BLOG: Dry eye disease is more than an eye problem
Not surprisingly, most eye care specialists see dry eye disease as an ocular problem. But what would our treatment strategies look like if we instead approached it as a local manifestation of a systemic problem?
Fifteen years ago, I was thrown deep into the study of the autonomic nervous system after receiving a diagnosis of postural orthostatic tachycardia syndrome, or POTS. A form of autonomic nervous system failure or dysautonomia, my POTS developed after a bout with an upper respiratory infection. I became plagued by a puzzling range of symptoms including dramatic heart rate and blood pressure changes, waves of tremors and weakness, halted digestion, breathing difficulty, dramatic insomnia, mood swings, short-term memory impairment and intolerance to even the slightest temperature changes. Sadly, my 8-year-old soon presented with the condition after three viral infections.
My quest to get answers to a condition for which there was insufficient understanding spurred me to undertake my own research, and I subsequently established Genetic Disease Investigators LLC. Much research and numerous clinical trials eventually yielded some answers to the puzzle of autonomic dysfunction, including the role of the vagus nerve and the neurotransmitter acetylcholine in POTS. Interestingly, when addressing these issues, it became apparent that patients’ chronic dry eye was also resolving. Ultimately, I received three patents for unique supplements based on a decade of research, founded TJ Nutrition and launched POTS Care to treat and counsel other patients.
When I saw the reversal of dry eye disease (DED), I backed up to explore how this supplement was not only stimulating the vagus nerve (nicotinic), but also the nerves serving the lacrimal gland (muscarinic). Significant effort went into improving this formulation to maximize tear production (lacrimal functional unit) while minimizing inflammation (vagus nerve).
The combination of addressing both simultaneously was helping patients with DED who were not suffering with POTS, and I had to figure out why.
DED, a multifactorial disease, has a significant inflammatory component. For effective treatment of symptoms, both local and systemic causes must be identified. When underlying systemic inflammation continues, DED cannot be resolved, and overall health will suffer.
Normal tear formation is a complex neurological process, under tight neurological control. The vagus nerve and the lacrimal nerve are part of the parasympathetic nervous system, with the former controlling the body's inflammatory cells and the latter controlling aqueous tear production and meibomian gland function.
When the homeostasis of normal tear production is disrupted, the underlying cause must be addressed. This may not always be an ocular issue, however, as systemic inflammatory conditions can also affect the neurology of tear production. It is well known, for example, that inflammatory conditions such as Sjögren’s syndrome, Lupus erythematosus and rheumatoid arthritis cause DED.
However, chronic inflammation affects a much larger population. It is part of normal aging – “inflammaging” – and it is present in a vast array of other conditions such as autoimmunity, metabolic syndrome, endocrine disorders and mast cell problems. This often goes unrecognized and unaddressed because the traditional markers of inflammation are often normal. This means that the effect of chronic, systemic inflammation on neurological function, including the autonomic nervous system, often remains undiagnosed and untreated. Patients not only develop dry eyes, but they do not feel as good as they could and often blame stress, getting older or not eating right for some symptoms. We can do better.
The autonomic nervous system is at the heart of the neurological process that is responsible for tear production. This control is both a local and systemic process; therefore, both need to be addressed in DED treatment. Had my autonomic nervous system not failed, I would have never explored this so deeply.
In my next blog, I will further explore the link between systemic and local inflammation, the autonomic nervous system and neurological DED.
- Calonge M, et al. Ocul Immunol Inflamm. 2010;doi:10.3109/09273941003721926.
- Dartt DA. Prog Retin Eye Res. 2009;doi:10.1016/j.preteyeres.2009.04.003.
- Di Zazzo A, et al. Invest Ophthalmol Vis Sci. 2019;doi:10.1167/iovs.18-25822.
- Kam WR. Invest Ophthalmol Vis Sci. 2011;doi:10.1167/iovs.11-8113.
For more information:
Diana Driscoll, OD, an authority on the autonomic nervous system, is the clinical director of POTS Care and the founder and president of Genetic Disease Investigators and TJ Nutrition. She can be reached at firstname.lastname@example.org.