I know that like me, you are probably sick of all the coronavirus-related news. I’m not going to write about it regularly of course. I have other topics in mind. But this week I couldn’t pass this up. I think it is important. I’ve been following this for months. And I think it is something you might find interesting.
Before I actually get to the topic of the heading- don’t worry I won’t take too long- I want to thank you for signing up for my newsletter. Chances are you already know me on Twitter. And here is a little bit more about me and what this newsletter is going to be about. Twitter is great. It is instantaneous and breathless. But Twitter is also horrible because it is instantaneous and breathless.
In this newsletter, I’m going to try to dive deeper into one topic or idea which I think (and hope) you find interesting. I’m also working on a few projects. I will keep you informed about them.
Oh, and one more thing, before I forget. I won’t send these newsletters out more than once a week, and you can unsubscribe at any time.
Now, on to the topic.
Can wearing eyeglasses actually lower the chance of getting infected with SARS-CoV-2, the coronavirus that causes COVID-19?
You’ve heard the guidance on maintaining appropriate distance, wearing facemasks, and handwashing to prevent the chance of infection. I’m guessing you’ve likely not heard much about eye-protection to prevent infection. And that is for good reason too. As far as I’m aware, neither the World Health Organization (WHO) nor the U.S. Centers for Disease Control and Protection (CDC) have issued any guidance on eye-protection.
Does that mean that eyeglasses don’t work to prevent SARS-CoV-2? No, not exactly. We have to remember that this is a new virus and it took a until the middle of the year for WHO to definitively recommend wearing facemasks to prevent infection. There has to be a certain threshold of reliable data on the mode of transmission, and some evidence that the measure works effectively. And as we’ve already seen, this can take time.
Now, I’ve been assiduously following the research on transmission of SARS-CoV-2 since late January. And I have to tell you that in February, there was an intriguing letter to the prestigious medical journal The Lancet. The letter was in response to the first description of SARS-CoV-2 in the medical literature which had been published in The Lancet a month earlier. The broad conclusions of the letter can be summed up in one sentence:
As ophthalmologists, we believe that transmission of 2019-nCoV through the eyes was ignored.
(As an aside, recall that at the time of submission of the letter SARS-CoV-2 was called the 2019 novel coronavirus).
The authors then went on to provide a plausible (but not confirmed) case of an infection that might have occurred through the eyes. They then provided a possible mechanism for infection occurring when droplets laden with virus particles contaminate the conjunctival epithelium. Earlier, another coronavirus, SARS coronavirus had been shown to be transmitted through mucus membranes in the eyes. The authors hinted that this was possible with SARS-CoV-2 too. They concluded the letter with the following:
The fact that exposed mucous membranes and unprotected eyes increased the risk of SARS-CoV transmission suggests that exposure of unprotected eyes to 2019-nCoV could cause acute respiratory infection.
So far so good.
Then, in March, in a paper published in JAMA Ophthalmology, researchers shed light on the presence of SARS-CoV-2 in the tears of patients suffering from COVID-19.
This is what they found:
One-third of patients with COVID-19 had ocular abnormalities, which frequently occurred in patients with more severe COVID-19. Although there is a low prevalence of SARS-CoV-2 in tears, it is possible to transmit via the eyes.
So, now that researchers established that there was a plausible mechanism for the spread of SARS-CoV-2 through eyes, we could look at ways of preventing spread. Mind you, we still didn’t know just how prevalent spread through this route might be compared to other well established means of infection (via the mouth and nose) but we had a reason to see if physically protecting eyes could lower the chance of infection. It’s important to stress now that observing that wearing a faceshield or eyeglasses lowers the chance of infection would not definitively establish it as the cause, but it would still be a good sign that we were on the right track and we needed to look into it.
With me so far?
As you probably know, faceshields have been recommended since the early month of the pandemic for those who were flying on airplanes. They were not meant to serve as a replacement for facemasks or social distancing, but as an added layer of protection.
Then, a very important study showing the effectiveness of social distancing, facemasks, and eye-protection (yes, eye-protection) was published in The Lancet in June. To quote the paper:
Eye protection also was associated with less infection.
Now, we’re talking.
So where are we at today?
Well, just today a group published a paper in JAMA Ophthalmology that looked at a group of 276 patients hospitalized with COVID-19. They found that the proportion of daily wearers of eyeglasses was lower than that of the local population (5.8% vs 31.5%).
They concluded that daily wearers of eyeglasses for eight or more hours are less likely to be infected with SARS-CoV-2.
Now, this is one small study of symptomatic sick patients in a hospital so it is hard to extrapolate from these observations. More studies are certainly needed. But it does raise the possibility of an incremental benefit from wearing standard eyeglasses (in addition to masks and social distancing).
A companion piece to the article summed up the possible benefit quite nicely:
Although eyeglasses do not provide the same extent of eye protection as goggles or a face shield, they may serve as a partial barrier that reduces the inoculum of virus in a manner similar to what has been observed for cloth masks.
Does this mean you should probably go out and get eyeglasses if you don’t need them and are not in high-risk settings? Probably not. Or at least, not yet. But if you do wear eyeglasses (like I do) it is one small thing to keep in mind when deciding between a pair and contact lenses.
…
The link for the hardcover “COVID-19: Separating Fact from Fiction” is now available on Amazon’s Indian site.
OK, friend, that’s all for me for today. I’ll keep you posted on any other positive actionable news on the pandemic. Next time, I’ll post on something different.
Take care and do drop me a note letting me know how you’re doing.
Anirban
Frequent blinking and washing of conjunctival sac by tears may also contribute to opthalmic route of infection being uncommon.