Tweet
OK it looks like a well done study with important results.
But...
There are approximately a gajillion published studies on the sins of BAK against the cornea and beyond, and we have to kill more bunnies to re-prove it how many more times? Quit using the durned stuff already. It's not like we don't have other effective preservatives. Oh, and lest we forget, ever heard of preservative-free?
A new safety concern for glaucoma treatment demonstrated bymass spectrometry imaging of benzalkonium chloride distribution in the eye, an experimental study in rabbits.
We investigated in a rabbit model, the eye distribution of topically instilled benzalkonium_(BAK) chloride a commonly used preservative in eye drops using mass spectrometry imaging. Three groups of three New Zealand rabbits each were used: a control one without instillation, one receiving 0.01%BAK twice a day for 5 months and one with 0.2%BAK one drop a day for 1 month. After sacrifice, eyes were embedded and frozen in tragacanth gum. Serial cryosections were alternately deposited on glass slides for histological (hematoxylin-eosin staining) and immunohistological controls (CD45, RLA-DR and vimentin for inflammatory cell infiltration as well as vimentin for Müller glial cell activation) and ITO or stainless steel plates for MSI experiments using Matrix-assisted laser desorption ionization time-of-flight. The MSI results were confirmed by a round-robin study on several adjacent sections conducted in two different laboratories using different sample preparation methods, mass spectrometers and data analysis softwares. BAK was shown to penetrate healthy eyes even after a short duration and was not only detected on the ocular surface structures, but also in deeper tissues, especially in sensitive areas involved in glaucoma pathophysiology, such as the trabecular meshwork and the optic nerve areas, as confirmed by images with histological stainings. CD45-, RLA-DR- and vimentin-positive cells increased in treated eyes. Vimentin was found only in the inner layer of retina in normal eyes and increased in all retinal layers in treated eyes, confirming an activation response to a cell stress. This ocular toxicological study confirms the presence of BAK preservative in ocular surface structures as well as in deeper structures involved in glaucoma disease. The inflammatory cell infiltration and Müller glial cell activation confirmed the deleterious effect of BAK. Although these results were obtained in animals, they highlight the importance of the safety-first principle for the treatment of glaucoma patients.
Brignole-Baudouin F, Desbenoit N, Hamm G, Liang H, Both JP, Brunelle A, Fournier I, Guerineau V, Legouffe R, Stauber J, Touboul D, Wisztorski M, Salzet M, Laprevote O, Baudouin C.
It took more than five months for my eye to recover from the inflammation caused by the NSAID drug Nevanac (Nepafenac) preserved with BAK, prescribed pre- and post-operatively.
Yes, there is a preservative-free NSAID drug available for cataract surgery: Acular PF
At one year post-op, my eyes are still exquisitely sensitive to many common chemicals, including flourescein, and components in over the counter drops and solutions. I can only conclude this ongoing sensitivity is due to the damage caused by BAK since it began after the cataract operation.
Thanks to this forum, I know about BAK, and only too well understand the damage from this preservative in my surgeon's prescription. This surgeon was highly recommended, and is affiliated with one of the top eye hospitals in the US, the recipient of many awards, and is still in practice.
As long as there are practicing physicians who fail to keep up with current research, keep those BAK studies coming. We patients need to be informed!
For me, this experience has raised many concerns: Why aren't eye docs required to attend sessions on BAK as part of their continuing education? Why doesn't the FDA put black box warnings on BAK medications so patients might have a shot at avoiding this stuff? Why are BAK preserved drugs still on the market when there are safer substitutes? Why aren't pharmacists consulting with patients who come in with prescriptions for BAK-preserved medications? Baby boomers are just one demographic likely to have cataract surgery or other eye diseases like glaucoma; why aren't consumer oriented magazines like AARP writing about this issue so readers can be more informed?
This stuff is dangerous and I'm sorry to be "singing to the choir" here,