Eye Syndrome.