07 December 2019

CPAP Air coming out of the Eyes

“Do not go where the path may lead, go instead where there is no path and leave a trail.” 
- Ralph Waldo Emerson (American Essayist & Poet – 1803 - 1882)

Over the next few blog posts I will detail how to stop CPAP air coming out of the eyes using a sleep apnea machine. Before doing so, I will make some comments about a research study published online in August 2018. In addition, I will explain why using a total face mask is not the answer for many people as the sleep medical specialists and equipment suppliers may advise to stop air coming through the eye tear ducts or nasolacrimal ducts and out of the eyes.  

A Novel Treatment for Nasolacrimal Air Regurgitation Into the Eye With CPAP: The Total Face Mask. Wrede JE, Parsons EC, Watson NF. J Clin Sleep Med. 2018;14(8):1415–1417.

1. The sleep medical researchers are saying that they have come up with a “Novel” treatment of using a total face mask. However, a review of the various sleep apnea forums shows that using a total face mask has been mentioned many times on the forums since at least 2004. That is, nearly 14 years before this research study was published!   

2. The study uses just 1 patient as the basis of its research using mean pressure of only 9 cmH2O. Also noted is that the patient used the mask for what I consider a low average of 4 hours and 44 minutes per night for 90% of nights over a 30 day period. In addition, the patient had a high average AHI of 3.7 events/ h when compared to successful users on the various sleep apnea forums.
Given that only 1 patient was used and the average for all patients is estimated at 10 cmH2O, it is considered this is insufficient research to justify the use of a total face mask by sleep medical specialists and equipment suppliers. In addition, when I use a total face mask with pressure up to 17 cmH2O, air still comes through one of my eye tear ducts and out of the eye.  
3. A total face mask is a very hard mask to tolerate for many people. It is a mask of “last resort” when all other masks such as nasal pillows and nasal have failed. I found the mask a little claustrophobic due to the mask covering the whole face and it felt hot on the face due to the large thickness of the silicone mask surface sitting on your face. In addition, I could not sleep properly on my side due to the mask being bulky and the mask at times leaked badly, waking me up during the night.      
4. On the Blog Post Why NOT to use a CPAP Humidifier? I advised to breathe through your nose. Breathing through your mouth using a Full Face Mask and a Total Face Mask will lead to dry sore throat and dry mouth and possible dental health issues such as bad breath.
The nose is like a humidifier whereby it will warm, humidify and moisten the air that you are breathing in. In addition, breathing through your nose kills deadly bacteria and viruses and traps dust particles. This is one of the reasons serious consideration should be given to using nasal pillows and nasal masks where possible. 

5. Many patients have found their “perfect” or at least their preferred mask. Why would they want to change from their existing mask such as a nasal mask and use a total face mask with all its potential drawbacks? 
One of the hardest and most difficult aspects of using a sleep apnea machine is to find your “perfect” mask. A mask that is properly fitting and comfortable will strongly enhance a person’s experience, acceptance and long-term use of the sleep apnea machine. Why change mask after spending in some cases, a lot of time and money working out the “perfect” mask for them? Details of my "perfect" mask being a nasal mask are on the blog post Stop CPAP Mask Problems and Issues.

6. The research study states that the reason the patient was able to use a total face mask is that “a total face mask allows equalization of pressure on both sides of the lacrimal system.” This is absolute NONSENSE! Take this statement from someone who regularly uses a sleep apnea machine, uses maximum pressure up to 17 cmH2O, has used a total face mask and had 2 eye tear duct dacryocystorhinostomy (DCR) operations, one on each eye. This is more than most if not 100% of all the sleep medical specialists!   

Why has the pressure not equalized as stated by the sleep medical researchers? The reason is that the pressure has not changed. For example, should I use CPAP fixed pressure of 9 cmH2O, then the pressure stays all night at 9 cmH2O! The pressure of 9 cmH2O does not change when air is coming out of the eye tear duct. It is the velocity or force of the air that has changed.

Force = Pressure x Area of opening of the tear duct Vs Area of the whole eye. 

To explain further the reason why, I use an everyday example. Go into the backyard and fill up a bucket with water using a hose. Put your finger over part of the end of the hose, what happens? The water comes out or shoots out faster and further. This is similar to the eye tear duct which is very narrow compared to the whole area of the eye. Whilst the air pressure is the same; the air is coming out faster and further from the eye tear duct due to the smaller area or opening of the tear duct. 

Now ask yourself the question, does the bucket fill up with water faster with your finger over the end of the hose when compared to not using your finger? The answer is NO! You need both pressure and flow or volume of water. That is, whilst the force of the water has increased; the volume of water has reduced.


The reason the air does not come through the eye tear duct and out of the eye in the sleep medical researchers study is due to the reduced volume of air using the total face mask and that the mean pressure used in the study is low at 9 cmH2O. It is not due to the equalization of pressure using a total face mask. As mentioned, when I use a total face mask with pressure up to 17 cmH2O, air still comes through one of my eye tear ducts and out of the eye.  
The example of filling up a bucket with water is basic physics which the sleep medical specialists would have learnt at school. Refer to an article including video written by the Children’s Museum of Houston, USA.
Some medical specialists will argue that water and air are completely different. Whilst the density may be drastically different, the principles applying to each are similar in that both water and air are fluids. This is most noticeable when a person uses humidification with their sleep apnea machine.  
The principle of filling up a bucket with water is critical to understanding how to stop CPAP air coming through the eye tear ducts and out of the eyes using a sleep apnea machine. In addition, a person can use any type of sleep apnea mask. It is a great example of the lack of understanding by the sleep medical specialists of how the sleep apnea machines and sleep apnea therapy truly work. As the sleep specialists are not educating themselves and their patients, it will be up to you to educate yourself!  

Since originally writing this blog post, in early 2021 I began using a very high starting IPAP of 18.2 cmH2O and EPAP of 13.0 cmH2O (inhale and exhale pressure) which may cause air coming out the eyes. Top pressure during the night may be more than 20 cmH2O! This was essential to stop hypoxia (oxygen desaturation) and sleep disordered breathing causing the symptoms of Dementia. More details are on the blog post: 

What BiPAP Settings prevent Alzheimer's due to REM sleep breathing issues?

Further details on how to overcome the issue of air through the eye tear duct and coming out the eyes using any sleep apnea mask and how two Aha moments gave me the answer are on the following blog posts:

Air through Eye Tear Duct - Introduction 

How to Stop Eye Tear Duct Air Regurgitation? 

CPAP Settings to Stop Air coming out the Eyes

CPAP Air out Eyes and Tear Ducts: Other Options

CPAP Air out Eyes and Tear Ducts: Other Options (Part 2)
Should you be having side effects and issues with your sleep apnea therapy; CHANGE what you are doing so that you can wake up feeling refreshed and energized each day. 
“Have courage. Be adventurous and Go for it! Overcome your fear.”
- Mrhelpful