If yawning does lower IOP, has anyone integrated frequent yawning into a program to keep IOP down?
One yawn, due to the relaxation response, may indeed temporarily lower IOP. But you aren't interested in one yawn -- you are interested in a program for long term IOP maintenance, right?
The research I have been doing over the last two years indicates that frequent yawning may not be a helpful practice. It's a complex topic. I plan to cover this topic in great detail in future work. I will come back and update this answer when I have more definitive information.
For now, I will suggest that when you do yawn, on the exhalation following your deep inhalation, exhale as long as possible and as deeply / completely as possible. The next few breaths following the yawn should also be slower than normal. With this practice you won't lose any of the responses triggered by yawning, but you will counter the potential unwanted side effects.
Natural and spontaneous yawns (as opposed to a program of purposeful frequent yawns) are almost certainly fine, but I still do the above steps whenever I yawn. Once you yawn like this, you will find that it actually makes the yawn even better. The long exhalation enhances your relaxation response.
Would anyone with a home device consider doing a trial to see what happens with yawning and report back to members? It is easy for most people to yawn intentionally and do several yawns in a few minutes...enough to test.
Yes, an experiment would be a good idea. (But we need one that monitors results over a period of months.) If anyone wants to do this, I would like to speak with you in more detail. I may be able to offer you assistance or guidance.
I would love to see someone do this experiment using a tonometer, a pulse oximeter and a capnograph (also called a capnometer). I do have all that equipment, but I am not willing to do the frequent yawning test because yawning does the opposite of what I personally want to achieve right now.
Enlivened.com already rents tonometers, and in the near future Enlivened will rent capnographs as well.
Furthermore, I believe that ophthalmologists should perform capnography while checking a patient's IOP to determine if the patient is breathing normally. If the patient is not breathing normally, it is likely that the current IOP reading is not accurate for that patient. This should become the new gold standard in the clinic: tonometry with simultaneous capnography. Capnography is super easy for the patient. It is a non-event. Absolutely nothing to it. It is also very easy for the doctor/technician. Yet it adds incredibly valuable information that is highly useful for both patient and doctor.
Yawning definitely changes the brain and it has been found to change the temperatures in the eye, brain, face, sinuses.etc...so a significant effect in and around the eyes and the nerves affecting the eyes. Yawning could be an important way to normalize the brain signaling that keeps the IOP levels healthy and optimal.
Yawning also changes a lot of other things, one of which is the carbon dioxide level in the blood. It reduces end-tidal CO2, which will, if sustained, reduce blood flow to the brain and eyes as well as potentially change the CSF pressure behind the eye, which is relevant for glaucoma. However, the technique I suggested above counters these unwanted effects.
I would like to see us, as a community, do experiments with yawning and IOP. As we gather more data on this topic, we can add new answers here.