09-18-2020, 08:01 AM
...says so in a massive study of 276 people in Wuhan.
https://thehill.com/policy/healthcare/51...irus-study
https://thehill.com/policy/healthcare/51...irus-study
Audaces fortuna iuvat
Apparently eyeglasses work to block COVID...
Audaces fortuna iuvat
...says so in a massive study of 276 people in Wuhan.
https://thehill.com/policy/healthcare/51...irus-study
https://thehill.com/policy/healthcare/51...irus-study
Audaces fortuna iuvat
10-03-2020, 08:03 PM
(09-18-2020, 08:01 AM)Mick Wrote: ...says so in a massive study of 276 people in Wuhan.
https://thehill.com/policy/healthcare/51...irus-study
The actual study report can be seen at
https://jamanetwork.com/journals/jamaoph...le/2770872
The study is small as it is just the patients at a particular China hospital from January to March. Remember, in China, if you had a fever, you got tested. If you tested positive, you were admitted to a hospital. So this is basically a group of cases that were symptomatic in the community.
I have some question about whether their 31.5% percentage of people that wear glasses in their community is accurate. The description of the much earlier study on the number of people with glasses seems to indicate it applied to more or less the same population some 20 or so years earlier. Note that increased use of contacts or eye surgery to correct myopia might have changed those numbers. They also refer to (but don't use) another survey that 80% of the China population has myopia. The 80% and 31.5% numbers seem pretty far apart to me.
In those early days, they noticed that those with COVID included fewer people with glasses than the general population. So, they started a study which included asking about vision history and wearing glasses as part of taking a patient's medical history.
The significance of myopia is that most people with myopia wear glasses all day (in particular, during times when they might be exposed to others). However, their data is dependent on the question of whether the patient wears glasses more than 8 hours a day. In this study, the people that used glasses 8hrs/day were exactly the group with glasses that had myopia.
I don't know why it took so long for this data to get out. The effect seem pretty strong, even if the study is relatively small. In their cohort, if you have 100 cases, you'd expect roughly 31 to wear glasses. But in their data, only about 6 did. (95% CI 3.0% - 8.6%) I think the raw numbers are too small, but, wow, that's a big difference. If this is a real effect and anywhere near a 5x reduction in infections, I'd think this is a significant factor.
Some group such as Santa Clara County could get this amount of data in two days worth of cases. A week or a month of data would really tighten this up quite a bit. If only someone would ask.
In the Chinese study, NONE of the 300+ patients wore contact lenses or had refractive surgery. Since I don't know how common those are in China, I don't know if that is something of interest or concern about the study. It's one thing to think of lenses as reducing exposure to infectious droplets or aerosol, but it's another to think of how contact lens usage might impact infections.
I don't want to suggest that wearing glasses could possibly be better than wearing a mask, but if it were to reduce the risk of infection by a factor of 5, I suspect a lot of people might start wearing glasses. It seems collecting the data to evaluate such a hypothesis should be pretty easy. Need 1000 cases, or 10,000 cases? It should be easy to get. I doubt the fact that you wear glasses is covered by HIPAA, since it as plain as ....
My feeling is that the effect of wearing glasses may be more accurately measured than the effect of wearing masks. If it turns out that wearing glasses reduces infection rates by 5x, do you think the CDC might eventually recommend doing so in a few years?
There is an "Invited Commentary" attached to the article that seems like what the CDC might write. It warns of the issues with a single observational study, and that association is not causality. Gee, if the effect was only a 10% reduction, do you think they would have invited such a commentary?
From reference.com regarding the US:
Quote:More than 50 percent of all women wear glasses and 18 percent wear contact lenses. Among men, 42 percent wear glasses and another 14 percent wear contacts. Those people who wear both forms of corrective lenses wear contact lenses more often. About 30 percent of the U.S. population is nearsighted, and 60 percent is farsighted.
Full disclosure: I wear glasses.
(09-18-2020, 08:01 AM)Mick Wrote: ...says so in a massive study of 276 people in Wuhan.
https://thehill.com/policy/healthcare/51...irus-study
The actual study report can be seen at
https://jamanetwork.com/journals/jamaoph...le/2770872
The study is small as it is just the patients at a particular China hospital from January to March. Remember, in China, if you had a fever, you got tested. If you tested positive, you were admitted to a hospital. So this is basically a group of cases that were symptomatic in the community.
I have some question about whether their 31.5% percentage of people that wear glasses in their community is accurate. The description of the much earlier study on the number of people with glasses seems to indicate it applied to more or less the same population some 20 or so years earlier. Note that increased use of contacts or eye surgery to correct myopia might have changed those numbers. They also refer to (but don't use) another survey that 80% of the China population has myopia. The 80% and 31.5% numbers seem pretty far apart to me.
In those early days, they noticed that those with COVID included fewer people with glasses than the general population. So, they started a study which included asking about vision history and wearing glasses as part of taking a patient's medical history.
The significance of myopia is that most people with myopia wear glasses all day (in particular, during times when they might be exposed to others). However, their data is dependent on the question of whether the patient wears glasses more than 8 hours a day. In this study, the people that used glasses 8hrs/day were exactly the group with glasses that had myopia.
I don't know why it took so long for this data to get out. The effect seem pretty strong, even if the study is relatively small. In their cohort, if you have 100 cases, you'd expect roughly 31 to wear glasses. But in their data, only about 6 did. (95% CI 3.0% - 8.6%) I think the raw numbers are too small, but, wow, that's a big difference. If this is a real effect and anywhere near a 5x reduction in infections, I'd think this is a significant factor.
Some group such as Santa Clara County could get this amount of data in two days worth of cases. A week or a month of data would really tighten this up quite a bit. If only someone would ask.
In the Chinese study, NONE of the 300+ patients wore contact lenses or had refractive surgery. Since I don't know how common those are in China, I don't know if that is something of interest or concern about the study. It's one thing to think of lenses as reducing exposure to infectious droplets or aerosol, but it's another to think of how contact lens usage might impact infections.
I don't want to suggest that wearing glasses could possibly be better than wearing a mask, but if it were to reduce the risk of infection by a factor of 5, I suspect a lot of people might start wearing glasses. It seems collecting the data to evaluate such a hypothesis should be pretty easy. Need 1000 cases, or 10,000 cases? It should be easy to get. I doubt the fact that you wear glasses is covered by HIPAA, since it as plain as ....
My feeling is that the effect of wearing glasses may be more accurately measured than the effect of wearing masks. If it turns out that wearing glasses reduces infection rates by 5x, do you think the CDC might eventually recommend doing so in a few years?
There is an "Invited Commentary" attached to the article that seems like what the CDC might write. It warns of the issues with a single observational study, and that association is not causality. Gee, if the effect was only a 10% reduction, do you think they would have invited such a commentary?
From reference.com regarding the US:
Quote:More than 50 percent of all women wear glasses and 18 percent wear contact lenses. Among men, 42 percent wear glasses and another 14 percent wear contacts. Those people who wear both forms of corrective lenses wear contact lenses more often. About 30 percent of the U.S. population is nearsighted, and 60 percent is farsighted.
Full disclosure: I wear glasses.
10-04-2020, 09:25 PM
There is an unpublished study out of India showing a large reduction in infections in ER physicians who wore masks plus face shields vs masks alone. Entry through the conjunctiva could be significant.
All physicians in the Alameda County clinic system where I now work are required to wear both for all patient contact.
All physicians in the Alameda County clinic system where I now work are required to wear both for all patient contact.
There is an unpublished study out of India showing a large reduction in infections in ER physicians who wore masks plus face shields vs masks alone. Entry through the conjunctiva could be significant.
All physicians in the Alameda County clinic system where I now work are required to wear both for all patient contact.
All physicians in the Alameda County clinic system where I now work are required to wear both for all patient contact.
10-05-2020, 07:57 AM
(This post was last modified: 10-05-2020, 08:07 AM by Hurlburt88.)
University of Iowa med school also really pushing combination of masks and shields. and my neighbor's COVID case was deemed most probably through the eyes (artisanal data)
DIE LUFT DER FREIHEIT WEHT
(This post was last modified: 10-05-2020, 08:07 AM by Hurlburt88.)
University of Iowa med school also really pushing combination of masks and shields. and my neighbor's COVID case was deemed most probably through the eyes (artisanal data)
DIE LUFT DER FREIHEIT WEHT
10-05-2020, 08:33 AM
I'm a little surprised, but the cost/benefit for wearing a face shield (or safety glasses) in a high-risk environment seems like a no-brainer. Hadn't realized the conjunctiva were vulnerable.
10-05-2020, 08:57 AM
Taiwan doctors have been wearing goggles since the outbreak.
And actually, back in late March/April, it was very hard to find any goggles on Amazon so there were at least some people that were anticipating this vulnerability.
And actually, back in late March/April, it was very hard to find any goggles on Amazon so there were at least some people that were anticipating this vulnerability.
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