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Are you worried about preservatives?

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  • Are you worried about preservatives?

    I wanted to take a little time to explain in more detail where I stand on “the preservative issue”, above and beyond what's posted on the preservatives page. This is in part to address some confusion and concerns that have arisen as a result of recent discussions about preservatives, and in part to explain why as moderator I may sometimes find it necessary to object to dogmatic statements about the use of preservatives or, well, about any other dry eye topic where medical and lay opinions clearly span a wide range.

    I've heard preservatives are toxic. So, should I avoid them altogether?

    It’s easy enough to say “Preservatives are toxic”. It is not necessarily easy for all of us to figure out what that really means or what to do with it in practice.

    Of course all preservatives have some degree of toxicity. No surprise that studies show this. That’s the whole point of a preservative – if it ain’t toxic, it won’t kill bugs. As with all drugs, there is no free lunch. This is also true with any Rx or OTC systemic or topical drugs we take for dry eye. The risks and benefits can to an extent be discussed in generic terms but at the end of the day they often have to be weighed in our unique circumstances.

    I believe that it is important that we all be aware of the potential for dry eye to be exacerbated by frequent exposure to eyedrop preservatives, be they known harsh preservatives like BAK or milder ones like sodium perborate, purite or polyquad. It should also be clear that the fact that a preservative is described as "disappearing" or "preservative free in the eye" does not exempt it from concern.

    The actual risk, i.e. not "Is it toxic?" but "Will it harm ME?" depends on many factors such as the toxicity of the specific preservative; frequency of exposure; quality of existing tear film; length of use; and of course individual sensitivities.

    So while awareness is important, I believe that simply waving a “no-preservatives” wand at this situation belies its complexity, the potential tradeoffs involved, and the right and responsibility of the individual (to say nothing of his/her doctor) to weigh the tradeoffs and make treatment decisions accordingly.

    Consider the host of challenges we face in seeking over-the-counter lubricants:

    1) Almost all people with chronic, moderate to severe dry eye require lubricants and many require frequent use of lubricants.

    2) There’s a ton of lubricants on the market. Most of them make pretty extravagant claims for themselves and it’s difficult to sort fact from hype.

    3) There are conflicting views in the medical community about what makes a lubricant effective.

    4) There’s some crummy or at any rate questionable preservatives out there in OTC eye lubricants, although thankfully BAK has been eliminated in most.

    5) There’s a very limited selection of preservative-free products.

    6) Many people cannot get relief with any unpreserved lubricants currently on the market.

    7) It’s nigh impossible to separate a product from its preservative: If someone’s experiencing poor results, is it because the product is ineffective or because the toxicity of the preservative is out-shouting the effectivenss of the lubricant?

    This is a very difficult reality for us to deal with.

    If you can manage fine with unpreserved tears, great. More power to you. I only wish it were true of ALL of us, then we wouldn’t even have to talk about it.

    But it must be recognized that there are those (I’m raising my hand…) who don’t, can’t, or won’t manage with unpreserved tears! And in a community like this, I daresay it’s a fairly significant proportion.

    We have to find a balance between safety with efficacy. We can argue all day about which is the dog and which is the tail, but at the end of the day, if we sacrifice too much of one or the other, we’re going to have problems.

    What’s better, an unpreserved product that wets too poorly to provide any meaningful protection, or a product with a mild preservative that wets well and provides relief but may have more toxicity? Unpreserved drops used 2ce an hour, or preserved drops used once every 4 hours? There’s no obvious answers to these questions. Some say it's easy: use viscous unpreserved tears. The viscosity theory (“thick stuff lasts longer”) may sound logical, but it’s simply not borne out in practice for all of us, and even if it were, I wouldn't need all the fingers of one hand to count the viscous unpreserved products actually on the market.

    So what should I do?

    Probably what you're already doing: use your common sense, keep an open mind, and keep talking to your doctor. Keep looking till you find something effective. Maybe what you find helps keep you well enough protected at night that you stay erosion free. Maybe what you find does not have to be used as frequently as whatever other type of product you were using. Maybe with your particular “brand” of dry eye, too frequent lubrication was at least as much of the problem as the (in)efficacy of the drop. Maybe this, maybe that, maybe the other. See your doctor regularly and talk to him/her about all the pros and cons of the various products. And, importantly, make sure you are exploring all possible non eyedrop forms of protection and pain relief - punctal occlusion, MGD treatments, protective eyewear, humidification, etc. No eyedrop should be expected to do it all.

    When I hear someone is benefiting physiologically (and as a result in many cases emotionally) from a preserved eyedrop, and that their doctor is in favor of this, well, I may mention preservative risks but I'll be cautious about the manner of stating or implying something is likely to harm them which, after all, is different than simply being toxic.

    I have declined to participate in aggressive anti preservative campaigning on this board because I don't want to be in a position of trying to persuade people that what their doctor sanctions may in fact be dangerous and I have objected to such campaigning taking place here because I do not want vulnerable patients frightened by dogmatic claims about treatments harming their eyes to the point that they become hopeless. I think that the responsible way to influence people is by flagging possibilities and sending them back to their doctor with questions.

    One of my strong principles for this board is, I don't want people to use it as a substitute for medical advice. We need professionals who can monitor us with some objectivity and we need them to help us evaluate the short and long term tradeoffs of any treatments.

    Conflict of interest disclosure

    As (hopefully) most of you know, in addition to running Dry Eye Talk, I wrote The Dry Eye Zone and I run The Dry Eye Shop. Some of you may be wondering “If she weren’t selling Dr. Holly’s Drops, would she be taking a hard line on all preservatives?”

    Fair enough. I suppose for all of us, our views are going to be colored in some degree by our personal experience. I can only say that when I took the drops over, I had a choice about going with a preserved or unpreserved version and opted for preserved in full confidence of its safety and efficacy. Beyond that... I’m sorry, but there are no shortcuts here. I can defend myself till I’m blue in the face and it would be a waste of breath. If you really want to know, you’ll have to just read this site and my posts and decide for yourself whether I have credibility, integrity and humility enough that my opinions can be taken as honest opinions. If you have any specific questions or concerns, please, don't hesitate to email me or even give me a call.

    If you are interested in knowing how I got involved with the eyedrops, please click here. You can also read more about my preservative views at this link and a little about the specific preserative at this link.

    I, and my best dry eye buddies, used Dr. Holly's drops daily for years before I ever considered of taking over distribution of them. Can I write a technical treatise about the preservative used exclusively in Dr. Holly’s drops? Nope. Am I a believer in its safety? Yup. Are those drops a miracle elixir for everyone? Nope. But if those drops weren’t effective AND safe, I wouldn’t be here writing this, because I still wouldn’t be able to see and still wouldn’t be able to wear special lenses that let me see. I am an ardent and unapologetic fan.
    Rebecca Petris
    The Dry Eye Foundation