Researchers in China have discovered that individuals who put on glasses look like at decrease threat of catching COVID-19. The authors of the research, printed in JAMA Ophthalmology, seen that for the reason that coronavirus outbreak in Wuhan in December 2019, few sufferers with spectacles had been admitted to hospital affected by COVID-19. To analyze additional, they collected knowledge on the carrying of glasses from all sufferers with COVID-19 as a part of their medical historical past.
Their small research discovered that solely 16 (5.8%) of the 276 sufferers admitted with COVID-19 wore glasses for greater than eight hours a day. As they decided that each one these sufferers had been short-sighted, they subsequent appeared up the proportion of individuals with myopia (short-sightedness) in Hubei Province, the place the hospital is situated. They discovered this to be a lot bigger (31.5%), indicating that the proportion of short-sighted COVID-19 hospital admissions was over 5 instances decrease than is perhaps anticipated from that inhabitants.
It is a fascinating statement, however as with all single research the outcomes should be handled with warning. Whereas eye safety has all the time been an necessary element of private protecting tools (PPE), the magnitude of distinction reported by this research raises suspicion. This isn’t to say that the outcomes might not be actual, however somewhat that we shouldn’t begin advising large-scale behavioural modifications (equivalent to carrying goggles alongside our face masks) till they’ve been independently confirmed.
Are eyes a window for the virus?
One of many key steps for any viral an infection is the preliminary entry into the physique. Whereas most of our physique is roofed with protecting pores and skin, which may be very efficient at stopping viruses or micro organism crossing into our physique, far thinner “membranes” cowl our airways, digestive system and eyes. The position of those thinner membranes is to permit exterior issues equivalent to oxygen, meals, and within the case of eyes, mild, into our our bodies. Sadly, viruses have discovered to make the most of these entry factors.
That is the rationale PPE is designed to guard these entry factors, via using face masks, goggles and protecting clothes. Nevertheless, whereas we would think about that the primary assault on these areas comes from viral particles transmitted via the air as aerosols, the primary manner that viral particles get to those weak factors is definitely through our palms. Therefore the COVID-19 recommendation to scrub our palms usually, for 20 seconds or extra, and keep away from touching our faces.
It due to this fact is sensible that overlaying our eyes with glasses might provide further safety, each from the virus which may be carried in different folks’s breath, but additionally in stopping wearers from touching their eyes. Certainly, way back to February there have been experiences of individuals catching COVID-19 by not suitably defending their eyes in healthcare settings. Additionally it is identified that comparable factors of entry into the physique (ACE-2 receptors) favoured by the coronavirus are additionally current within the eyes.
Ought to we begin carrying goggles?
A crucial a part of deciphering any proof coming from observational research is remembering that correlation (two issues taking place collectively) doesn’t essentially imply causation (one factor causes the opposite). To check for causation, a managed trial or check is now wanted.
Ideally, this might comply with two rigorously matched teams of individuals – some carrying glasses and a few not carrying glasses – to see which group will get contaminated extra usually. Proof from such a managed trial will all the time be far stronger than proof from an observational research equivalent to that within the current paper.
We should additionally notice that the authors of this research listed various weaknesses. It was a really small research at a single web site. The researchers’ knowledge for the overall inhabitants got here from a a lot earlier research on a pattern that was not precisely matched (by way of age, demography and different components) to their pattern admitted to hospital with COVID-19. They usually couldn’t assure that each one the folks with short-sightedness within the common inhabitants additionally wore glasses for greater than eight hours a day.
So though this new research may be very attention-grabbing, there are many causes to be cautious about this consequence. We definitely want extra knowledge earlier than any recommendation might be given about carrying goggles alongside our face masks.