You may find it surprising that, for many people suffering from dry eye disease, nighttime can be the most damaging part of the day. It is easy to think that while we’re sleeping and our eyes are closed, the surface of our eye is protected. But the truth is that there are several undercover causes of dryness that can occur overnight and worsen the symptoms of dry eye disease. These conditions are often overlooked, and many people may not realize their eyes are at risk each and every night. Read on to learn how nighttime dryness can affect the eyes and to learn whether or not you are at risk.
One condition that can greatly increase the risk of nighttime dryness is nocturnal lagopthalmos. In nocturnal lagophthalmos, the eyelids do not close completely during the night. The degree of lagophthalmos can be variable; the upper and lower eyelids may only be a millimeter apart, or a large portion of the eye may be exposed. Any time the eyelids do not properly close throughout the night, the front surface of the eye is at risk. In these cases, the tears can evaporate, leaving the cornea malnourished for long periods of time. Eye doctors can identify those at risk for nocturnal lagopthalmos by evaluating the eye’s front surface, particularly the lower portion of the eye which is most commonly exposed when the eyelids are not closed during sleep. If your doctor suspects you are affected by nocturnal lagophthalmos, they may recommend an overnight ointment, a thicker eye drop, or even an eye mask to keep the cornea protected throughout the night.
Sleep Apnea and Floppy Eyelid Syndrome
Sleep apnea is a sleep disorder caused by breathing difficulties during sleep, and it may increase the risk of nighttime dryness for several different reasons. For starters, many people who suffer from sleep apnea are treated with a device known as a CPAP (continuous positive airway pressure) machine. The CPAP mask is designed to fit over the mouth and nose to administer oxygen and improve breathing throughout the night. If the device fits poorly and there are air leaks, the eyes may be bombarded by a stream of dry air throughout the night, worsening dryness and causing discomfort. Furthermore, those with sleep apnea are significantly more likely to have a condition known as Floppy Eyelid Syndrome, in which the eyelids are particularly loose and have the tendency to flip over throughout the night. Floppy Eyelid Syndrome result in the front surface of the eye being exposed to dry conditions for hours at a time.
For those with sleep apnea that is worsening their symptoms of dry eye disease, the cause of the nighttime dryness must be identified. If a poorly fitting CPAP mask if the cause, then a simple adjustment may drastically reduce nighttime dryness. If Floppy Eyelid Syndrome is the culprit, the treatment options are similar to those for nocturnal lagophthalmos, including ointments, gels, and eyewear.
DRY EYES AT NIGHT
Possible causes of nighttime dryness can be identified during a comprehensive eye exam. By asking questions about symptoms and closely evaluating your eyes, your optometrist can detect and address problems that may be worsening your dry eye symptoms: even the ones that occur while you are asleep.