How sleep position may affect dry eye

Cornea
January 2018

by Maxine Lipner
EyeWorld Senior Contributing Writer

Researchers found sleeping face down or on one’s side increases chances of dry eye disease

Dry eye is the single most common reason that patients come into a practitioner’s office, with a prevalence of around 40% of those seeking ophthalmic care, according to Hank Perry, MD, Ophthalmic Consultants of Long Island, New York. What may not be clear in an office visit is that the patient’s sleep position may be a prime factor in his or her condition.

Elderly man and woman lying on their side in bed

In a study published in Cornea, investigators found that those who sleep face down or on their side were more likely to have dry eye disease.1 The idea that sleep position might be a contributor to dry eye is one that investigators had been considering for some time. “We had been following patients for a long time, and we came to the realization that sleep position plays a significant role,” Dr. Perry said. “It started about 15 years ago when we published a paper on floppy eyelid syndrome with Eric Donnenfeld, MD, as the lead author.”

Investigators found that patients who slept in a characteristic way with their hand or their pillow pressed against their eye had significant floppy eyelid syndrome, Dr. Perry explained, adding that this ended up resulting in ocular surface disease and dry eye. “We have been following patients subsequently and have found that they also have significant meibomian gland disease,” he said. This is in keeping with the DEBS theory of dry eye disease being secondary to chronic biofilm formation leading to meibomian gland dysfunction (MGD) and dry eye disease.3

Nocturnal positioning

Included in the study were 100 patients who had been coming in with complaints of dry eye disease, particularly with meibomian gland issues, as well as 25 age-match control subjects. “We did a survey on their sleep position and found relationships between MGD and sleeping position,” Dr. Perry said. “Patients that slept on their side or stomach fared worse than those who slept on their backs. We postulated that these patients predominantly slept on their face or pressing against an eye with covers or pillows that were mechanically clogging their meibomian glands leading to chronic inflammation and worsening dry eye signs and symptoms.”

Using lissamine green staining, investigators found that for those who slept on their back compared with their left side, there was statistically significant diminution or lessening of dry eye. The Ocular Surface Disease Index score for those who slept on either side was also found to be elevated compared to those who slept on their backs. Dr. Perry was surprised by how strong the association was, with back sleepers faring far better than others in the study. “They had less meibomian gland disease and better ocular surfaces because their meibomian glands were functioning better,” he said. “As you would expect, patients who slept on their side had worse dry eye disease on the side that they slept on.”

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.

From a clinical perspective, Dr. Perry views the results as helpful for diagnosing and treating dry eye. “What we’ve learned is that when patients come in with ocular surface disease, especially if it’s more unilateral, we need to evaluate the lid function and ask questions about how they sleep,” Dr. Perry said, stressing that this will help diagnose the cause of the disease. Treating the disease if it’s resulting from sleep position may not be as straightforward. “It’s difficult to get patients to change their sleep habits,” Dr. Perry said. “But if you alert them to this issue, it does allow them to try.” In cases where patients have significant disease and nothing else has worked, Dr. Perry has recommended that patients wear shields or goggles when they sleep to protect the ocular surface. “We’ve had good success by doing that and with lid hygiene,” he said.

Potential aggravating factors

The issue of sleep position may be exacerbated by other conditions as well. “This is also part of the problem of obesity in America in that as people have gained weight and they sleep on their faces, the head acts as a fulcrum,” Dr. Perry said.

There is more pressure placed on the eyelid because their weight is not being distributed evenly over their bodies. As a result, it’s being displaced to their stomach and their heads. “I think that is one of the reasons that we’re seeing more meibomian gland dysfunction, more sleep apnea, and more floppy eyelid syndrome,” Dr. Donnenfeld said.

Sleep position effects may go beyond meibomian gland disease. There’s a possibility that this may also have an effect on aqueous deficiency, Dr. Donnenfeld thinks. “But the area where it has a much more profound effect is on keratoconus,” he said. Those who have a habit of sleeping on their eyes have a higher risk of keratoconus. “That’s highly associated with sleep position,” Dr. Donnenfeld said. “If they have asymmetry in keratoconus, we find that they sleep on the side where the keratoconus is the worst.”

Drs. Perry and Donnenfeld hope that practitioners come away from the study with the realization that sleep position plays a significant role in ocular surface disease. “Recognizing this allows you to diagnose the disease and develop better treatment plans,” Dr. Donnenfeld concluded.


References

  1. Alevi D, et al. Effect of sleep position on the ocular surface. Cornea. 2017;36:567–571.
  2. Donnenfeld ED, et al. Keratoconus associated with floppy eyelid syndrome. Ophthalmology. 1991;98:1674–8.
  3. Rynerson JM, et al. DEBS – a unification theory for dry eye and blepharitis. Clin Ophthalmol. 2016;10:2455–2467.

Editors’ note

Drs. Donnenfeld and Perry have no financial interests related to their comments. 

Contact information

Donnenfeld: ericdonnenfeld@gmail.com
Perry: hankcornea@gmail.com