Side and stomach sleepers: Faring worse with dry eye... and possibly MGD?
A study by Hank Perry et al (OCLI) was published in Cornea last year showing that dry eye patients who sleep on their side or face down have more dry eye than those who sleep on their backs:
A statistically significant difference was shown with back sleeping compared with left side sleeping using lissamine green staining (analysis of variance, P = 0.005). The Ocular Surface Disease Index score was also found to be elevated in patients who slept on their right or left side (36.4 and 34.1, respectively) as opposed to back sleepers (26.7) with P < 0.05.
That was not nearly so startling as Dr Perry's comments about MGD in an article in this month's EyeWorld, because while the study results specifically stated that there was no statistically significant correlation between sleep position and degree of MGD, Dr Perry and colleagues clearly feel sleep position really does matter to the meibomian glands. For example:
The authors theorized that the problem is a mechanical one. The glands are fairly delicate and they function perfectly when there is nothing compressing them, but if you compress the glands, you have a direct effect on their ability to function, and this in turn leads to increased inflammation in the glands with eventual dropout and increasing severity of meibomian gland dysfunction.
Quite a theory.
This is a topic of keen interest to me. At the Dry Eye Shop we work daily to try to help people find dry eye products - not just gels and ointments but goggles, masks, shields, patches and tapes - that can increase the moisture in their eyes overnight without disrupting their sleep patterns. Their choice of products in many cases is limited by their sleep style - for reasons of safety as much as comfort.
Many people, for example, come to us after a doctor's referral and ask for a mask or goggle that will hold their lids down. This always concerns me, for reasons such as:
If the lids aren't fully closing, what will happen if the mask slips? They might be at risk of a corneal abrasion.
If they sleep on their side or stomach, won't it press on their eyes and give them blurry vision in the morning, or worse?
If they adjust the mask or goggle too tightly, might it not press dangerously on their eyes, even if they sleep on their back?
So, in my personal recommendations, I have found myself trending more and more towards encouraging people to employ tools that will, without pressing on or even touching their eyelids, block air movement and hold moisture over their eyes.
the vaulting shields made by Eye Eco (EyeSeals 4.0, Onyix and Quartz), which, though flexible, will vault the eyes unless pressed down;
bubble type bandages like NITEYE and Ortolux, which are stiff enough to hold up to some pressure and keep anything from touching the eyes;
post surgical shields such as the LASIK goggle, in extreme cases such as patients with floppy eyelid syndrome, where they must have secure, rigid protection to prevent literally rubbing the eyes (and corneas) on the bedding, or unconsciously rubbing the eyes with their hands during sleep.
In the cases where their doctor insists the lids be held shut, I encourage them to use skin-friendly silicone medical tapes or EyeLocc strips as opposed to masks or Tranquileyes. (To be clear - I think that if you're willing to put in the extra work to customize thickness of the Tranquileyes pads to get a very light pressure, it can work quite well for back sleepers - yet the safety factors remain a concern because they're so patient-specific.)
Then of course there are a host of special cases. Fibromyalgia, multiple chemical sensitivities and innumerable others introduce complicating factors that make the night solutions require ever more creativity. Nevertheless, it can be done!
But to return to the point of the study and the news report in EyeWorld: Is it really possible that physical compression of the meibomian glands from your sleep style could have a direct knock-on effect on your meibomian glands?
I eagerly await solid medical studies to answer this question.