Dry eye disease (DED) goes beyond a simple inconvenience, leaving a well-documented impact on multiple aspects of life, including work productivity, physical health, and mental well-being.1
Its repercussions stretch even beyond these domains. Sleep disorders are particularly pronounced in patients with dry eye, leading to further health risks and a decline in overall health.2
Research indicates that cumulative sleep deprivation is linked to many chronic health problems, including heart disease, kidney disease, diabetes, stroke, obesity, depression, and even death.2,3 Insufficient sleep also contributes to motor vehicle accidents and workplace errors, resulting in numerous injuries and disabilities annually.4
While inquiring about sleep habits may seem unconventional for primary eyecare providers, it holds potential significance in managing DED and enhancing overall health outcomes for patients.
By incorporating questions about sleep into routine assessments, practitioners can gain valuable insights that may inform more holistic approaches to addressing DED and promoting wellness.
The link between sleep and dry eye
In a large study with over 71,000 participants, individuals with dry eye experienced significantly poor sleep quality, and this association was present in all ages and genders.5 Patients with dry eye are 1.5 times more likely to be poor sleepers.
In fact, highly symptomatic dry eye was rated as one of the top five conditions to reduce quality of sleep and its impact on sleep was similar to sleep apnea syndrome.5 Sleep disorders are particularly pronounced in patients with Sjögren’s syndrome, with an 81.7% prevalence of sleep disorders in patients with primary Sjögren’s syndrome.6
On the other hand, not surprisingly, poor sleep also leads to dry eye disease. Research indicates that individuals experiencing poor sleep were 50% more likely to suffer from dry eye compared to those with better sleep habits. Particularly, this diminished sleep quality significantly heightened the risk of developing highly symptomatic dry eye.5
Which came first…DED or poor sleep?
The relationship between dry eye and poor sleep quality is complex and can be bidirectional, meaning that one can exacerbate the other in a cyclical manner.
Although the exact mechanism underlying DED’s impact on sleep is still not well understood, depression, pain, and eye exposure at night seem to play a role.2 Dry eyes can lead to poor sleep due to discomfort and irritation, making it difficult for individuals to fall asleep or stay asleep throughout the night. The symptoms of DED can also induce psychologic distress from the disease itself.2,7
Among ophthalmic conditions, the highest prevalence of depression was observed in those with DED (29%), followed by individuals with glaucoma (25%), age-related macular degeneration (24%), and cataracts (23%).8 Depression is a common co-morbidity of sleep disorders. Depression may induce DED and sleep disorders, and in turn, ocular diseases could induce depression.7,8
Secondly, it is highly likely that the pain experienced by DED patients may be associated with sleep disorders. Patients with chronic fatigue syndrome and fibromyalgia experience chronic pain all over the body, and sleep disorders are highest amongst these patients.5 Pain is known to affect sleep quality and a low threshold of pain is linked to sleep disorders.2
Thirdly, eye exposure may be more common in patients with DED, and this also could lead to sleep difficulty. Patients may experience air and light exposure due to incomplete eyelid closure, producing inflammatory processes leading to DED, depression, and disrupted sleep.
Conversely, poor sleep also causes dry eye. A study by Lee et al. found that poor sleep leads to hyperosmolarity of the tears, reduced tear breakup time (TBUT), and increased ocular surface pain score.8 Although the exact mechanism is not well understood, a possible mechanism is that sleep deprivation increases stress hormones, including cortisol, epinephrine, and norepinephrine, which can reduce output from the lacrimal gland.9
How to inquire about sleep with dry eye patients
If you are seeing patients with dry eye, you are most definitely also encountering patients with poor sleep. Since these conditions are thought to exacerbate one another and contribute to the overall burden of disease, they should be assessed, especially in patients with highly symptomatic dry eye. In addition, whenever possible, treatment options should be considered for both conditions.
The most popular and validated self-report questionnaire is the Pittsburgh Sleep Quality Index (PSQI). Major parameters are sleep duration, sleep latency, sleep difficulty, subjective sleep, and sleep efficacy. A global PSQI score over 5 (0 to 21) indicates poor sleep quality.7
However, formal administration of the PSQI isn't always necessary to gauge sleep issues. Simple inquiries such as whether individuals struggle to initiate or maintain sleep, their subjective evaluation of sleep quality, instances of nocturnal awakenings, or disruptions caused by dry eye or sleep apnea, along with any medication usage for sleep support, can effectively reveal potential sleep disorders in patients.
Co-managing sleep issues in dry eye patients
If sleep issues are discovered, making the appropriate referral is important. Patients suspected of having sleep apnea should be referred to a their or sleep specialist for further evaluation, which typically involves a sleep study (polysomnography).
Treatment options for sleep apnea may include lifestyle changes, continuous positive airway pressure (CPAP) therapy, oral appliances, or surgery, depending on the severity of the condition. Proper management of sleep apnea is crucial as it can significantly impact overall health, leading to cardiovascular problems, daytime fatigue, and decreased quality of life if left untreated.
Furthermore, treating DED can also improve sleep. One study evaluated the effect of topical medication prescribed for the treatment of DED, including hyaluronate, mucin secretagogue, and steroid eye drops, on the sleep of patients with DED and found a significant improvement in the PSQI score.2
Tips on managing patients with poor sleep and dry eye
When talking to patients, emphasize the importance of a consistent sleep schedule and relaxing bedtime routines. Recommend turning down the lights and avoiding screens 2 hours before bedtime to improve sleep quality.
Take proactive measures to manage DED in patients with sleep disorders. Eyelid malpositions such as lagophthalmos and floppy eyelid syndrome can lead to poor lid closure, which can be a reason for poor sleep and dry eye disease.
Recommend using eye ointments at night to help provide additional moisture while sleeping. Moisture chamber goggles, such as Eyeseals 4.0 (EyeEco/PRN Vision Group), or taping the eyelids closed while sleeping can also be used to prevent the eye from unintended exposure or excessive drying due to incomplete lid closure.
Punctal plugs can be a key player in patients with lagophthalmos by increasing tear volume and helping to reduce dependency on artificial tears (while preserving the patient's natural tear film).
Patients should also be carefully examined for blepharitis or meibomian gland dysfunction (MGD).10,11 The presence of MGD leads to poor quality and quantity of meibum production, causing tear film instability, which can contribute to symptoms of morning dryness.
Using a humidifier in the bedroom to add moisture to the air can also help alleviate dryness. Additionally, avoiding exposure to irritants like smoke and fans, which can exacerbate dry eye symptoms, can be beneficial.
In conclusion
Due to the importance of sleep in the holistic management of DED, primary eyecare providers are encouraged to incorporate sleep assessments into dry eye evaluations.
This approach not only aids in the more effective management of DED but also promotes broader health and wellness, highlighting the interconnectedness of eye health and general physical and mental well-being.
