Preparation is key to fighting dry eye while traveling

As of April 2022, the Centers for Disease Control and Prevention proclaimed that 70% of Americans could stop wearing masks, with the hopes that many individuals and communities could resume some semblance of normal life. For many of us, that includes the freedom and ability to travel.

At the time of this writing, the most recent travel information from ustravel.org reported that more than 9 in 10 American travelers had travel plans in the next 6 months. This makes sense because after remaining homebound—as some would describe it—since early 2020, our wanderlust may be calling us away, aboard red-eyes and early morning flights to different climates, schedules, and elevations.

With changes to our routines, environments, and the ways in which we use our eyes, travel can sometimes awaken our old friend: dry eye.

Traveling considerations

The experience of symptoms such as burning, stinging, and irritation is so common that it has been called “traveler’s dry eye.” Because eye care practitioners (ECPs) know this is so common, we can alert patients on avoiding and, if need be, managing the symptoms.

From a traveler’s perspective, it is exciting to imagine packing clothing, toiletries, personal hygiene products, and medications ahead of a trip. But in terms of packing for our eyes, do we travel with extra contact lenses? Artificial tears? How should we prepare for their best comfort?

Airplane cabins, with their relatively low humidity, can cause an increase in aqueous tear evaporation that can intensify symptoms of dry eye. Logically, the lower the humidity in our surroundings, the more liquids (including tears) evaporate.¹

Compounding the arid cabin environment are 2 things: high-intensity personal air vents and the way many choose to spend their flight time, such as watching films or reading. Many studies have found that we blink far less often while reading or paying attention to a specific task (watching a movie, doing a crossword, or writing), which decreases the tear film wetting of the ocular surface.²

It is worse for those individuals who nap while wearing contact lenses, which not only creates discomfort from oxygen deprivation but also via the introduction of airborne pollutants during wear. This greatly increases the risk of an eye infection.³

Discussing these potential conditions with patients before they travel (and discouraging contact lens naps) can avoid having them land with true red eyes. The Figure shows an irritated, red right eye with 360° of blood vessel dilation, ciliary flush, and increased tear prism.

Effect of climate changes

A change in scenery at our destination can also come with a change of environment upon landing. From low-humidity locales like Denver, Colorado, to highly seasonally allergenic areas like Scranton, Pennsylvania, and hot, dry spots like Cairo, Egypt, it is not enough to only think of the flight to our place of adventure.

Changes in the local climate do not just affect our choice in outerwear; they also alter our tear film makeup. Increased allergens in the air—such as pollen, pollution, dust, smoke, and smog—can irritate not only our lungs and skin but also our eyes.

Allergic conjunctivitis sufferers, who often concurrently experience dry eye, may unexpectedly have symptoms off from their usual season. When in a new location, individuals who typically live in humid areas without dry eye indications may suddenly experience symptoms of irritation.

It is possible to check pollen counts as well as pollution levels. However, unless we are extraordinarily well-versed in how the numbers translate to personal symptoms, it may be useful to just think of those numbers broadly in terms of the irritants’ presence as potentially causing an annoyance.

Our activities and day schedules often change with travel. Many of us who practice indoors—with predictable daily patterns of computer use, breaks, and percentage of time working vs relaxing our eyes—often depart from the usual day activities. After all, isn’t this part of the reason we travel?

Some of us leave our practices and are suddenly on ATVs in the Moab desert, snorkeling in saline water in Crete, or high-velocity hang gliding outside of Honolulu.

Contact lenses that typically last a full day with comfort could no longer be capable of withstanding such diverse activities. Our aqueous tear film may not be able to hold on through speed-based activities or when in contact with the salty sea.

As our skin and hair note these environmental changes, so do our eyes. Some activities may be more predictable and others less so.

How then can we best prepare our patients for travel? Digging into our memory from 3 years ago, we unearth many helpful options.

Ophthalmic

1. Consider contact lens use.

Whether it is as simple as flying in glasses instead of contact lenses, decreasing wear time, or recommending daily disposable contact lens use during activities, it may be a good time to trial a daily modality. Discussing the merits of the various modalities is helpful, including changing replacement schedule, a new material, or oxygen permissibility.

2. Topical ophthalmic drops are worth traveling with.

Preservative-free options, with less chance of surface irritation, are preferable when possible. Artificial tears, gels, or ointments can be vital for restoring tear balance.

Those who suffer from allergies, or are aware they are traveling to a highly allergenic area, may want to consider packing ophthalmic antihistamines in their carry-on vs in checked luggage. Preloading with the above-described pharmaceuticals can be helpful—even if days or weeks prior to travel—for optimal ocular surface health before departure.

3. Reposition the air vent.

Dry air is pushed at high velocity, often aimed directly onto the passenger seat. This is vital for air circulation but can wreak havoc on tear film. On many flights the vents can be adjusted for full air flow—or even moved a few centimeters in any direction, continuing their vital circulatory work but sparing the aqueous layer.

Systemic

1. Have optimal systemic hydration.⁴

Whole-body hydration with nonalcoholic liquids decreases tear film osmolarity and increases the aqueous layer, building a better tear film. Hydrating before and during the flight and upon landing is critical.

2. Consider oral antihistamine use.

Some systemic antiallergic medications (diphenhydramine, loratadine), although very effective at blocking histamine, cross the blood-brain barrier and can decrease either the aqueous or mucin layers, potentially leading to tear film instability, which results in dry eyes.⁵

3. Think about decongestant use.

Cabin pressure in airplanes can lead to or exacerbate sinus symptoms. Decongestants in pills, liquids, or nasal sprays are very effective in ameliorating sinus symptoms, often including ingredients such as phenylephrine, pseudoephedrine, and oxymetazoline. But like antihistamines, they decrease tear production. Some products on drugstore shelves combine an antihistamine and a decongestant—truly the riskiest in terms of dry eye amplification.

The excitement of upcoming departures presents a unique opportunity for us as primary ECPs to best prepare our patients to get the most enjoyment from their travels.

Dry, irritated eyes can be a significant impediment to relaxing while traveling. Luckily, though, we hold the keys for best preparation and management. Each preparatory patient discussion may be unique and depend on that patient’s baseline, history, contact lens use, and destination.

Arming the patient with knowledge on various topical antihistamines, hyperosmotic solutions, and lubricants can ensure that they have the correct products when needed.

Dispensing wisdom on dosing, including both preparing in advance and management should things go awry, is vital for a patient’s confidence. Considering systemic medications and their effects can help prepare the patient for optimal comfort. Discussing various contact lens modalities as they best suit planned activities can enable patients to enjoy their adventuring more clearly.

For patients attached to monthly lenses, trialing a small amount of a daily disposable contact lens for certain activities can be a great experience. These travel conversations will hopefully become more common as the world reopens, reminding us of the vitality of our role in patients’ lives—at home and abroad.

References

1. Uchiyama E, Aronowicz JD, Butovich IA, McCulley JP. Increased evaporative rates in laboratory testing conditions simulating airplane cabin relative humidity: an important factor for dry eye syndrome. Eye Contact Lens. 2007;33(4):174-176. doi:10.1097/01.icl.0000252881.04636.5e

2. Wu Z, Begley CG, Port N, Bradley A, Braun R, King-Smith E. The effects of increasing ocular surface stimulation on blinking and tear secretion. Invest Ophthalmol Vis Sci. 2015;56(8):4211-4220. doi:10.1167/iovs.14-16313

3. Goodlaw E. Risk of infection from sleeping with contact lenses on: causes of risk. Optom Vis Sci. 1996;73(3):156-158. doi:10.1097/00006324-199603000-00005

4. Walsh NP, Fortes MB, Raymond-Barker P, et al. Is whole-body hydration an important consideration in dry eye? Invest Ophthalmol Vis Sci. 2012;53(10):6622-6627. doi:10.1167/iovs.12-10175

5. Foutch BK, Sandberg KA, Bennett ES, Naeger LL. Effects of oral antihistamines on tear volume, tear stability, and intraocular pressure. Vision (Basel). 2020;4(2):32. doi:10.3390/vision4020032