Dry eye has a profound effect on quality of life. While we have a full armamentarium of treatments to offer patients, we can’t always account for the impact of certain day-to-day lifestyle choices or situations when managing this chronic and often debilitating disease. Patients often want to know what else they can do to get through each day, in addition to the dry-eye treatments provided by their eye-care provider.
For years, ophthalmologists have offered up suggestions for lifestyle modification such as adding humidifiers to bedrooms, trying to blink more often or incorporating more fish into one’s diet. But what does the literature tell us? The Tear Film & Ocular Surface Society (TFOS) Workshop, “A Lifestyle Epidemic: Ocular Surface Disease” was initiated to answer this question. This Workshop was the first global panel of experts (a total of 158 members from 38 countries around the world) to undertake a comprehensive evidence-based review of the literature on how our various lifestyle and societal factors impact the ocular surface.
Eight reports covering contact lens wear, cosmetics, digital screen usage, elective medications and procedures, climate, lifestyle, nutrition and societal challenges were published. Three additional subcommittees focused on evidence quality, industry liaising and public awareness. Evidence was assessed using the Academy’s three-level Preferred Practice Pattern guidelines for evidence grading. In parallel with the narrative reviews, members of each topic area subcommittee worked with the evidence quality subcommittee to answer a unique key question using systematic review methodology.
In many instances, there wasn’t enough high-quality evidence to draw definitive conclusions about a given factor’s effect on the ocular surface. Hopefully these reports will inspire others to fill in the gaps with new research.
While all eye-care practitioners are encouraged to read the full report, below you will find some of the key findings from each subcommittee report.
Contact Lenses
Many of the day-to-day choices that contact lens wearers make can have marked consequences on ocular surface health. Findings showed that sleeping in contacts is the single largest risk factor for contact lens-related adverse events, including microbial keratitis, corneal ulcers and corneal infections.
Other risk factors included nonadherence to contact lens maintenance protocols and replacement schedules, both of which will negatively affect safety and performance. It’s important to remind patients to clean and replace cases periodically and to avoid exposing contact lenses to tap water. Topping off solution increases the risk of microbial keratitis by 2.25 times and poor storage case hygiene practices were associated with a 3.7-times increased risk. Good lens hygiene is especially important in challenging environments, such as high levels of dust, air pollution and chemical exposure.
Additionally, the report indicated that purchasing poor-quality contact lenses, showering and swimming while wearing contact lenses, failing to see an eye-care provider regularly, wearing lenses when unwell or resuming wear too soon after ophthalmic surgery also increased the risk of ocular surface complications and dry eye.
Daily disposable contact lenses have a number of established benefits compared with weekly or monthly lenses, and the report confirmed this, citing lower rates of inflammatory-related complications and better visual acuity outcomes following microbial keratitis.
Interestingly, the findings showed that contact lens-associated risks weren’t directly impacted by the COVID-19 pandemic. External factors such as mask-associated dry eye, increased screen time and exposure to hand sanitizer can certainly affect lens performance, but there wasn’t a lot of high-quality data demonstrating direct impact. Despite this, because contact lens wear may reduce tear-film quality and exacerbate dry eye, it’s recommended that contact lens wearers stop using lenses if they become infected with COVID-19. ‘Long COVID’ has been linked to corneal epithelial nerve loss and an increase in corneal immune cell density.
The contact lens report’s systematic review sought to examine associations between lifestyle factors and soft contact lens drop-out rates. The researchers looked at 34 studies (15 randomized controlled trials and 19 cohort studies). The group identified discomfort as the most frequently reported reason for drop-out (35 percent), followed by lens handling (33 percent), vision quality with multifocals and loss of interest. Ocular discomfort was most often linked to feelings of dryness. Though the influence of lifestyle factors remains poorly understood and more research is needed, the report ultimately concluded that contact lens wear enhances quality of life when used appropriately.
Cosmetics
Humans have been using cosmetics for thousands of years, and though it’s less common to find mercury in cosmetics nowadays, there still remain plenty of ocular surface toxins to be aware of. This report examined common cosmetic ingredients and their effects on the ocular surface.
The thin skin around the eyes and eyelids permits easy absorption of chemicals. Most cosmetics aren’t intended to go on the ocular surface, but it’s not uncommon for these products to migrate into the eye or eyelids. This is a common cause of or source of exacerbation for dry-eye disease symptoms since these products often contain ingredients that are toxic to the ocular surface and eyelids (many of which are classified as allergens, irritants, carcinogens, immunosuppressants, toxins, endocrine disruptors, mutagens or tumor promotors).
In addition to common culprits such as mascara, eyeliner, eyelash glue and foundations that may migrate into the eye and block meibomian glands or obstruct lacrimal pathways, skincare items such as retinoid creams may cause meibomian gland changes and salicylic acid cleansers may lead to ocular surface toxicity if they come into contact with the eye. Many products marketed as “natural” also contain eye irritants such as castor oil, gold, tea tree oil and talc that may cause contact dermatitis.
Cosmetics aren’t widely regulated in the United States. The FDA estimates that around 12,500 chemicals are used in cosmetics but fewer than 20 percent of these have been reviewed for safety by experts in the Cosmetic Ingredient Review.
Some of the key toxic ingredients to be aware of include parabens, phenoxyethanol, chlorphenesin, formaldehyde and benzalkonium chloride:
• Parabens. Parabens are very common in the United States, found in more than 22,000 products. They’re toxic to human corneal, conjunctival and meibomian gland epithelial cells in vitro. They’re also allergens and endocrine disruptors and possess estrogen latency and antiandrogen activity.
• Phenoxyethanol. Even in concentrations one-tenth of those allowed for consumer consumption, this drug decreases meibomian gland epithelial cell survival. This compound has also been demonstrated to induce hepatotoxicity, renal toxicity and hemolysis in many species.
• Chlorphenesin. Found in more than 1,300 cosmetics, this drug in 300-fold-lower concentrations than allowed has also been shown to reduce meibomian gland epithelial cell survival.
• Benzalkonium chloride. BAK amounts in cosmetics can be 20,000 times lower than approved levels and still be toxic to the ocular surface. In fact, concentrations hundreds-fold lower than the human limit for commercial products were found to kill all human corneal, conjunctival and meibomian gland epithelial cells in vitro within 18 hours. In vivo models demonstrated effects including tear-film instability, goblet cell loss, conjunctival squamous metaplasia and apoptosis, corneal neurotoxicity and corneal epithelial barrier disruption. We see signs of epithelial damage on the ocular surface with BAK-containing eyedrops, and we certainly see these signs in BAK-containing cosmetics as well.
• Formaldehyde. Similarly, formaldehyde concentrations 2,000 times lower than accepted levels in cosmetics are toxic to the ocular surface and also have carcinogenic properties. The International Agency for Research on Cancer has classified formaldehyde as a human carcinogen, yet it remains a common ingredient in many cosmetics.
In addition to toxic ingredient awareness, be sure to remind patients to pay attention to their cosmetics’ expiration dates. Certain products may go rancid after a period of time, and repeated use of a cosmetic product over time introduces microbes and other contaminants into the container. The report found that 35 percent of mascaras had a microbial presence after three months of use, and another study reported that 79 percent of used mascaras tested positive for Staphylococcus aureus and 13 percent for Pseudomonas aeruginosa. Product contamination is related to the amount of use, the age of the product and the number of users. Sharing makeup products (e.g., among friends or tester products in stores) can also transfer viruses and Demodex mites. Dirty makeup application tools may also play host to bacteria and microbes.
Cosmetic procedures including Botox, fillers, platelet-rich plasma injections, tattooing, eyelid piercing, eyelash curling, eyelash extensions, microneedling and skin resurfacing also pose potential risks to the ocular surface through damage, inflammation or migration of bacteria.
This report’s systematic review examined randomized controlled trial evidence for ocular surface signs and symptoms with the use of eyelash growth products. Patient reported symptoms and clinical parameters such as fluorescein staining, tear breakup time and osmolarity were assessed, as were secondary outcomes such as eyelash length, thickness and incidence of ocular adverse events. Unfortunately, none of the 14 eligible trials in the review reported on either of the two prespecified primary review outcomes associated with symptoms and signs based on validated systems, so consequently, given the lack of available literature, it wasn’t possible to answer the key questions. Based on the low-certainty findings we do have, it seems likely that eyelash growth products such as bimatoprost may lead to ocular adverse events seen with other prostaglandin analogues, such as irritation, stinging, itching or meibomian gland dysfunction. More high-quality studies in the future will help us learn more to educate eye-care providers and patients.
Digital Environment
One of the goals of this impact report was to develop a unified definition for digital eye strain. Prior to this, there was no agreed-upon criteria to assess the impact of digital devices on the ocular surface or to differentiate true eye strain caused by viewing digital screens from dry eye exacerbated by screen time. The current validated questionnaires, such as the Computer Vision Syndrome Questionnaire, don’t differentiate between overlapping symptoms with and without digital screen use.
It’s important to be able to properly diagnose digital eye strain since there are other conditions such as uncorrected refractive error or binocular vision problems like strabismus that may masquerade as digital eye strain. We want to be able to identify the true underlying cause—perhaps a patient has esotropia or cranial nerve palsy—and treat it in a timely and appropriate way.
The TFOS definition for digital eye strain is “the development or exacerbation of recurrent ocular symptoms and/or signs related specifically to digital device screen viewing.” It can occur as early as 20 minutes into device use and usually occurs after one, four and five hours of screen usage. According to the report, “a diagnosis should be able to differentiate a change in symptoms and/or signs that occur in a digital but not in an equivalent non-digital environment, conducted for the same duration, that exceeds the noise of repeated measures.”
Patients must report development or exacerbation of ocular symptoms specifically related to screen use. Typical symptoms of digital eye strain may include burning, headache, eye redness, photophobia, tearing, repeated frequent blinking, itching, blurred vision, near double vision and foreign body sensation.
Addressing digital eye strain can be undertaken from multiple fronts. The report’s systematic review looked at several possible treatments and identified oral omega-3 supplementation as a likely effective treatment, due to its anti-inflammatory properties. Antioxidants and blue-light blocking glasses, on the other hand, showed no effects on reducing digital eye strain. Somewhat effective treatments included artificial tears and using apps to set reminders to blink and take breaks from screen usage or follow the 20/20/20 rule.
Patients can also try to alter their device settings, such as reading in Dark Mode, which can reduce the accommodative load and improve visual acuity performance; adjusting screen brightness to mimic ambient light; using e-ink or e-paper devices; increasing display size/resolution to improve text readability; and ensuring good head and neck posture.
Elective Medications and Procedures
Medication-induced dry eye is already on many clinicians’ radars, with preserved artificial tears and glaucoma drops ranking high among possible causes or contributors. We know that preservatives in eyedrops, especially BAK, can have a toxic effect on the ocular surface, breaking down the tear film, damaging corneal epithelial cells, corneal nerves and meibomian glands. Alternatives include preservative-free drops or those with milder preservatives such as Polyquad, Purite, SofZia and sodium perborate.
Other medications affecting ocular surface health and contributing to dry eye include:
- antihistamines
- mast cell stabilizers
- NSAIDs
- isotretinoin
- topical alpha adrenergic receptor agonists
- corticosteroid
- hydroxychloroquine
- ivermectin
- hormone replacement therapy
- antidepressants
- cannabis
- anti-androgens
- tamsulosin (Flomax).
Additionally, titanium dioxide and zinc oxide nanoparticles, found in mineral sunscreens, are cytotoxic to corneal cells. Eye whitening products are also not recommended, with 32.4 percent of users diagnosed with dry eye after undergoing the procedure (with only 2.8 percent initially presenting with dry eye).
One of the most severe complications of a medication is toxic epidermal necrolysis/Stevens Johnson Syndrome. Use of antimicrobials such as trimethoprim, sulfamethoxazole, sulfonamide antibiotics, aminopenicillins, quinolones and cephalosporins were risk factors for developing this condition and other severe ocular surface alterations. For any drug-induced reaction, it’s important to identify the cause and stop use or switch to a less toxic alternative.
Punctal plugs and low-level light therapy both demonstrated positive effects in dry eye, with low-level light therapy improving meibomian gland dysfunction. Interestingly, manuka honey eye drops were found to improve ocular surface staining and meibomian gland expressibility. Adverse effects included redness, itching, inflammation and allergic reactions.
As for elective procedures, those that lift the brow or alter the eyelid may increase corneal dryness by altering eyelid position, eyelid closure or damaging the cornea or lacrimal structures. Upper blepharoplasty alone may alleviate dry-eye symptoms. Ptosis surgery wasn’t found to worsen dry-eye symptoms. Corneal refractive surgery is also a well-known contributor to dry eye.
The systemic review of this report focused on SMILE, reporting a high satisfaction index, improvements in quality of life and minimal interference with the ocular surface. Based on the findings, SMILE is a reasonable alternative to other corneal refractive procedures and is considered a good option for treating refractive error. Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up. More high-quality prospective studies are needed to further distinguish these vision correcting techniques.
Environmental Conditions
This report identified several environmental variables that contribute to dry eye, some of which are modifiable and others not. Here are the key conditions affecting the ocular surface:
• Temperature. Temperature affects ocular surface homeostasis directly and indirectly and can precipitate ocular surface disease symptoms. Extremely high or low temperature in the indoor and outdoor environment have been associated with dry eye. One study reported that in an indoor environment at 22.2 to 25.6 degrees Celsius (72 to 78 degrees Fahrenheit), a 1-degree Celsius temperature decrease improved dry-eye symptoms in 19 percent of participants. Temperature variations may also be implicated in allergic conjunctivitis.
• Humidity. Population-based studies revealed a negative association between humidity and risk of dry-eye disease. High indoor humidity (30 to 40 percent) was associated with lower ocular surface symptoms. Humidifiers set to 40 percent, especially in the bedroom, can help alleviate dry eye. Low humidity environments such as deserts, airplane cabins and certain geographic regions can aggravate symptoms. Allergies and adenovirus conjunctivitis were negatively correlated with low humidity.
• Wind speed. The current literature provides very little evidence for wind speed and ocular surface diseases, with studies limited to case reports or retrospective reviews. Based on these, we know corneal frostbite and desiccation keratitis were found to occur with prolonged exposure to high wind speeds and sub-zero temperatures in ultra-marathon runners. Corneal freezing has been described in military freefall parachutists exposed to freezing temperatures and high winds. Higher occurrences of corneal ulcers have been found in onion harvesters in southern Taiwan, a monsoon area with prevailing gusty winds.
• Altitude. At higher altitudes, conditions are cold, dry, hypobaric and hypoxic, with strong ultraviolet radiation and more hours of sunshine. The most common ocular surface disease related to altitude is pterygium. There is also increased risk for photokeratitis.
Dewpoint, the temperature to which air must be cooled to reach maximum water saturation, is positively correlated with tear breakup time. A higher dewpoint (e.g., when there’s fog and precipitation) may be a protective factor for dry eye.
• Allergens. High concentrations of indoor and outdoor allergens such as mold spores, grasses, weeds, tree pollen, dust mites and pet dander exacerbate dry eye and conjunctivitis, as do longer and earlier allergy seasons.
• Air pollution. Evidence shows that some airborne pollutants may be harmful to the ocular surface. These include a mixture of toxic chemicals and compounds including carbon monoxide, nitrogen dioxide, sulfur dioxide, ozone and particulate matter less than 10 µm. Ocular surface disease symptoms may be worse among individuals living near sources of particulate matter such as volcanoes and wildfires, fuel combustion, factories, transportation, agriculture and air conditioning systems or units. Primary Sjogren’s syndrome was associated with occupational chemical solvent exposures (chlorinated and aromatic solvents).
One of the less often acknowledged dimensions of air pollution is sick-house or sick-building syndrome. Patients with this condition have worsening ocular surface symptoms when in a particular house or building due to mold, allergens, dust and toxins such as paint thinners and construction materials.
The environmental systematic review examined the associations between outdoor environment pollution and dry-eye disease symptoms and signs in humans in 19 studies from 10 different countries. These studies confirm increased dry-eye disease with air pollution (from NO2) and soil pollution (from chromium), but no increase in dry-eye disease with air pollution from CO or particulate matter <10 µm.
Nutrition
Poor diet is the second highest risk factor for dry-eye disease, leading to chronic inflammation, impaired immunity and gut microbiome dysbiosis. This report considered ocular surface effects of micro- and macronutrients, water, eating habits and systemic disease. Positive effects on the ocular surface were found with some of the following:
• Omega-3s. A higher ratio of omega-6s to omega-3s was found to be proinflammatory while a lower ratio was anti-inflammatory. Increasing omega-6 intake conferred an approximately 2.5-times higher risk of developing dry-eye symptoms while every gram of omega-3 consumed was associated with a 30-percent reduction in dry-eye risk. The ideal ratio of omega-3 to omega-6 reported was 4:1.
The Mediterranean diet, which is high in omega-3s, was shown to decrease the signs and symptoms of dry eye vs. baseline in patients with Sjögren’s syndrome in one randomized study.
• Certain micronutrients. Strong evidence was also found for vitamin A, vitamin B12, vitamin C and vitamin D. Vitamin A was found to decrease stress symptoms compared to no treatment. Limited evidence was reported for selenium and lactoferrin.
• Some dietary supplements. A randomized controlled trial found that curcumin or turmeric decreased dry-eye symptoms and increased Schirmer scores and tear breakup time. Additionally, a combination of curcumin, lutein, zeaxanthin and vitamin D3 taken for eight weeks decreased dry-eye symptoms.
Eating honey conferred no change in dry-eye symptoms but did increase tear breakup time and Schirmer’s score, according to a double-masked eight-week randomized controlled trial.
Interestingly, the large-scale literature review turned up a misconception about hydration. A population-based study on water intake with approximately 31,000 individuals concluded that water intake wasn’t protective for eye dryness.
Worsening dry eye was linked to cytokines, eating disorders such as anorexia (but not bulimia), food intolerances and food allergies. The effect of intentional food restriction on the ocular surface remains unclear and better-quality studies are needed on dietary effects.
Several systemic disorders that are affected by nutrition and diet such as inflammatory bowel disorder and celiac disease also demonstrated associations with ocular surface health, possibly through inflammation and disruption of the body’s ability to process and distribute certain nutrients. A systematic review investigated the effects of intentional food restriction on ocular surface health; of the 25 included studies, most investigated Ramadan fasting (56 percent), followed by bariatric surgery (16 percent), anorexia nervosa (16 percent), but none were judged to be of high quality, with no randomized-controlled trials.
Lifestyle Challenges
The lifestyle subcommittee examined ocular surface effects related to mental health challenges, physical factors such as chronic pain, and recreational drug use.
Almost 30 percent of individuals with dry eye have depression. Meta-analyses show that dry-eye disease symptom scores are significantly associated with depression severity scores. Multiple studies have reported no relationships between dry-eye disease symptoms and signs with depression but given the high risk of these two conditions coexisting, and the fact that SSRI antidepressant medications have been reported to cause ocular surface changes, it’s worth learning if your patient is suffering from or being treated for depression.
Similarly, anxiety disorders also demonstrated a positive association with dry-eye disease, with studies finding a higher proportion of dry-eye patients with anxiety-related diagnoses, including post-traumatic stress disorder. Stress may flare dry-eye symptoms.
Unsurprisingly, sleep quality and dry eye were associated. Patients who exhibited poor sleep quality, less time spent asleep or had more sleep disturbances had a higher prevalence of dry eye. In terms of possible mechanisms, the literature tells us that sleep deprivation leads to epithelial disruption, lipid abnormalities, morphologic changes to the microvilli and decreased tear production. Resting for 14 days after sleep deprivation reversed these observed changes in one study.
Patients with obstructive sleep apnea who use continuous positive airway pressure (CPAP) machines may experience dry eye from air leakage around the mask. The same has been found among face mask wearers. In a study of mask-associated dry eye, 27 percent reported worsening symptoms while wearing a mask. Mask wear greater or equal to six hours per day, five days per week resulted in an increase of dry-eye symptoms compared to pre-pandemic scores.
Chronic pain is a risk factor for dry eye. A systematic review reported that dry-eye disease in adults with primary pain disorders was more likely compared with a control population. Migraine, fibromyalgia, irritable bowel syndrome and back pain are just a few of the pain conditions with links to dry eye.
Limited and contradictory data was available for tobacco and cannabis use, with one meta-analysis finding no significant association between tobacco use and dry eye and three general population studies finding significant associations. Cannabis data showed potential long-term decreased corneal endothelial density, but dry-eye studies were limited. Alcohol consumption and dry eye was thought to be part of a larger issue involving poor nutrition and vitamin A deficiency.
Caffeine may have a beneficial effect on dry eye. Two prospective placebo-controlled cross-over studies demonstrated increased tear meniscus height and higher Schirmer’s test scores with caffeine use.
Overall, the evidence supports comorbidity between chronic conditions and dry-eye disease but mostly pertaining to symptoms rather than signs. The effect of recreational drugs on the eye is dependent on the actions of the drugs and their methods of delivery.
Societal Challenges
As with many other medical conditions, societal factors such as education, access to care and health-care utilization play a role in ocular surface disease presentation, management, prioritization and outcomes. Many elements of this report were previously covered in other TFOS Lifestyle Workshop Reports, including systemic diseases, age, sex, race, smoking status, COVID-19 effects and regional climate. This report went on to investigate socio-economic and cultural effects on ocular surface disease, as well as the impact of employment, poverty, sanitation, violence and trauma and access to health-care services.
Many societal challenges are associated with acute and chronic ocular surface disease but the presence of confounders requires further research with appropriately powered studies. This report noted that the effects of sex may be confounded by social and gender constructs, affecting access to health care, employment, poverty and education. Additionally, different reported rates of ocular surface among Indigenous versus non-Indigenous populations may be affected by access to health care, poverty, trauma and marginalization.
Alluded to briefly with sick-building syndrome, working and living conditions can put individuals at increased risk for dry eye and other ocular surface diseases. Poverty and poor sanitation also contribute to increased risk, as well as violence, war, immigration, food insecurity, water quality and climate variations.
Dr. Starr is an associate professor of ophthalmology, director of refractive surgery, director of the cornea fellowship and director of ophthalmic education at Weill Cornell Medicine. He is the chair of the TFOS public awareness subcommittee.
Further Reading
1. Alves M, Asbell P, Dogru M, et al. TFOS Lifestyle Report: Impact of environmental conditions on the ocular surface. The Ocular Surface 2023;29:1-52. doi:10.1016/j.jtos.2023.04.007.
2. Galor A, Britten-Jones AC, Feng Y, et al. TFOS Lifestyle: Impact of lifestyle challenges on the ocular surface. The Ocular Surface 2023;28:262-303. doi:10.1016/j.jtos.2023.04.008.
3. Gomes JAP, Azar DT, Baudouin C, et al. TFOS Lifestyle: Impact of elective medications and procedures on the ocular surface. The Ocular Surface 2023;29:331-385. doi:10.1016/j.jtos.2023.04.011.
4. Jones L, Efron N, Bandamwar K, et al. TFOS Lifestyle: Impact of contact lenses on the ocular surface. The Ocular Surface 2023;29:175-219. doi:10.1016/j.jtos.2023.04.010.
5. Markoulli M, Ahmad S, Arcot J, et al. TFOS Lifestyle: Impact of nutrition on the ocular surface. The Ocular Surface 2023;29:226-271. doi:10.1016/j.jtos.2023.04.003.
6. Stapleton F, Abad JC, Barabino S, et al. TFOS lifestyle: Impact of societal challenges on the ocular surface. The Ocular Surface 2023;28:165-199. doi:10.1016/j.jtos.2023.04.006.
7. Sullivan DA, Da Costa AX, Del Duca E, et al. TFOS Lifestyle: Impact of cosmetics on the ocular surface. The Ocular Surface 2023;29:77-130. doi:10.1016/j.jtos.2023.04.005.
8. Wolffsohn JS, Lingham G, Downie LE, et al. TFOS Lifestyle: Impact of the digital environment on the ocular surface. The Ocular Surface 2023;28:213-252. doi:10.1016/j.jtos.2023.04.004.
