Hypotonic and Hypertonic Tears

[Francesco]

"what drops are hypotonic and what drops are hypertonic ?"

sazy123 intelligently asked this question time ago...i would be interested too.....since i just discovered that Refresh drops can create more damage instead of healing an Evaporative Dry Eye (since in this type of Dry Eye osmolarity increases and the tear becomes hypertonic..too salty). Surely Theratears are Hypotonic....

It's time to ask ourselfs .."Is this drop good for my case?" instead of "i like how this drop feels"

[Randal]

"what drops are hypotonic and what drops are hypertonic ?"

sazy123 intelligently asked this question time ago...i would be interested too.....since i just discovered that Refresh drops can create more damage instead of healing an Evaporative Dry Eye (since in this type of Dry Eye osmolarity increases and the tear becomes hypertonic..too salty). Surely Theratears are Hypotonic....

It's time to ask ourselfs .."Is this drop good for my case?" instead of "i like how this drop feels"

According to this page, http://www.theratears.com/how.aspx , TheraTears is hypotonic.

Randal

[Terri]

Francesco: The University of Michigan's Agingeye.net website has a good summary page on artificial tears. According to the info on the page, Thera Tears, Hypotears and Akwa Tears are hypotonic.

There's also a good thread here that says hypotonic tears might not be good if you have compromised barrier function (corneal damage that shows up as staining on an eye exam). I believe that's why Dr. Holly's drops are formulated with high oncotic pressure (hypertonic).

I agree with your point that it's time to ask if a particular formulation is good for an individual's case, as opposed to whether it feels soothing in the short term. For instance, I have corneal damage that I'm trying to heal, so I should probably use hypertonic drops until my eye exam shows no more staining. On the other hand, if I had evaporative dry eye without corneal damage, hypotonic drops might be best.

Thanks for bringing this up. Your post has started me thinking about taking a closer look at the oncotic pressure of the drops I'm using.

[stephgurl1986]

wow, I'm confused now. Dr G. said that you shouldn't use hypotonic drops more than once in an hour- but I use Thera Tears like every 10mins and that is the only way my eyes feel a bit better - so I can cause damage with that???

[Francesco]

stephgurl1986 ..i don't know maybe someone will answer you.

Yes...Terri...thanks...i wrote this on purpose...i think that starting from now every drop should clearly have written on the box or someplace "Hypotonic for Evaporative Dry Eye" ecc ...since every drop is not the same. Maybe someone on this forum will change drops after reading this

[why]

Guys This topic can potentially be eye saving for a lot of us..we need to define whats good for what !

I mean I have Sjogrens Dry Eye bad..(Schirmers 1 & 3) Im using Celluvisc
(Carmellose Sodium) every 30 mins then Thera Tears as my eyes start to sting with celluvisc.

What do we use for what condition...

This applies to all of us I guess..
How do I find out what drops are best for my condition...?

I mean my Ophthal says use whatever feels comfortable...now that seems plain wrong advice ! should I get a copy of my Ophthal's test report to see what is wrong first..?

For instance I wear sealed goggles glasses..and my left goggle lens fogs up worse than the right in places that like have air con.

I mean one eye might have a different drop requirement than the other..

Anyone direct us to the best drops options ?

Cheers

TIA
Merry rest of Xmas and a healthier New Year to all !

[liz56]

I wonder if it is more complicated.

When I was first prescribed the over-the-counter Muro 128 5% for my recurrent corneal erosions (rce's), I was told that they are hypertonic. My mom is a nurse, and she explained that hypertonic means a high saline content (which has a drying effect); isotonic means a neutral saline content; and hypotonic means a low saline content. That's all that those words mean. What Dr. Holly is working on looks a little different to me, because he is interested in what produces a high oncotic pressure relative to that which is in the stroma.

Here is a 1985 abstract of his that I found, which mentions Hypotears, and I bolded the sentence that I think complicates matters regarding an either-or approach to hyper- or hypotonic solutions:

1: J Ocul Pharmacol. 1985 Winter;1(4):327-36.
Related Articles, Links

Colloid osmotic pressure of artificial tears.

Holly FJ, Esquivel ED.

Department of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock.

While the total osmolality of the aqueous tears and tear substitutes has received much attention in the past few years, the colloidal osmolality or the oncotic pressure (which includes the Donnan effect), has received practically no attention except for one single foreign publication. The colloidal osmolality of tears is twentyfold less than that of the corneal stroma, which in turn is less than 1% of the total osmolality of an isotonic solution, i.e. the magnitude of the colloidal osmolality is only a few hundreths of a per cent of total osmolality. This may be the reason why its role was thought to be unimportant by many researchers. Despite its relatively small magnitude when compared to total osmotic pressure, the oncotic pressure has been shown to play a major role in the maintenance of the water balance of bodily tissues and has been used as a diagnostic parameter in alveolar edema. The same principle has been used to formulate a collyrium, Dehydrex, or dextran-containing storage media for excised corneas such as the Kaufman-McCarey medium that have a colloidal osmolality at least equal to that of deturgescent corneal stroma. Such formulations are able to dehydrate corneal stroma even in the total absence of epithelium. Dehydrex has been shown to have a beneficial effect on damaged epithelium and is thought to be the drug of choice for the treatment of recurrent epithelial erosion when other treatment modalities have failed. In the present study, the total osmolality and the oncotic pressure of several artificial tear preparations presently marketed was determined and compared with the oncotic pressure of tears and the corneal stroma. We have found that the oncotic pressure of HypoTears is nearly sixty times higher than that of the leading artificial tear, thus it is comparable to the oncotic pressure of Dehydrex. We believe that the favorable patient acceptance of HypoTears is more likely due to this unusually high oncotic pressure than to its hypoosmolality. Such an artificial tear formulation should be effective in ameliorating microcystic epithelial edema and in increasing impaired epithelial adhesion to the underlying tissue in the cornea.

*****************

Rebecca posted the following on Dehydrex, which just completed clinical trials:

http://dryeyedigest.blogspot.com/200...-dehydrex.html

[Lucy]

The more I read about all this, the more confused I become. I've seen a lot of stuff (and ideas) come and go over 8 years. I still use what feels best TO ME and obviously nothing I think will harm me.

Dry eye is as individual as we are. That's why there are so many drops, people buy them. What works now and for the past two years may stop working for you--and then you try something else. I do not even try to keep up on the scientific stuff, I leave that to the people with normal eyes and a brain slanted to the scientific. As "what comedian" says, "that's not my job."

[Terri]

Liz: I think you may be right. I spent some time trying to find links and information about hypotonic, hypertonic and isotonic eye drops to see if I should focus on one kind or the other and, like Lucy, the more I read the more confused I became. I (think) I read that hypertonic eye drops can promote healing of the ocular surface. I also (think) I read that hypotonic eye drops can heal the ocular surface. So, maybe it depends on other factors.

It seems the only way to understand which would works better for a particular individual is to find a doctor who will assess the osmolarity of your tear film. Heck, I can't even find a doctor who will calculate a TBUT, so I think I'm pretty much out of luck for a more sophisticated analysis.

I guess the answer is to use one kind or the other and see if your eyes explode. If they do, then, hey... you should have used the other kind. It's a good thing I only have one dry eye. If I trash it by using drops with the wrong oncotic pressure, I can wear an eye patch and some of that pirate eyeliner I read about on one of the other threads on this board.

[Rebecca Petris]

Hypertonicity is usually recommended in cases of a chronically damaged epithelium (from ABMD, RCEs etc). I think the idea generally is that when the epithelium fails to regulate moisture levels within the epi, a hypertonic agent is useful for drawing excess moisture out, allowing the epithelium to compact and repair itself. The best-known hypertonic product on the market is Muro 128 (drops or ointment). That's no panacea for those conditions to be sure but it helps a lot of people manage the condition and I think many of those same patients benefit from Dwelle.

High oncotic pressure is more complex and has considerably broader applications... at least, based on studies that have been done on high oncotic pressure products and anecdotally on the wide variety of folks that have benefitted from it over the years.

As regards harming ourselves with using the "wrong" drops... personally the only circumstances under which I really worry about people harming themselves with any FDA compliant over-the-counter lubricants are in these situations:

• If they're being applied too frequently. My suggestion for anybody who's doing this is eyewear, eyewear, eyewear.
• If conditions other than aqueous tear deficiency (MGD, allergies, etc) are not being addressed. All the drops in the world aren't going to help and may just make things worse IMHO.
• If the drop contains harmful preservatives.

(JUST MY PERSONAL OPINION - HEAVEN KNOWS I'M NO MEDICAL AUTHORITY!!!)

[Terri]

Rebecca: Thank you, thank you, thank you for the lucid explanation. After I waded through a few papers trying to understand this earlier today, I was thoroughly befuddled. On the positive side, I learned a few new words, like "deturgescent," which I will spring on my friends when they least expect it.

[Rebecca Petris]

On the positive side, I learned a few new words, like "deturgescent," which I will spring on my friends when they least expect it.

LOL!!! Who needs Reader's Digest "Word Power" when we've got Medline.

While I was chatting recently with the man running the Dehydrex clinical trials, I let slip something about high oncotic pressure. There was a pregnant silence till he tried to express, or maybe suppress, his incredulity that I'd actually HEARD of oncotic pressure. I reassured him that though I could pronounce it, l had no idea what it really meant.

[Klee]

"what drops are hypotonic and what drops are hypertonic ?"

sazy123 intelligently asked this question time ago...i would be interested too.....since i just discovered that Refresh drops can create more damage instead of healing an Evaporative Dry Eye (since in this type of Dry Eye osmolarity increases and the tear becomes hypertonic..too salty). Surely Theratears are Hypotonic....

It's time to ask ourselfs .."Is this drop good for my case?" instead of "i like how this drop feels"

Refresh lubricant eye drops now make my eyes feel dry. If i apply them before bed I wake up with bloodshot eyes. They never used to do that. I wont use them now.