Suddenly out of nowhere the most pressing issue in the contact lens industry is per and polyfluoroalkyl substances (PFAS). PFAS are fluorinated substances that contain at least one fully fluorinated methyl or methylene carbon atom with a few exceptions.1 PFAS, Chlorinated polyfluorinated ether sulfonate (PFOS), Perfluorooctanoic Acid (PFOA) and other fluorinated substances in the class are commonly described as persistent organic pollutants or “forever chemicals” because they remain in the environment for long periods of time.2

Residues of these fluorinated substances have been detected in humans and wildlife, prompting concern about impacts to health.3,4,5 According to the National Academies of Sciences, Engineering, and Medicine, PFAS exposure is linked to increased risk of dyslipidemia (abnormally high cholesterol), suboptimal antibody response, reduced infant and fetal growth, and higher rates of kidney cancer.6

Historically, alarm bells have been raised about forever chemicals; in relation to carbon tetrachloride as a dry-cleaning solvent in the 50’s-60’s, DDT and chlorinated bi phenyls in the 80’s for transformer fluids. General Electric litigated with EPA about cleaning up the Hudson River bed for decades. Now PFAs are front-and-center in the news as a potentially dangerous forever chemical once more.  

So, what’s the real story? I connected with Dr. Lawrence Chapoy. Dr Chapoy received a PhD in chemistry from Princeton University and served as former VP of R&D at Wesley Jessen Vision Corporation. He is currently owner of HPM Company, a plastics consulting company. Prior to his contact lens experience, Dr Chapoy worked at the Italo-American fluorine chemical producer Ausimont/Montefluos.  Dr, Chapoy states “cytotoxicity (from PFA’s) generally stops at a few parts per million (PPM). Endocrine toxins, however, stop at a much lower level, in the parts per billion range and thus are more insidious. While generally we know PFAs are very stable, the actual risks are largely unknown as are the levels at which risk is incurred”.

Dr Chapoy emphasized the importance of starting with facts before jumping to conclusions. “First, it appears the original article was published by a professor from NC state, not by the Environmental Protection Agency (EPA) or Centers for Disease Control (CDC). While the article mentioned that their measurements came from an EPA certified lab, all that means is that the lab follows Good Laboratory Practice, GLP, and other procedures required by EPA. For example, that the lab’s instruments are calibrated when needed and the lab is compliant with the requirements and regulations including maintaining a paper trail of the procedures they follow with the EPA. The data itself is not certified or reviewed by EPA”.

Dr. Chapoy goes on to state “the study indicates that PFA was measured in the blood from a number of contact lens wearers. As PFAs are ubiquitous in society and absorbed from a number of products we ingest or wear, the data in contact lens wearers means nothing without having a control group of people who have never worn contact lenses to measure against”. The control group would be necessary to determine a difference between a group who wore contact lenses and one who didn’t, otherwise how would anyone be able to tell if the source of the increased PFA measurements were contact lenses or something else? Also, PFAs are theoretically only in silicon hydrogel contact lenses, not classic hydrogels, so a better control group might be people who are contact lens wearers who have worn hydrogel lenses only compared to those who have worn silicon hydrogel or silicon-based gas permeable contact lenses. 

Dr Chapoy also mentioned that the article states that organic fluorine is a marker for PFAS, however there are perfluoro alkanes, perfluoro ethers, per fluoro acids that are also ubiquitous in our society. Things like Teflon, refrigerants and others have been around for decades. Refrigerants have been studied extensively during the ozone hole scare of the 1970’s. None of this came out then so why now?

Our current knowledge related to the products we prescribe day-to-day is from a Vmail story published on May 18. The article included responses received from queries to CooperVision, Alcon and Bausch & Lomb on the topic. CooperVision responded “(PFAS) may be used in a wide range of products for important chemical and physical properties“. Alcon responded “Dailies Total1 and Total30 contact lenses do not contain organic fluorine in their formulation” and Bausch & Lomb responded “no Bausch + Lomb soft contact lenses are formulated with fluorinated polymers or PFAS.” A spokesperson from Bausch & Lomb I reached out to reiterated their lenses are “not formulated with fluorinated polymers or PFAS.”

Dr Chapoy suggests it might be important for our industry to assemble a technical fact-finding panel to get to the bottom of this issue so we can determine the facts and get to the root-cause of the problem without rhetoric or potentially harming the business of companies who serve our industry and patients. This sounds like a sober, rational and responsible way to discuss this issue. 

References

  1. www.researchgate.net
  2. PERSISTENT ORGANIC POLLUTANTS, L. Ritter, K.R. Solomon, J. Forget , Canadian Network of Toxicology Centres, Guelph ON
  3. Houde M, Martin JW, Letcher RJ, Solomon KR, Muir DC (2006). “Supporting Information” (PDF). Environmental Science & Technology. 40 (11): 3463–3473. Archived from the original (PDF) on 14 October 2019
  4. ^“Per- and Polyfluorinated Substances (PFAS) Factsheet”. National Biomonitoring Program. Centers for Disease Control and Prevention. 2 September 2021. Retrieved 10 October 2021.
  5. Elton, Charlotte (24 February 2023). “‘Frightening’ scale of Europe’s forever chemical pollution revealed”. euronews. Retrieved 25 February 2023
  6. www.nationalacademies.org