menthol sensation: physiological cause?
Thank you so much, Dr. Holly, for joining us here. I am in complete awe of your work, and I daily live the remarkable experience of using some of your unique formulae.
If time permits, and at your convenience, would you please go ahead and post those 10 fallacies that you teach to your medical audiences? I have noted several of these on your slides regarding post-LASIK dry eye care, but would just love to have the complete list.
On a related front, in your work, have you ever identified the cause or causes of what some patients describe as "menthol sensation," which is a raw, cold feeling, as if wind is blowing directly on the eye surface? If you are familiar with this sensation, can you suggest which of your 3 OTC drops might address it?
Last edited by Rojzen; 23-Jan-2008 at 10:26.
Ten Fallacies (Verities take longer)
You are all very kind! Here are the fallacies:
Fallacy No. 1 The tear film needs mechanical shoring up. (gel-like structure?)
Fallacy No. 2 Upper lid functions as a Windshield Wiper
Fallacy No. 3 The Lid Glides over the Lipid Layer
Fallacy No. 4 Major cause of Dry Eye is Evaporation
Fallacy No. 5 Lipid Layer significantly Retards Evaporation
Fallacy No. 6 Tear Film Hyperosmolality is the Main Cause of Tissue
Damage in Dry Eyes.
Fallacy No. 7 Hypotonic Artificial Tears can be Effective in Reversing
Cellular Damage in Dry Eyes
Fallacy No. 8 The Upper Lid Lubrication is of the Boundary Type
Fallacy No. 9 Lipid-rich Ointments should be Employed in
Dry Eye Management
Fallacy No. 10 Antibiotics and/or Steroids are Warranted in the
Management of Dry Eyes.
[continued with a possible explanation for the Menthol Sensation in the eye]
Last edited by Frank Holly PhD; 30-Jan-2008 at 17:46.
Menthol sensation in the eye
It is an interesting problem. Of course, most problems are interesting .
I have not heard of them but again I am not active in clinical practice.
One thing I can think of is an increase in tear evaporation rate no matter what the reason is. If one considers that it takes a tremendous amount of heat to evaporate water (540 calories per gram at the boiling point), much more than most other liquids, then it should be no wonder that increased evaporation rate could produce a cool sensation. [If you are wondering why menthol is producing such sensation even though its heat of evaporation is much lower than that of water, this is so because the vapor pressure of menthol is high at body temperature.]
BTW I m not sure this is the explanation but if it is not, I hope somebody will post the real reason, so we all can learn.
Last edited by Frank Holly PhD; 01-Feb-2008 at 10:13.
Reason: typo, grammar
I've had the menthol sensation and I just remebered today that when I wore RGPs years ago, I had the same sensation, the next day, after wearing them all day, and I would be unable to wear my lenses the following day. It was some years back and at the time I had no idea I had a budding dry eye problem...but now of course, that makes it all the more clear... Menthol sensation has changed now I use Dwelle at night, but sometimes I do still do get it mildly. It's like the whole of your eye has been dipped in a mild menthol cough sweet mixture and the effect is evaporating.
In case it brings another view to when the menthol thing might happen.
just keep swimming...