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Comment by jaggederest | Hacker News Reader

It's a very interesting drug. There are a lot of concerns right now around PFAS in water supplies, for example, and Miebo/Evotears are pure PFAS (perfluorohexyloctane) that's instilled directly in the eye, giving you a dose somewhere around a million times higher than levels of concern in drinking water.

But it is absolutely revolutionary if you have dry eyes. Quotes include "I feel like my eye is actually too wet now"

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It's also used to replace the intraocular fluid. In that case you'll get trillions times that.

This is why the PFAS scare is quite a bit silly. "PFAS" is such a broad category that it's ridiculous.

Surely the sheer number and amount of different PFAs being distributed around the planet without knowing about long term effects is the ridiculous bit. The argument that because we dump a lot of it must mean that it's safe is just wishful thinking. Remember when lead was added to fuel and large amounts of lead were then pumped into the air? It had very noticeable effects on criminality in people.

The question is in the amount of them. PFOA and PFOS were literally dumped in kiloton quantities into the environment without much thought about their toxicity. They were used in firefighting foam that was just flushed into the sewer.

So yeah, removing that source of pollution is good. At the same time, the effects of even the worst offender (PFOS) are at most mild. Wildlife and epidemiological studies found significant effects only in areas that are at least billions of times more contaminated with PFAS than can ever accumulate in the environment if the waste streams are managed properly.

What the fuck... what's stopping this from poisoning our water supply?

The absolute miniscule volume

Pfas are measured in ppb or even ppt

And water supply is measured in km^3

so 1 liter of eye drop per 1ppt of km^3

That would be 1 liter of the active ingredient, not 1 liter of the eye drop. Also I don't believe that 1 ppt of this stuff is harmful when people are putting it directly in their eyes without severe harm.

There's only a single ingredient, these eyedrops are 100% pure PFAS

And people put asbestos on their christmas trees back in the day - I don't think "obvious harm" is a high enough standard.

I think obvious harm at 1 trillion parts per trillion is a pretty good standard to meet if you want to claim harm at 1 part per trillion.

It's most definitely going to accumulate inside the body, although slowly.

Yes, but too slowly to matter. Average person consumes 1.5 liters per day of water, so if you live to 100 that's 55000 liters. At 1 ppt that's 1 ng / liter, or 55 ug over a lifetime. That's multiple orders of magnitude less than one drop of the stuff to your eye.

We will know after the drops have been out for over a decade, and actual real-world safety data studies get published.

Meanwhile, Restasis (cyclosporine A) (or a generic) works well, and doesn't have to be applied all day long, just two or three times a day. It does burn the eye initially, but it's not harmful, and the burning goes slowly away over time. It does take a few months to start working.

Maybe, maybe not, maybe like teflon, the real poison is an intermediate ingredient, but I think its bullshit that we're just creating chemicals that linger in our water supply for eternity. You literally cannot find anyone in America without traces of the dangerous variant of the PFAS in their blood stream. Like every sip of water is some ridiculous dupont cocktail and we have to tolerate it because people have dry eyes and want non stick pans. Why cant you just use theratears?

> You literally cannot find anyone in America without traces of the dangerous variant of the PFAS in their blood stream.

You also can't find anybody in the world without traces of lead, arsenic, uranium, radium, and other chemical elements in their blood.

> Why cant you just use theratears?

Because they don't work.

Good thing there are 3*10^21 atoms of H2O in a water drop

Ok and there are around that many atoms of pfas per tear drop?

PFAS are expressed as a mass fraction, not mole fraction.

How many gallons of Miebo/Evotears do you think are manufactured every year?

Multiply that by the t in ppt. How many trillions of gallons of water do you think an average city uses every year?

Is all the Miebo/Evotears that’s manufactured being dumped directly into the drinking water supply?

How do you think pfas got into the water supply in the first place.

Largely firefighting foams, industrial and manufacturing, and landfill sources, but it's still an interesting problem. They don't really break down (that's why they're so useful both in a materials science sense and as a medication) which implies they'll stick around for an extremely long time.

Where do you think it goes after it gets to your eyes? The valid choices are:

A. Absorbed into your body forever.

B. Becomes a part of the water cycle.

C. Is broken down.

And even choice A eventually becomes choice B, ideally after significant time though.

One thing you can be sure of is that the vats of PFAS being produced year after year for this drug aren't going away anytime soon. They're called "forever chemicals" for a reason.

Being dispersed in the environment is not the same as being concentrated into our drinking water supply with each measure resulting in 1ppt contamination of a trillion measures of water.

I suggest that you read about food chains and water cycles.

Teflon is also PFAS. The whole PFAS scare is overblown.

> The whole PFAS scare is overblown.

You have absolutely no idea of what you're talking about. If you actually think the scare is overblown, I dare you to drink the whole bottle of that eyedrop.

> You have absolutely no idea of what you're talking about.

I do.

1. "PFAS" is a technically incorrect term. 2. It's ridiculously broad. Teflon is PFAS, sevoflurane is PFAS, and so on.

> If you actually think the scare is overblown, I dare you to drink the whole bottle of that eyedrop.

They literally use the same liquid to FILL THE EYEBALLS after retinal surgery. It's been approved for 25 years. A bottle of eyedrops has 4 milliliters of it, and it would do essentially nothing if swallowed.

The only relevant subdivision of PFAS is by chain length: small, medium, large. Even so, they all accumulate in the environment. Just because you with your short term selfish interest doesn't take any responsibility for the world at large, willing to totally destroy it for small personal gain, does not mean that others don't either. All PFAS are very harmful in the environment because it's like paperclips that keep being made but not ever being unmade. Medium and long chain are also harmful in the human body due to significant accumulation.

Teflon does not get a free pass. It is a toxin. The last I recall, it causes brain damage in children. There is a reason why sane people avoid nonstick cookware.

> The only relevant subdivision of PFAS is by chain length: small, medium, large.

PFOA and PFOS have 8-member fluorinated chains. And they are dangerous, with clear dose-dependent effects.

PFHO has a 6-member fluorinated chain, and it has no known toxic effects.

> Even so, they all accumulate in the environment.

So does silicon oxide. Or a lot of other "terminal" compounds. The questions that need to be asked are:

1. Are they dangerous by themselves?

2. Do they bioaccumulate?

3. Do they stay mobile in the environment (i.e. don't get sequestered)?

In case of PFHO, it's not dangerous. It does not bioaccumulate because of its poor absorption. And it's also not mobile.

> The last I recall, it causes brain damage in children.

No, it doesn't.

Don't confuse silicon oxide with a PFAS. It is quite the negligent and hazardous fallacy to put them in the same bucket. One has been around for billions of years. The other hardly has any research, and will take at least a decade more of data and research before we know what's it is capable of.

You are in no way smart enough to understand and consider all the pathways, uptake mechanisms, and consequences that are affected by the PFAS compound across all of biological life. Knowing just one or two over just a few years does not make you competent in it or qualified to make a broad safety comment.

The same argument applies to literally everything, including doing nothing.

PFAS is to my knowledge the only human-created unnatural class of compounds that does not deteriorate in the environment. So no, the argument applies exclusively to PFAS.

Instead of putting and accumulating PFAS in your body, just get punctal cauterization. No drops will be needed thereafter.

I have punctal plugs. They helped quite a bit, but for most people with dry eyes it's the lack of the lipid layer that is causing problems. Not the lack of water.

Punctual plugs are not as great as cauterization for multiple reasons. Firstly, plugs keep dropping off and getting lost over time. Secondly, they probably won't seal the gap fully.

The lipid emission will heal partially if one supplements vitamin A (10k IU) softgel, omega-3 triglyceride ester, taurine, and at least 4K IU of vitamin D3. It will heal enough to work. The D3 in this dose is for freezing autoimmune degeneration.

I have severe dry eye and I never need any drops except if I am wearing contact lenses.

Before committing to plugs, I tried temporary plugs made of (essentially) collagen. They completely seal the tear ducts, and they were just as effective as my current plugs. And my plugs have been in place for 10 years so far.

> The lipid emission will heal partially if one supplements vitamin A (10k IU) softgel, omega-3 triglyceride ester, taurine, and at least 4K IU of vitamin D3. It will heal enough to work.

Omega-3 acids help a tiny bit, and I'm getting D3 and A from multivitamins. And I'm doing all other recommended stuff: eyelid washing, compresses, IPL, etc. Over the years, I tried discontinuing all of that a few times, and my symptoms worsened as a result. But not by much.

PFHO is the most effective "artificial tears" type product. Nothing comes close to it.

> PFHO

Here we go again with the PFAS. It is the stuff to prefer the least, not the most.

> I'm getting D3 and A from multivitamins

That fails completely because they almost always don't have softgel oil-dissolve forms or the right dose at all. They're generally very far from it. It is exactly what leads to the autoimmune issue of dry eyes in the first place.

Yeah, yeah. Sure.

> That fails completely because they almost always don't have softgel oil-dissolve forms or the right dose at all

I tried tons of forms. My current ones are gel-filled capsules. Rather large ones, at that.

Sorry, but there's a huge amount of scholarly literature on this question. I've read tons of it over the years, and there is NO magical supplement that does anything but mildly improve the situation.

Forms alone won't accomplish anything if the dose isn't correct. With regard to vitamin A, some people confuse it with beta carotene, with the latter not working so well for this effect. Vitamin A even has evidence backing it as per PMC6462169. It does take a few weeks to begin to work. Even mild improvements stack up. It may not eliminate the need for an additional intervention, but it can mean the difference between whether the additional intervention will work or fail.

Again, I read that and tried various forms.

Yes, they do help a bit. No, they don't help a lot. The study you cited find only a weak effect on some endpoints.

Same for fish oil and various omega-3 acids. The effects are either weak or in some cases non-existent ( https://www.nejm.org/doi/full/10.1056/NEJMoa1709691 ).

It is together that things work better. It is silly to look only at an individual effect.

You could try this:

Visomitin (Emoxipine/Mexidol) eye drops are a Russian-developed antioxidant medication known for treating dry eyes, fatigue, radiation damage, and improving vision, working to protect eye cells from damage (oxidative stress), but it's not widely available or FDA-approved in the US, requiring international purchase or specific prescriptions, often used for cataracts or post-surgery recovery, focusing on cell protection rather than just lubrication like many Western OTC drops.

> Visomitin (Emoxipine/Mexidol) eye drops are a Russian-developed antioxidant medication known for treating dry eyes, fatigue, radiation damage, and improving vision

I wouldn't recommend it. A quick search shows that it's not proven to do anything at all but it's also advertised as being the cure for parkinson's, asthma, back pain, high cholesterol levels, anxiety, blood clots, glaucoma, and Huntington’s disease while also making you smarter and improving your memory. This sounds like classic snake oil. Something I'd expect to see being sold alongside Horny Goat Weed and kratom at a gas station rather than an actual medication dispensed by a pharmacist. As fucked up as the American healthcare system is I guess you really have to hand it to Russia sometimes.

I wouldn't be too sure or cocky because it does have a very broad mechanism of action that does cast a wide net. Humility is warranted.

I'd happily be proved wrong, but all the usual red flags are there. About the best that can be said for it at the moment is that there doesn't seem any more evidence that it's harmful than there is for it being helpful. Hopefully it gets the research to back up the claims. It certainly purports to be effective for conditions there's plenty of interest in developing effective and safe treatments for so you'd think that nations around the globe would be eager to look into it.

The West and the globe doesn't work that way. There is little to no money in something that can't be patented. For this reason, at least no pharma firm will pay for any trials with it, and so it can't easily ever get FDA approved. Naivete does not help.

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