The Association Between Eyes And Respiratory Health

Medical News: Chronic respiratory diseases (CRDs) are a significant global health burden, with conditions ranging from asthma and chronic obstructive pulmonary disease (COPD) to pulmonary hypertension and interstitial lung disease. While these diseases primarily affect the lungs, recent research has uncovered an intriguing connection between respiratory health and ocular well-being.


Graphical Abstract - The Association Between Eyes And Respiratory Health

This Medical News report covers a study review by researchers from Uppsala University-Sweden, Swedish University of Agricultural Sciences-Sweden, University of Technology Sydney-Australia, University of New South Wales-Australia, Saveetha University-India, Graphic Era Hill University-India, Suresh Gyan Vihar University-India, International Medical University-Malaysia, Lovely Professional University-India and Macquarie University-Australia that delves ito an emerging concept, known as the "lung-eye axis," and explores the complex interplay between these two seemingly unrelated systems. Understanding this relationship could pave the way for novel diagnostic and therapeutic strategies.
 
The Lung-Eye Axis: A New Frontier in Medical Research
The lung-eye axis suggests a bidirectional relationship between respiratory and ocular health. This means that respiratory diseases may influence eye conditions and vice versa. The eye, being constantly exposed to the external environment and possessing a unique immune status, serves as an important indicator of systemic health, including the state of the respiratory system.
 
Immunological Crosstalk
At the core of this axis is the immune system, which plays a critical role in both respiratory and ocular health. The mucosal immune system, present in both the respiratory tract and the ocular surface, serves as the first line of defense against pathogens and allergens. This system comprises a network of epithelial cells, immune cells, and molecular mediators that work together to maintain homeostasis and combat external insults.
 
In both the respiratory and ocular systems, specific immunoglobulins, particularly IgA, play a crucial role in neutralizing pathogens. The ocular surface, protected by the tear film and various immune mechanisms, is capable of systematic removal of antigens and microbes. Similarly, the respiratory tract employs a variety of immune cells to initiate and modulate responses against inhaled pathogens.
 
The Ocular Microbiome and Its Impact on Lung Health
The microbiome, a vast ecosystem of microorganisms residing in and around the human body, significantly influences overall health. While the gut microbiome has received much attention, the ocular microbiome is now being recognized for its importance. This microbial community, primarily composed of bacteria, fungi, and viruses, maintains ocular health and may have far-reaching implications for respiratory health.
 
Recent research suggests that the ocular microbiome can influence lung health through the dissemination of micr oorganisms and their products from the eyes to the respiratory tract. This interaction can modulate local immune responses, potentially supporting or disrupting immune defense mechanisms in the lungs.
 
Additionally, ocular dysbiosis (imbalance in the ocular microbiome) can lead to chronic inflammation, which may extend to the lungs and contribute to respiratory conditions.
 
Environmental Irritants and the Lung-Eye Connection
The eye's exposure to environmental irritants, such as pollutants, smoke, and chemical vapors, can trigger systemic inflammatory responses. When the ocular surface is irritated, it activates nerve endings that release neuropeptides, initiating local and systemic inflammatory processes. This can exacerbate or contribute to the progression of lung diseases.
 
Studies have shown that populations exposed to high levels of air pollution experience increased rates of both ocular irritation and respiratory conditions. Experimental models have demonstrated that exposure to irritants can enhance inflammation in both the ocular and respiratory systems, highlighting the interconnected nature of these responses.
 
The Eye as a Gateway for Respiratory Viruses
The anatomical and functional connections between the eye and the respiratory system provide a basis for considering the eye as a potential entry point for respiratory viruses. Respiratory viruses like rhinovirus, influenza, and coronaviruses can be transmitted via respiratory droplets that come into contact with the eyes. The conjunctiva, a mucous membrane covering the eye, is particularly susceptible to these droplets.
 
Evidence from Respiratory Syncytial Virus (RSV)
RSV, a common respiratory virus, has been shown to infect both the eyes and the respiratory system. Studies have demonstrated that RSV can infect conjunctival and corneal cells, leading to respiratory symptoms. The virus can travel from the eye to the respiratory tract via the nasolacrimal system, highlighting the eye's role in respiratory virus transmission.
 
Insights from the COVID-19 Pandemic
The SARS-CoV-2 virus, responsible for the COVID-19 pandemic, has further underscored the eye's role in respiratory health. The virus can infect ocular tissues, and its primary entry proteins, ACE2 and TMPRSS2, are present in both the eyes and the respiratory tract. While the eye's role as an entry point for SARS-CoV-2 is still under investigation, the virus's presence in ocular tissues and its potential for systemic transmission through the eyes have significant implications for understanding respiratory infections.
 
Therapeutic Implications and Future Research
Understanding the lung-eye axis opens new avenues for managing chronic respiratory diseases. Future research should focus on the following areas:
 
-Longitudinal Studies: Long-term studies tracking changes in the ocular microbiome and their impact on lung health.
 
-Microbial Transfer Mechanisms: Research to elucidate how ocular microbes reach the respiratory tract and their consequences.
 
-Microbiome Interventions: Investigating probiotics or microbiome transplantation as potential treatments.
 
-Microbiome Profiling: Developing standardized methods for profiling the ocular microbiome.
 
Conclusion: Bridging the Gap Between Ocular and Respiratory Health
The lung-eye axis represents a fascinating intersection of respiratory and ocular health, revealing how these systems influence each other. By exploring this connection, researchers and clinicians can develop integrated approaches to diagnose and treat chronic respiratory diseases, ultimately improving overall well-being. As we delve deeper into this emerging field, the potential for innovative therapeutic strategies becomes increasingly promising, highlighting the importance of a holistic view of human health.
 
The study findings were published in the peer reviewed journal: Life Sciences.
https://www.sciencedirect.com/science/article/pii/S0024320524003205
 
For the latest on the lung-eye axis, keep on logging to Thailand Medical News.
 
Read Also:
https://www.thailandmedical.news/news/breaking-h5n1-genotype-affecting-cows-in-america-possibly-gains-entry-into-humans-via-the-eyes-thru-the-new-pb2-e67k-mutation
 
https://www.thailandmedical.news/news/breaking-news:-new-report-in-lancet-confirms-that-coronavirus-can-spread-through-eyes
 
https://www.thailandmedical.news/news/virus-research-shows-that-mask-alone-not-sufficient-as-protective-goggles-also-required-by-healthcare-staff-and-others-to-prevent-contracting-sars-cov
 
https://www.thailandmedical.news/news/covid-19-news-uk-study-validates-that-use-of-protective-eyewear-reduces-risk-of-sars-cov-2-infection
 
https://www.thailandmedical.news/news/sars-cov-2-is-able-to-cross-the-blood-retinal-barrier-and-cause-damage-to-the-eyes
 
https://www.thailandmedical.news/news/covid-19-news-various-new-case-reports-show-that-sar-cov-2-is-causing-lots-of-new-eye-and-vision-issues-especially-in-post-covid-phases