Environmental, Behavioral Triggers Linked To Dry Eye Disease Flares

Kids going to school in the smog
Three kids wearing pollution masks and backpacks are walking to school in the smog. The air is thick with mist and smog.
A study shows the link between ocular surface dryness and air conditioning, pollution, watching television, and surgery.

Real-world triggers and characteristics of dry eye disease (DED) flares can include environmental factors, such as air conditioning, wind, low humidity, or pollution, as well as behavioral factors, such as reading, watching television, and surgery, according to study findings published in The Ocular Surface. The research team identified these triggers after reviewing various studies.

Recently DED flares have been more frequently recognized; however, due to the lack of systemic studies, characteristics of DED flares have not been well described. To address this knowledge gap, a team of investigators conducted a review to identify evidence for DED flares and to illustrate their characteristics in literature including triggers, patient-reported characteristics, clinician-measured characteristics, and changes in tear molecules. 

“In this rapid evidence assessment…a flare was defined as an episode of worsening DED symptoms that may or may not be accompanied by a worsening in clinical signs and occurs in response to an extrinsic trigger or challenge in patients with previously diagnosed DED,” the study shows.

A total of 22 studies were included in the analysis and subcategorized as evidence from daily life (n=5), evidence from cataract and refractive surgery (n=5), and evidence from controlled environment models (n=12). The researchers report that continued exposure to environmental triggers may lead to the disruption of tear film homeostasis, which can result in worsening signs and symptoms. 

Study results suggest that patients diagnosed with DED could have flares resulting from environmental triggers that could last from a period of weeks to months. Air conditioning, wind, reading, low humidity, watching TV, and increased ground-level ozone concentration were reported signs of triggers across daily life studies. Three observational studies reported exacerbations in signs and symptoms of flares in dry eye disease due to short-term (2 hours) exposure to low-humidity controlled environments. States of “hyperevaporative dry eye” were triggered by high wind, air conditioning, and low humidity.  

Compared with patients with preoperative DED, patients who underwent cataract surgery and refractive surgery had significant exacerbations in signs and symptoms. Results suggested that postsurgical exacerbations were more predictable and longer-lasting than flares occurring in daily life, which may be due to the severity of surgical trauma compared with environmental triggers. Preoperative dry eye was a significant risk factor for postoperative dry eye. 

“It is recommended that clinicians treat DED preoperatively before finalizing a refractive surgical plan and that they continue the treatment regimen postoperatively in anticipation of potential iatrogenic progression,” according to the investigators. 

Using contained environments, 3 studies assess the changes in tear molecules and noted patterns in the inflammatory protease MMP-9. Inflammatory cytokines such as interleukin-1β upregulate the expression of MMP-9, which has been associated with disease severity. In addition, it has been characterized as a potential biomarker and therapeutic target for dry eye disease. EGF, an abundant tear growth factor, and interleukin-6 have also shown potential as inflammatory biomarkers for flares. 

Despite these findings, there are no current guidelines or strategies for the short-term treatment of dry eye flares. “Further research is essential to define and establish the characteristics of DED flares and to assist clinicians in the early diagnosis and treatment of patients experiencing flares,” investigators conclude. 

Disclosure: Multiple study authors declared affiliations with the biotech, pharmaceutical, and/or device companies. The rapid evidence assessment to support this report was funded by Kala Pharmaceuticals, Inc. Please refer to the original article for a full list of disclosures. 


Starr CE, Dana R, Pflugfelder SC, et al. Dry eye disease flares: a rapid evidence assessment. Ocul Surf. Published online July 22, 2021. doi:10.1016/j.jtos.2021.07.001