Controversies in Modern Eye Care 2023: Myth busting in cosmetics

Laura Periman, MD, of the Periman Eye Institute in Seattle, Washington, presented, "Ocular toxins everywhere and in everything," during the 17th annual Controversies in Modern Eye Care symposium at the Skirball Cultural Center in Los Angeles, California.

This transcript has been edited for clarity.

Laura Periman, MD:

Hi, everybody, Laura Periman from Seattle, Washington. [It's] awesome to be here at the 2023 Controversies meeting here in Los Angeles. I was invited to give a talk about cosmetics, and I took the assignment of controversy seriously.

What are the controversies in cosmetics? We're told so many things; there's a lot of misinformation out there, but what does the science have to say about cosmetics and its impact on the ocular surface? So that's really what I focused on. I covered four different aspects of it, and I'll give you a brief view of a few of them.

Number one is prostaglandin analogs. We're all aware of the impact of prostaglandin analogs. and it turns out a lot of the over-the-counter eyelash gross terms are laced with prostaglandin analogs. The labels don't tell you what the concentration is, and many of these ingredients are more potent than travoprost. So I think there's an important call to action to request transparency from these over the counter cosmetics companies to reveal the concentration of isopropyl cloprostenate, which we all know is associated with prostaglandin analogue side effects.

The next thing I presented was particles. There's a lot of demonization around carbon black, but if you actually look at what the science says, there is a danger for inhaled carbon black. When you're talking about cosmetics at concentrations less than 10%, which is the maximum from the FDA cosmetics regulations, turns out there's no toxicity there. So the call to action there is to question everything that you're told. We're learning all the time, go to the science.

I also presented information about particles in our cosmetics, the nylon fibers and rayon fiber that are present in over the counter drugstore and other common mascaras are thought to potentially be detrimental to the ocular surface. There's case reports of the fibers lodging into the conjunctiva. When you look at these fibers under scanning electron microscopy, they have very sharp ends, and for the dry eye patient, I really recommend avoiding mascara formulations that have fibers in them, because if you don't have a sufficient tear film to flush those fibers away, that is a potential increased risk for lodging into the conjunctiva. We do have case reports of that.

I also talked about preservatives. Preservatives systems are so important—you don't want your mascara getting moldy, you don't want your lipstick getting moldy, you don't want any type of infectious material to colonize your mascara products or your other cosmetic products. So preservatives are critically important, they have a critically important role.

A couple of shout outs, things to watch out for: the cell culture data around formaldehyde donating preservatives is particularly compelling for being deleterious to the ocular surface health at concentrations of 0.05 parts per million—well below what you can smell with your nose—there's irritancy on the ocular surface.

Hydroxymethyl glycinate is a formaldehyde donating preservatives, it's important to know that the incident comes in contact with water, there's conversion into formaldehyde. It's a two way relationship of gas and solubility. As soon as formaldehyde becomes soluble, it is now formalin. So we do think that there's an impact on preservatives that are formaldehyde donating.

Next is parabens, we're taught that parabens are bad, but parabens are found in nature, they're found in blueberries. So when you look at the scientific data around parabens at low concentrations, there's no difference between controls in cell culture death. And these studies include very long contact times directly with meibomian gland stem cells, which isn't really translatable into an in-vivo situation. So parabens are used at low concentrations in cosmetics, and under low concentrations there's a no impact on cell culture survivability in some of these papers.

Phenoxy ethanol, another 'bad actor' [and] something to avoid, but it turns out it—at low concentrations—is not toxic to cell cultures. In fact, if you combine it with ethylhexylglycerin, which is a common one to preservative system in cosmetics, but phenoxyethanol and ethylhexylglycerin, you can lower the concentration of both, and at those low concentrations, you would not expect to see death in cell culture according to these published papers.

The last thing we talked about was phyto extracts. Now phyto extracts include things like tea tree oil. There's been some information about it that's created a wave of panic in our community, and that's not good for our dry eye patients who already have a high degree of anxiety. Turns out commercial preparations containing tea tree oil are often the 0.1-0.2% range commercially—well below what it takes to kill Demodex, you need 5% concentration for 15 minutes, but also that those low concentrations and commercial preparations, you can expect to see a nice reduction in the bacterial load associated with many of our dry eye disease patients, MGD patients, Demodex patients.

So that's just a brief overview of looking into some of the cosmetics controversies, some of the myth busting that we did today, and I just want to remind everybody that go to the science. If you're not sure, don't repeat what you heard. Go look for yourself. Read the papers and decide for yourself. Thanks for your time.