“If you have goggles or an eye shield, you should use it.” ~ Anthony Fauci, July 30th, 2020
We had heard enough from Fauci by the time this comment was made in mid-2020 to begin automatically tuning out his frequently contradictory advice. What if we had given weight to this comment and explored why he began recommending goggles (yet never donned them himself)?
While I’m not surprised that the inner anatomy of the face including ocular ducts and connectivity within structures aren’t common knowledge, I expected more of a reaction from the medical community regarding Fauci’s push for eye protection. Not only do medical professionals take extensive coursework on human anatomy — they are required to meet annually with an Industrial Hygienist for fit tested, hazard-specific kit for each exposure setting , including ocular protection. This testing process requires going into detail about each exposure setting and required donning and doffing practices within the scope of their professional duties.
Instead of elaborating on his recommendation, Fauci just publicly hushed on the issue and folks carried on, obediently masked up yet entirely neglectful of their nasolacrimal ducts. Shame, shame.
These are the structures of the lacrimal apparatus connecting ocular and nasal pathways. Basically, the eye drains into the nasal cavity. None of the talking heads of the medical community ever seem to bring up that these parts of the body connect with one another, and while we hear about masks ad nauseam three entire years after the onset of the SARS-CoV-2 pandemic, no one is arguing with strangers on the internet about goggles.
Bernie Sanders was recently praised for being the only person at the February, 2023 State of the Union donning a (sub-grade, non-mitigating) respirator, but eye spy something fishy. It was noted that he kept removing his glasses, as they were fogging up.
Those who have donned respirators have experienced that exhale emissions are generally redirected out of the nose bridge (or out of side gaps if improperly sealed). This is the exhale emission plume create by a fitted, unvalved N95 respirator:
This plume of warm, moist respiratory emissions is what causes glasses to fog. This is precisely why I continue to argue that masks are NOT source control for respiratory aerosols, because these apparatuses are not designed nor intended to protect others from your emissions, but solely for protection of the wearer. The ASTM agrees with me on this matter:
The American Society for Testing and Materials (ASTM) Standard Specification for Barrier Face Coverings F3502-21 Note 2 states, “There are currently no established methods for measuring outward leakage from a barrier face covering, medical mask, or respirator. Nothing in this standard addresses or implies a quantitative assessment of outward leakage and no claims can be made about the degree to which a barrier face covering reduces emission of human-generated particles.”
Additionally, Note 5 states, “There are currently no specific accepted techniques that are available to measure outward leakage from a barrier face covering or other products. Thus, no claims may be made with respect to the degree of source control offered by the barrier face covering based on the leakage assessment.”
So does it matter if your neighbor’s exhale emissions are directed in your face for the duration of your 6-hour flight?
Absolutely. Imagine sitting between these two fine fellas with your eyes exposed, and their emission plumes directed right in your face.
In mitigation of aerosol hazards, eye protection is a standard part of required kit, because those from the correct domain of expertise, Industrial Hygiene, know enough about human anatomy to remember the interconnectivity of facial structures.
Ocular transmission of SARS-CoV-2
There has been a great deal of focus on respiratory protection since the start of the pandemic, but ocular transmission was already established for SARS-CoV-1.
“SARS-CoV-1 has been shown to be transmitted through direct contact or with droplet or aerosolized particle contact with the mucous membranes of the eyes, nose and mouth. Indeed, during the 2003 SARS-CoV-1 outbreak in Toronto, health care workers who failed to wear eye protection in caring for patients infected with SARS-CoV-1 had a higher rate of seroconversion.”
We are beginning to see mounting research on ocular transmission for SARS-CoV-2 emerge, as well, traveling through the nasolacrimal duct from the eye, draining into the sinus cavity.
“There is evidence that SARS-CoV-2 may either directly infect cells on the ocular surface, or virus can be carried by tears through the nasolacrimal duct to infect the nasal or gastrointestinal epithelium.”
“The nasolacrimal system provides an anatomic connection between the ocular surface and the upper respiratory tract. When a drop is instilled into the eye, even though some of it is absorbed by the cornea and the conjunctiva, most of it is drained into the nasal cavity through the nasolacrimal canal and is subsequently transferred to the upper respiratory or the gastrointestinal tract.”
“SARS-CoV-2 on the ocular surface can be transferred to different systems along with tears through the nasolacrimal route.”
Seldom did ocular exposure result in eye infection, while systemic infections occurred regularly. Ocular exposure cannot always be determined as the point of contact for this reason, as an eye infection does not always coincide with systemic infection.
The nasolacrimal duct is often discussed in ocular transmission research, but this is not the sole ocular transmission pathway discussed.
“There are two pathways by which ocular exposure could lead to systemic transmission of the SARS-CoV-2 virus. (1) Direct infection of ocular tissues including cornea, conjunctiva, lacrimal gland, meibomian glands from virus exposure and (2) virus in the tears, which then goes through the nasolacrimal duct to infect the nasal or gastrointestinal epithelium.”
Additionally, research is being conducted on the usage of ocular secretions in transmitting SARS-CoV-2.
“Then here comes the question, whether SARS-CoV-2 detected in conjunctival secretions and tears is an infectious virus? Colavita et al inoculated Vero E6 cells with the first RNA positive ocular sample obtained from a COVID-19 patient. Cytopathic effect was observed 5 days post-inoculation, and viral replication was confirmed by real-time RT-PCR in spent cell medium. Hui et al also isolated SARS-CoV-2 virus from a nasopharyngeal aspirate specimen and a throat swab of a COVID-19 patient. The isolated virus not only infected human conjunctival explants but also infected more extensively and reached higher infectious viral titers than SARS-CoV.”
According to this study, ocular secretions were highly infectious.
“The ocular surface can serve as a reservoir and source of contagion for SARS-CoV-2. SARS-CoV-2 can be transmitted to the ocular surface through hand-eye contact and aerosols, and then transfer to other systems through nasolacrimal route and hematogenous metastasis. The possibility of ocular transmission of SARS-CoV-2 cannot be ignored.”
This paper also has a focus on aerosols coming into contact with ocular mucosa.
“Once aerosols form, SARS-CoV-2 can bind to the ACE2 on the exposed ocular mucosa to cause infection. In order to prevent aerosols from contacting the eye surface, eye protection cannot be ignored.”
An additional area explored in this analysis discusses rhesus macaques wherein solely those inoculated through the ocular route became infected.
“If the ocular surface is the portal for SARS-CoV-2 to enter, where does the virus transfer after entering? An animal experiment reveals the possible nasolacrimal routes of SARS-CoV-2 transfer from the ocular surface. Five rhesus macaques were inoculated with 1×106 50% tissue-culture infectious doses of SARS-CoV-2. Only in the conjunctival swabs of rhesus macaques inoculated via conjunctival route could the SARS-CoV-2 be detected. Conjunctival swabs of the rhesus macaques that were inoculated via intragastric or intratracheal route were negative. Three days post conjunctival inoculation, rhesus macaques presented mild interstitial pneumonia. Autopsies showed that SARS-CoV-2 was detectable in the nasolacrimal system tissues, including the lacrimal gland, conjunctiva, nasal cavity, and throat, which connected the eyes and respiratory tract on anatomy.”
An additional macaque study had similar findings.
“Deng et al. showed that SARS-CoV-2 infection could be induced by ocular surface inoculation in an experimental animal model using macaques. Although the researchers detected the virus in conjunctival swabs only on the first day after inoculation, they continued to detect it in nasal and throat swabs 1-7 days after the inoculation. Their findings demonstrated that the viral load in the airway mucosa was much higher than that in the ocular surface. They euthanized and necropsied one of the conjunctival inoculated-animals and found that the virus had spread to the nasolacrimal system and ocular tissue, nasal cavity, pharynx, trachea, tissues in the oral cavity, tissues in the lower-left lobe of the lung, inguinal and perirectal lymph node, stomach, duode-num, cecum, and ileum. They also found a specific IgG antibody, indicating that the animal was infected with SARS-CoV-2 via the ocular surface route.”
While the nasolacrimal route is the primary focus in most current research, the blood-retinal barrier (BRB) is also discussed as a possible pathway.
“Once it reaches the ocular surface, SARS-CoV-2 could invade the conjunctiva and iris under the mediation of ACE2 and CD147, another possible receptor for SARS-CoV-2 on host cells. De Figueiredo et al described the following possible pathways. After reaching blood capillaries and then choroid plexus, the virus reaches the blood-retinal barrier (BRB), which expresses both ACE2 and CD147 in retinal pigment epithelial cells and blood vessel endothelial cells. Since CD147 mediates the breakdown of neurovascular blood barriers, the virus can cross the BRB and enter into blood.”
There has been a push recently to bring back masks for Respiratory Syncytial Virus (RSV), especially in schools, as this pathogen largely impacts youth populations, yet ocular transmission is a proven method of infectivity for RSV.
In this paper, intranasal dosing of the given pathogen resulted in onset of illness for nearly all respiratory pathogens studied. It reviews transmission routes and minimum infective dose for Influenza, Rhinovirus, Coxsackievirus, Adenovirus, RSV, Enteric Viruses, Rotavirus, Norovirus, and Echovirus, including ocular transmission.
“The infective doses of rhinoviruses in the nose and eyes are thought to be comparable because the virus does not infect the eyes but appears to travel from the eyes to the nasal mucosa via the tear duct.”
“Hall et al. (1981) investigated the infectivity of RSV A2 strain administered by nose, eye, and mouth in adult volunteers. They reported that the virus may infect by eye or nose and both routes appear to be equally sensitive. A dose of 1.6 × 105 TCID50 infected three of the four volunteers given either into the eyes or nose while only one out of the eight were infected via mouth inoculation, and this was thought to be due to secondary spread of the virus.”
“RSV A2 had poor infectivity when administered via the mouth but was shown to infect by eye and nose and both routes appear to be equally sensitive to the virus.”
“Bynoe et al. (1961) found that colds could be produced almost as readily by applying virus by nasal and conjunctival swabs as by giving nasal drops to volunteers.”
Would masks save schools from RSV circulation? Most kids have robust immune systems, with a very, very small percentage of the youth population undergoing chemotherapy or taking immunosuppressives, who usually are not on campus for in-person learning. But for those seeking protection and in-person instruction, we must not set them up for immune bombardment by offering a false sense of security while feigning ignorance of other viable transmission routes. Masks are not the answer.
Ocular transmission of respiratory pathogens hasn’t been a focal point of study, but with other pathogens and mounting research on SARS-CoV-2 showing such ease of systemic onset for this transmission route, more attention should be given to this area of research.
Consider all of the people you’ve seen donning masks or respirators over these past three years, assured in the merit of their virtue. How many still got sick? Did you ever once see someone donning goggles? Are we ever going to get around to discussing exhaustion of the hierarchy of controls, or are actual mitigating measures too taboo, too fringe?
TLDR: Ocular transmission is a viable method of transmission for SARS-CoV-2. Masks are not source control. Even N95s aren’t going to fix this. And all child masks are unregulated, untested, unethical, and unsafe, with zero efficacy, fit, term of wear, or medical clearance standards, and with ocular transmission being a proven route of transmission for RSV, masks aren’t going to fix that issue, either.