Sodium Hyaluronate (Blink / Aquify)

[neil0502]

Oy! Be Careful!!

I really have to dramatically limit my computer time (and no "paper reading"), but ... you can't stop looking into this stuff.

Here's what I found yesterday:

http://tinyurl.com/klbff

I'm not a chemist, though--right now--I wish I were, but ... the BLINK appears NOT to use a "phosphate buffer," but rather a "standard buffer." I'm interpreting this to mean that BLINK DOES NOT cause the calcification, though I will contact their manufacturer to verify this.

http://apps3.fao.org/jecfa/additive_...e/T0368e14.htm

Meanwhile, MY 0.5% Hyaluronic Acid drops DO, INDEED, use a "sodium phosphate buffer," so my doc has told me to cut way back rather than take any chances.

You can never relax with this dry eye (or, for that matter, any other chronic condition) issue....

I'll keep all posted.

Neil

[neil0502]

Susie-

Thanks for asking. I've been using both the HA drops and the castor oil drops since April 3rd. They both require refrigeration (no preservatives), so I can't just take them with me, but I've managed to use both about four or five times each day--always first thing in the morning and last thing at night.

Before the drops, every time I rode my bike (PanOptx glasses), I was having pretty severe problems ("gotta stay out of the contacts for a few days" type stuff). In the last week, I've ridden six times--granted, for shorter distances than I'd like--and had no major issues.

Ordinarily, my worst times are first thing in the morning and later in the evening. I've noticed that--since starting this regimen--a few minutes after I wake up, but before using the drops, I have some tears ... some actual tears ... that I can see (tear meniscus) pooling slightly above my lower eyelid.

I also found myself sort of strolling through the grocery store the other day, and--as most of you know--that's not a place to take your time.

I'm really being very careful not to either get overly optimistic, or to attribute with any certainty any improvement to the new set of drops (it's usually more complicated than that), but ... I actually think it's beginning to help

[SusieD]

Neil - how are you getting on with the drops you are using at the moment? are you finding you can apply them less?

[SusieD]

I have used a HA drop at 0.2% (preservative free - made in Italy) I cant honestly say it was any different to any other drop for me. It didnt feel as though it lasted any longer.

Will be interested to hear how you get on though Neil - particularly with the castor oil drops.

[neil0502]

maybe the good results of HA are form a higher consistency like 0.5% HA or 1%, but blink contacts is only 0.15% does this mean it wouldnt work as well? or it would but would take longer?

Here's the answer ... as best as I can piece it together:

The best source I found for help on the matter is below [1], where 0.1 and 0.3% were tested, but only as available in commercially-available products. Quoting: "the two SH-containing
treatments did not only differ in the concentration of this
viscoelastic. For example, the 0.1% SH drop was preserved
and isotonic with tears, whereas the 0.3% SH drop was preservative-free and relatively hypotonic. It is thus possible
that other properties may have accounted for the measured
differences in symptoms and NIBUT."

So it's a poorly controlled study. On the other hand, another study [2] used 0.4% HA and declared: "Hyaluronate eye drops are useful for treating severe dry eye in Sjögren's syndrome patients. The use of a formulation with pronounced hypotonicity showed better effects on corneoconjunctival epithelium than the isotonic solution."

Yet a third published report [3] declares that there is no difference in the effectiveness of HA based on it being "hypotonic" or "isotonic," so you should be able to conclude that--if the preserved/non-preserved thing wasn't the major confounding variable--that the strength of HA made the difference.

Lastly, a fourth study [4] (still with me?) showed that 0.1% HA "effectively improves the integrity of corneal superficial cells, as corneal epithelial barrier function is exerted mainly by the superficial layer of the epithelium."

The way I'm looking at it is this: HA seems to heal ocular surface damage pretty effectively. It also seems to increase tear evaporation time and subjective reports of patient comfort while staying on the eye for a good long while.

I'm more and more convinced that my dry eye was either caused, or made dramatically worse, by long-term use of benzalkonium chloride. If that's the case, then--from other research I've done--there really is damage, at the cellular level [4], that needs to be undone.

[1] http://www.springerlink.com/media/99...618705l659.pdf
[2] http://bjo.bmjjournals.com/cgi/conte...tract/86/8/879
[3] http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_docsum
[4] http://www.iovs.org/cgi/content/abstract/40/3/619

EDIT: Another link to a study showing that HA at 0.1% "show a significant clinical benefit in terms of relief of the symptom of burning when HA is applied topically to the eye three or four times per day or as required. HA also appears to have a protective effect on the corneal epithelium, as shown by a reduction in the level of staining of corneal epithelial cells by rose bengal. This study confirms that Fermavisc is a safe and effective product for use in the alleviation of symptoms of severe dry eye syndrome."

http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_DocSum

[sazy123]

maybe the good results of HA are form a higher consistency like 0.5% HA or 1%, but blink contacts is only 0.15% does this mean it wouldnt work as well? or it would but would take longer?

[neil0502]

That's great, Rebecca. I don't have a fax, but will see if I can use somebody else's....

As to this study: I received my drops yesterday. They compounded a 0.5% HA (instead of the 1% I was hoping for). I also ordered, and received, ophthalmic castor oil [1] hoping that it would provide the improvement to the lipid composition that this article seems to allude to

End of day one (though surely too soon to tell anything): my eyes were whiter than they'd been in recent memory. It's also raining here, so .... who knows.

I'll stick with this regimen for a while. I do think the HA has a lot of promise and no known down side.

[1] http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract

[Rebecca Petris]

Neil re HA you should see the study in Jan Cornea http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract. I read this too long ago to remember the details clearly but I was leafing through the issue for our newsletter update and thought this quote would interest you:

"Lack of surface activity for HA is inconsistent with the concept that it can be used to enhance tear film stability and is used as a therapeutic agent for dry eyes. However, HA has specific affinity for ocular mucins and proteins, and it may be that HA contributes to the surface activity of tears when complexed with ocular mucin or with other tear components such as proteins or lipids."

It contains several other HA refs - can fax them to you or something if you're interested.

[neil0502]

'nother good one:

http://www.bioiberica.com/publicaciones/pdf/glyco09.pdf

The aim of dry eye treatment is to increase the
precorneal tear film stability. Tear substitutes are
the most frequent medication for dry eye patients,
who request life-long treatment. Therefore, it was
estimated the influence of tear substitutes on the
precorneal tear film stability. The influence of
unpreserved artificial tear substitute containing
0.1% sodium hyaluronate (Healon 0.1%) was
compared with that of 7 different available tear
substitute preparations containing preservatives.
The results of the present study show that Healon
0.1% has the best influence on the precorneal tear
film stability. These data were found to be independent
of the viscosity property of Healon 0.1%.

Avisar R; Creter D; Levinsky H; Savir H. "Comparative study
of tear substitutes and their immediate effect on the precorneal
tear film". Isr J Med Sci 1997 Mar;33(3):194-7

[sazy123]

Thanks for bringing this to my atention, ill start using it again see if it helps. Wouldn't it be ironic if the thing that helps is the thing i could actualy get in the first place. lol

[neil0502]

From the research I've done ... and it's a bunch ... Hyaluronic Acid is an exceptionally promising option. Vismed has a slightly higher concentration of HA than does Blink, though possibly not enough higher to make much difference.

Nonetheless, if you Google "hyaluronic acid" and "dry eye," you'll find significant test data showing that HA does a wonderful job of helping to speed corneal epithelial healing, and protecting the eye against cytotoxicity (cell damage) caused by things like preservative.

It has nothing but upside, as far as anybody knows. If Blink (or Vismed or Aquify) are all you have access to, they're probably an excellent choice for long term use.

Some links worth looking at:

http://bjo.bmjjournals.com/cgi/content/full/88/6/821

http://www.iovs.org/cgi/content/abstract/34/7/2313

http://www.iovs.org/cgi/content/full/43/11/3409

EDIT: here's another good one....

http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_docsum

[sazy123]

Umm this is just another artifial tear, the same thing that is in Blink contacts?, i used it for a bit, didnt notice anything spectacular, is there a higher concentration of Hyaluronic Acid in visimed than in blink contacts or something?

If the we have i doubt its ground breaking stuff

[neil0502]

Vismed is coming to us Yanks....

For those keeping score in the States ...

http://carolinanewswire.com/news/New...e&id=3795&op=t

http://www.lantibio.com/about.htm

A North Carolina company (1-21-2006) acquired the rights to market VISMED in the States.

"Lantibio expects to commence late stage clinical studies with VISMED(R) in 2006."

Research on Hyaluronic Acid for Dry Eye looks hugely promising (IMO). No known ocular side effects.

These same Lantibio folks are also working on "Moli1901"

http://www.lantibio.com/phase2_dev_moli1901.htm

Cool stuff....

[markL]

I can't seem to find them in the US or even on US based sites on the Internet.
The only pace I could find VISMED is at:
http://www.westons.com/ which is in the Uk.
It would cost me about $25 for 20 (given shipping).

Unless someone knows a place I can source these in the US, I will place my order at Westcon and let everyone know how it goes.

Oh the irony of it. someone from the US having to order something from the UK. www.contact-lens-direct.co.uk also stock Vismed. and see
http://www.trbchemedica.com/ANG/VISM...scribInfo.html for info on vismed. If you want to order some tea bags while your at it I can recommend PG tips.

[neil0502]

FYI:

Aquify has 0.10% Sodium Hyaluronate while Blink has 0.15%. Vismed (UK) is 0.18%.

My doc tends to think more is better and is, in fact, going to try to find a way for me to try the surgical version of Sodium Hyaluronate (1.0 - 3.0%) ... if possible.

This is my primary care ophthalmologist. I go back to the corneal guy in two weeks. If I learn anything new there, I'll surely post.

I want to move to Colorado ... and I'm not very amenable to my eyes being the reason that I can't!