Chronic stress can create an imbalance in mental health and the gut microbiome, leading to inflammation and consequential effects on eye health.
We can’t seem to escape stress. At the office, we are juggling schedules, managing teams, and rushing to hit deadlines—all while trying to balance work and home life. Over time, the impact of this strain affects our health and well-being when not properly addressed.
Chronic stress triggers a cascade of stress hormones that produce well-orchestrated physiological changes that eventually wreak havoc on eye health. The most obvious clinical signs we detect as eye care professionals are the following:
Beyond this, part of a practitioner’s role is to recognize potential undiagnosed or unmanaged chronic diseases. In this way, we strive to ensure patients receive proper care to minimize the short- and long-term risk of vision loss. However, so many of these cases can be managed with lifestyle changes, including exercise, sleep, and nutrition.
The link between stress and the eyes is not fully understood, but we do know that the stress cascade begins in the amygdala, the area of the brain that processes emotion, which then sends a signal to the hypothalamus.In turn, the hypothalamus activates the sympathetic nervous system by triggering the autonomic nerves to the adrenal glands. These glands release the hormone epinephrine (also known as adrenaline) into the bloodstream and initiate several physiological changes. As the initial surge of epinephrine subsides, the hypothalamus activates the hypothalamic-pituitary-adrenal (HPA) axis as the secondary response. This network consists of the hypothalamus, the pituitary gland, and the adrenal glands.1
Chronic low-level stress keeps the HPA axis activated. The hypothalamus releases corticotropin-releasing hormone, which stimulates the pituitary gland, initiating the release of adrenocorticotropic hormone. This hormone makes its way to the adrenal glands, resulting in cortisol release (the universal stress marker). As the stressor passes, cortisol levels fall. The parasympathetic nervous system slows down and then dampens the stress response.
Our body attempts to keep a state of allostasis, the ability to achieve stability by adapting to a changing environment. Over time, elevated cortisol levels and increased epinephrine can lead to increased risk of heart disease, buildup of fat tissue, increased appetite, gut dysbiosis, poor sleep, anxiety, and eventually chronic eye disease and inflammation, otherwise known as allostatic overload.2
So how do we manage it? If a practitioner can be more aware of the contributors of stress to eye health, then a guided journey will begin to manage the underlying cause.
This opens the topic of personalized medicine while evaluating each case cautiously and thoroughly. If clinicians want to differentiate their services, it is important to discuss prevention with patients rather than be late to the game discussing treatment. Start with a simple health history and a medication list. This could trigger the initial discovery of stress/anxiety, gastrointestinal conditions, or chronic vascular disease. Continue the process throughout the examination based on symptoms and ocular findings. Here are some further questions to consider:
Uncovering some of the basic HPA triggers from stress will help you understand the root of the problems. The quality sleep recommended for adults is at least 7 hours each night.3 According to the Centers for Disease Control and Prevention, insufficient sleep quantity and quality have been linked to the development and progression of several chronic diseases and conditions, including type 2 diabetes, cardiovascular disease, obesity, thyroid disease, and depression. With perpetuated sleep deficiency, crucial nutrients can be depleted, such as melatonin, the lack of which can exacerbate sleep quality and quantity. Additionally, snoring or sleep apnea increases the risk for known conditions such as glaucoma, retinal edema, hypertensive retinopathy or diabetic retinopathy, and floppy eyelid syndrome, which leads to dry eyes.4 It is important to obtain a referral for these patients in the case of suspected sleep apnea.
Caffeine can lead to adrenal burnout in high amounts; therefore, managing caffeine or coffee intake can also help manage the effects on the HPA pathway. In high doses, caffeine has been shown to activate the HPA axis. Excessive caffeine has also been shown to induce anxiety, potentiate panic attacks, and elevate glucocorticoid levels.5 According to the FDA, it is recommended that healthy adults consume no more than 400 mg of caffeine daily—approximately 4 or 5 cups of coffee—an amount not generally associated with dangerous, negative effects. However, there is wide variation in how sensitive individuals are to the effects of caffeine and how fast they metabolize it.6
Microbiome dysbiosis is a common contributor to the inflammatory cascade. As we know today, our gut biome is the epicenter of bodily regulation, being responsible for 70% to 80% of immune cells present in the gut.7 Often, acute or chronic stress will influence poor nutritional choices and eating patterns. After a while, a compromised microbiome can lead to malnutrition, mental illness, and inflammation. Nutrition is one of the most recognized modifying factors of the gut-brain axis. The routes of communication between the microbiota and brain are slowly being discovered, which include the vagus nerve, gut hormone signaling, the immune system, tryptophan metabolism, and microbial metabolites such as short-chain fatty acids (SCFAs).8 If the microbiome is compromised, homeostasis is disturbed, nutrients are not absorbed, and infection and inflammation rise, which all cause undesirable responses to eye function, rosacea, and overall health.
SCFAs, the main metabolites produced in the colon by bacterial fermentation of dietary fibers and resistant starch, are speculated to play a key role in neuroimmunoendocrine regulation.9 Leaky gut, or the increased permeability of the intestinal barrier, can increase the production of cytokines and affect the blood-brain barrier. Conversely, the gut microbiota can interact with the central nervous system via gut modulation or directly via metabolites and endotoxin translocation from the intestine to the blood circulation. This can also occur through vagus nerve stimulation, ultimately shaping behavior and cognitive function. This is where dietary intervention can play a role in improving immune responses and decreasing inflammation.
Managing medications can be an important factor to consider. One example is the common prescription medication for management of anxiety, depression, and stress known as selective serotonin reuptake inhibitors (SSRIs). The 6 primary SSRIs are commonly known in the United States as fluoxetine, citalopram, escitalopram, paroxetine, sertraline, and fluvoxamine. These first-line agents have been linked to inflammation and dry eyes but have an unlikely risk of cataract formation.10-12The presumed pathophysiology is the upregulation of serotonin found in tear film and the aqueous humor that induces inflammatory and apoptotic pathways in the corneal epithelium and lens fibers. In these cases, management of ocular surface disease is necessary to help control symptoms of dry eyes and inflammation. Therefore, it is imperative to reveal medications that could be contributing to visual disturbances.
Self-care recommendations such as encouraging movement can change a patient’s trajectory toward reducing stress. Yoga and breathing exercises can influence how we start the day or even get through a tense situation.13,14 Meditation, time spent outdoors, connections with friends and family, or anything that could transition someone away from the stress-causing environment will slow down the HPA cascade.15
What are some things practitioners can do in these cases once the culprit is uncovered? Manage these cases with an integrative approach around nutrition and lifestyle modifications. Start by planting the seed, encouraging self-evaluation methods and simple at-home therapies such as the following:
When it comes to determining the root cause of unexplained ocular findings, do not underestimate the effects of stress. Preventive measures, especially in these cases, will go a long way to minimizing persistent ocular disease of any kind.